chore: bump version to 0.2.10

feat: 代码片段功能与 Markdown 内嵌片段渲染、文档截图等
chore: bump version to 0.2.9
2026-10-09 19:07:57 +08:00 · 2026-10-09 18:53:38 +08:00 · 2026-10-03 02:40:45 +08:00 · 2026-10-03 02:38:11 +08:00 · 2026-10-02 01:48:02 +08:00 · 2026-10-02 01:47:14 +08:00
211 changed files with 17723 additions and 1888 deletions
--- a/.gitignore
+++ b/.gitignore
@@ -8,6 +8,8 @@ out/
 .vercel/
 *.tsbuildinfo
 next-debug.log*
+# postbuild 抽取的字体声明（scripts/extract-font-css.mjs 生成）
+frontend/public/fonts/

 # ===== Go 构建产物 =====
 *.exe
--- a/220
+++ b/220
@@ -1,38 +1,202 @@
-姜十三论坛 专有软件许可协议
-Proprietary Software License Agreement
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/

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-版权所有 (c) 2026 姜十三。保留所有权利。
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-以源码可见的方式发布，但这并不构成任何形式的开源授权。
+   1. Definitions.

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--- a/README.md
+++ b/README.md
@@ -1,101 +1,128 @@
+<div align="center">
+
 # 姜十三论坛（jiang13-bbs）

-一个基于 Go + Next.js 的现代社区论坛系统，采用 SSR 直出 + HttpOnly Cookie 认证方案，具备完整的帖子/评论/通知/签到/管理后台功能。
+一个基于 **Go + Next.js** 构建的现代化社区论坛系统，SSR 直出、HttpOnly Cookie 认证，内置内容社区、代码片段、书库、积分体系、实时群聊与完整管理后台，开箱即用。

-> **许可声明：** 本项目为专有软件（Proprietary），源码可见但不构成开源授权。详见 [LICENSE](./LICENSE)。未经书面许可，不得使用、部署或分发。
+[![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](./LICENSE)
+[![Version](https://img.shields.io/badge/version-0.2.9-green.svg)](./VERSION)
+[![Go](https://img.shields.io/badge/Go-1.27-00ADD8?logo=go&logoColor=white)](https://go.dev/)
+[![Next.js](https://img.shields.io/badge/Next.js-16-black?logo=nextdotjs&logoColor=white)](https://nextjs.org/)
+[![PRs Welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg)](#贡献指南)
+
+</div>
+
+---
+
+## 目录
+
+- [项目截图](#项目截图)
+- [功能特性](#功能特性)
+- [技术栈](#技术栈)
+- [快速开始](#快速开始)
+- [配置说明](#配置说明)
+- [Docker 部署](#docker-部署)
+- [项目结构](#项目结构)
+- [安全设计](#安全设计)
+- [开发与测试](#开发与测试)
+- [更新日志](#更新日志)
+- [贡献指南](#贡献指南)
+- [许可证](#许可证)
+- [联系方式](#联系方式)
+- [赞赏支持](#赞赏支持)
+
+---
+
+## 项目截图
+
+| 首页信息流 | 帖子详情 |
+| :---: | :---: |
+| ![首页](docs/images/首页.png) | ![帖子详情](docs/images/帖子详情.png) |
+| 代码片段广场 | 书库在线阅读 |
+| ![代码片段](docs/images/代码片段.png) | ![书库](docs/images/书库.png) |
+| 管理后台仪表盘 | 访问统计分析 |
+| ![管理后台](docs/images/管理后台.png) | ![访问统计](docs/images/访问统计.png) |
+
+<!--
+后台设置类截图（邮件 / 过滤 / 维护 / 安全 / 存储，含移动端与暗色模式）：
+  docs/screenshots/settings/
+-->
+
+---
+
+## 功能特性
+
+### 内容社区
+
+- 帖子发布 / 编辑 / 删除，支持普通帖、**问答帖**（采纳答案、状态流转）、**投票帖**、**悬赏帖**、**抽奖帖**，以及密码帖与付费解锁内容
+- Markdown 写作与渲染：Shiki 代码高亮、目录导航、图片灯箱、视频/附件
+- 楼层化评论：主评论占楼层、子评论不占楼层，最多 10 层嵌套，单次查询拼装评论树，无 N+1
+- 评论与帖子均提供**编辑历史**、软删除与回收站（恢复 / 彻底删除）
+- 点赞、收藏、关注、置顶、推荐、锁定，联合唯一索引防止重复互动
+- 附件可设定积分价格，支持付费下载
+
+### 积分与成长体系
+
+- 每日签到 + 连续签到加成，积分余额与完整流水台账
+- 用户等级体系（经验值自动升级）与成就徽章（手动授予 / 自动通知）
+- 全站积分排行榜与个人排名
+
+### 代码片段
+
+- 独立的代码片段广场：多语言语法高亮、按语言筛选、全站统计
+- Fork、一键复制计数、片段评论、版本历史、可见性管理
+
+### 书库 / 文档中心
+
+- 书籍文档管理，两级章节（章 → 节）结构
+- 支持 **EPUB 解析导入**、Markdown 单篇 / 批量导入、整库导出与单本导出
+- 内置在线阅读器，封面、附件下载一应俱全
+
+### 私信与群聊
+
+- 一对一私信、多人群聊房间、默认全站大厅
+- 群成员管理：邀请 / 移出、禁言、角色设置；消息撤回、未读汇总、会话置顶
+
+### 实时通知
+
+- 评论、回复、点赞、@、系统通知等多类型站内消息
+- 未读红点 **SSR 首屏直出**，WebSocket 实时推送，页面回到前台时 HTTP 校准，支持单条 / 全部已读
+
+### 管理后台
+
+- 仪表盘与分析概览（Recharts 图表）
+- 内容审核队列（待审帖子 / 评论，板块管理员仅见授权板块）与内容回收站
+- 板块管理、版主授权、排序
+- 用户管理：角色、细粒度权限码、封禁、消息权限、登录日志、登录设备、积分调整
+- 公告文章、站点单页（CMS）管理
+- 广告位与赞助商配置（含用户自助购买提交、二维码、验证码）
+- 友情链接：用户申请、后台审批
+- 侧边栏可视化布局配置 + 自定义 HTML 小部件
+- 背景图、品牌 Logo 上传裁剪；全站媒体库盘点
+- **访问统计**：概览、实时、来源、页面、访客、安全、事件等多维度分析
+- 旧站数据导入（WordPress / Typecho 等）
+- 更新时间线：从 Git Commits / Releases 自动生成更新日志
+- 维护模式、系统诊断、SMTP 邮件配置（凭据加密存储）
+- 支持 S3 / MinIO 对象存储：文件内容去重、自适应图片变体、WebP 自动转换
+
+### SEO
+
+- 全站 SSR / ISR，title、description、OG 等关键内容均在初始 HTML 中
+- 帖子详情页输出 `DiscussionForumPosting` 类型 JSON-LD
+- 动态 `sitemap`、`robots`、Canonical 链接

 ---

 ## 技术栈

-| 层级 | 技术 |
-|------|------|
+| 层级 | 技术选型 |
+|------|----------|
 | 后端 | Go 1.27 · Gin · GORM · PostgreSQL 17 |
-| 前端 | Next.js 16 (App Router) · TypeScript · Tailwind CSS v4 |
-| 认证 | JWT (HttpOnly Cookie) + Refresh Token 轮转 + CSRF 双提交 + Token Version 撤销 |
-| 部署 | 官方：`deploy/` Docker Compose（Next SSR + Go + Postgres，反代自备）；本地开发仅 Compose 起数据库 |
-
---
-
-## 功能概览
-
-### 用户
-
- 注册 / 登录 / 登出（注册即登录，免二次跳转）
- 个人资料编辑：昵称、头像、邮箱、个性签名
- 修改密码（改密后全端踢下线）
- 个人主页：发帖列表、评论列表（分页）、签到积分
- 每日签到（积分 + 连续签到天数）
-
-### 内容
-
- 帖子发帖 / 编辑 / 删除（作者本人或管理员）
- 帖子类型：普通帖 / 问答帖
- 帖子置顶 / 推荐（仅管理员）
- 评论楼层制：主评论 = 楼层，子评论不占楼层，最多 10 层嵌套
- 楼层分页 + 内存拼装评论树（单次查询，无 N+1）
- Markdown 渲染（代码高亮、引用、列表等）
- 帖子点赞（联合唯一索引防重复）
-
-### 通知
-
- 站内通知：评论你的帖子、回复你的评论、点赞你的帖子
- 未读红点 SSR 直出，实时靠 WebSocket 推送，回前台时 HTTP 校准
- 单条标记已读 / 全部已读
-
-### 管理后台
-
- 公告管理（草稿 / 发布、标签预设色）
- 仪表盘
-
-### SEO
-
- 全站 SSR/ISR，SEO 关键内容在初始 HTML 中
- 帖子详情页输出 `DiscussionForumPosting` 类型 JSON-LD
- 动态 `sitemap.ts` + `robots.ts`（由 Next.js 对外提供，后端不重复挂 `/sitemap.xml` / `/robots.txt`）
-
-### 安全
-
- CSP / HSTS / X-Frame-Options: DENY / X-Content-Type-Options / Referrer-Policy
- 速率限制：登录 20/min、注册 10/min、发帖新用户 24h 冷静期
- Refresh Token 一次性轮转 + 盗用检测（吊销后重放 → 杀全家族）
- 生产 HTTPS 启用 `__Host-` Cookie 前缀
-
---
-
-## 项目结构
-
-```
-jiang13-bbs/
-├── backend/                  # Go 后端
-│   ├── cmd/jiang13/          # 入口 main.go
-│   ├── config/               # 配置解析（app.ini + 环境变量）
-│   ├── handler/              # HTTP 处理器
-│   ├── middleware/            # 认证 / CSRF / 限流 / 安全头
-│   ├── model/                # GORM 模型 + 数据库初始化
-│   ├── router/               # 路由注册
-│   ├── service/              # 业务逻辑层
-│   ├── app.ini.example       # 配置模板
-│   └── go.mod
-├── frontend/                 # Next.js 前端
-│   ├── app/                  # App Router 页面
-│   │   ├── settings/         # 账号设置（资料 + 密码）
-│   │   ├── u/[id]/           # 用户主页
-│   │   ├── post/[id]/        # 帖子详情
-│   │   ├── compose/          # 发帖
-│   │   ├── notifications/    # 通知列表
-│   │   ├── admin/            # 管理后台
-│   │   └── ...
-│   ├── components/           # 复用组件
-│   ├── lib/                  # API 封装 / 工具函数
-│   ├── middleware.ts         # SSR 登录态静默轮转
-│   ├── next.config.ts        # Rewrite 代理 / 图片缓存
-│   └── .env.example
-├── deploy/                   # 官方运行时（web + api + Postgres，反代自备）
-├── docker-compose.yml        # 仅本地开发 Postgres
-├── LICENSE                   # 专有软件许可协议
-└── .gitignore
-```
+| 前端 | Next.js 16（App Router）· React 19 · TypeScript · Tailwind CSS v4 |
+| 认证 | JWT（HttpOnly Cookie）+ Refresh Token 轮转 + CSRF 双提交 + Token Version 撤销 |
+| 实时 | WebSocket（gorilla/websocket） |
+| 存储 | 本地存储 / S3（MinIO），Markdown 引擎 Goldmark，代码高亮 Shiki |
+| 部署 | Docker Compose：Next SSR + Go API + PostgreSQL（反向代理自备） |

 ---

@@ -104,8 +131,8 @@ jiang13-bbs/
 ### 前置条件

 - Go 1.27+
- Node.js 20+ / pnpm 或 npm
- PostgreSQL 17（或通过 Docker Compose 启动）
+- Node.js 20+（npm）
+- PostgreSQL 17（可通过 Docker Compose 启动）

 ### 1. 启动数据库

@@ -123,9 +150,9 @@ go mod download
 go run ./cmd/jiang13
 ```

-**工作目录必须是 `backend/`。** 上传文件与 JWT 密钥落在 `backend/data/`（头像 `backend/data/uploads/avatars/`）。不要在仓库根或 `backend/cmd/jiang13/` 执行 `go run`，否则会另建一套 data，数据库里头像 URL 会对不上文件。启动日志应含 `workPath=.../backend` 和 `dataDir=.../backend/data`。需要覆盖时设置 `JIANG13_WORK_PATH` 指向 `backend/`。
+> **工作目录必须是 `backend/`。** 上传文件与 JWT 密钥落在 `backend/data/`（头像位于 `backend/data/uploads/avatars/`）。在仓库根或 `backend/cmd/jiang13/` 下执行会另建一套 data，导致数据库中的文件 URL 对不上。启动日志应包含 `workPath=.../backend`；需要覆盖时可设置 `JIANG13_WORK_PATH`。

-后端默认监听 `:3001`，首次启动自动执行数据库迁移并写入默认板块。同一时间只跑一个后端进程。
+后端默认监听 `:3001`，首次启动自动执行数据库迁移并写入默认板块。

 ### 3. 启动前端

@@ -136,13 +163,17 @@ npm install
 npm run dev
 ```

-前端默认监听 `:3000`，通过 `next.config.ts` rewrite 将 `/api/*` 代理到后端。
+前端默认监听 `:3000`，通过 `next.config.ts` 的 rewrite 将 `/api/*` 代理到后端。
+
+**空数据库首次注册的账号将自动成为站长。**
+
+> Windows 用户也可直接使用仓库根目录的 `start.bat`（或 `start.sh`）一键启动开发环境，停止使用 `stop.bat` / `stop.sh`。

 ---

 ## 配置说明

-### 后端（`backend/app.ini`）
+### 后端 `backend/app.ini`

 ```ini
 [server]
@@ -152,108 +183,189 @@ HTTP_PORT = 3001
 DSN = postgres://postgres:postgres@localhost:5432/jiang13?sslmode=disable

 [security]
-; 留空则自动生成并持久化到 data/.jwt_secret
-; 生产环境务必显式指定强随机值
+; 留空则自动生成并持久化到 data/.jwt_secret；生产环境务必显式指定强随机值
 JWT_SECRET =
+; 32 字节随机值的标准 Base64（openssl rand -base64 32），用于加密邮件 / S3 凭据
+SETTINGS_MASTER_KEY =

 [paths]
 DATA = data

 [app]
 DEV_MODE = true
+SITE_URL = http://localhost:3000
+CORS_ORIGINS =
 ```

-环境变量优先级高于 app.ini：`HTTP_PORT`、`DB_DSN`、`JWT_SECRET`、`DEV_MODE`。`JIANG13_WORK_PATH` 可强制指定后端根目录（`app.ini` 与 `data/` 所在处）。
+环境变量优先级高于 `app.ini`：`HTTP_PORT`、`DB_DSN`、`JWT_SECRET`、`SETTINGS_MASTER_KEY`、`DEV_MODE`、`SITE_URL`、`CORS_ORIGINS`、`TRUSTED_PROXIES`。

-### 前端（`frontend/.env.local`）
+### 前端 `frontend/.env.local`

 ```bash
-# SSR 与 middleware 直连后端（本地开发）
+# SSR 与 middleware 直连后端
 NEXT_PUBLIC_API_URL=http://localhost:3001

-# 部署到 Cloudflare Workers 等边缘环境时必须显式配置
+# 仅服务端可见；生产构建必须显式配置
 # BACKEND_URL=https://your-backend.example.com
+
+# 与后端 DEV_MODE 对齐
+DEV_MODE=true
+```
+
+完整环境变量清单见 [.env.example](./.env.example)、[frontend/.env.example](./frontend/.env.example)。
+
+---
+
+## Docker 部署
+
+官方运行时位于 [`deploy/`](./deploy/)，一体交付 **Next.js SSR + Go API + PostgreSQL 17**，不含反向代理（TLS 与同源路由由你的 Nginx / Caddy 处理）。
+
+```bash
+cd deploy
+cp .env.example .env
+# 编辑 .env：POSTGRES_PASSWORD、JWT_SECRET、SITE_URL
+docker compose up -d --build
+```
+
+然后将同一 Host 反向代理到容器：
+
+- `/` → web `:3000`
+- `/api/`（含 `/api/ws`）、`/uploads/`、`/health` → api `:3001`
+
+`GET https://你的域名/health` 返回 `{"status":"ok"}` 即部署成功。
+
+详细说明、升级与备份命令见 [deploy/README.md](./deploy/README.md)，Nginx 配置示例见 [deploy/nginx.example.conf](./deploy/nginx.example.conf)，运行时契约见 [deploy/CONTRACT.md](./deploy/CONTRACT.md)。1Panel 面板部署可参考 [docs/deploy-1panel.md](./docs/deploy-1panel.md)。
+
+---
+
+## 项目结构
+
+```
+jiang13-bbs/
+├── backend/                  # Go 后端
+│   ├── cmd/jiang13/          # 程序入口
+│   ├── config/               # 配置解析（app.ini + 环境变量）
+│   ├── handler/              # HTTP 处理器
+│   ├── middleware/            # 认证 / CSRF / 限流 / 安全头 / 访问捕获
+│   ├── model/                # GORM 模型与数据库初始化
+│   ├── realtime/             # WebSocket Hub
+│   ├── router/               # 路由注册
+│   ├── service/              # 业务逻辑层
+│   ├── markdown/             # Markdown 扩展（隐藏内容等）
+│   └── app.ini.example
+├── frontend/                 # Next.js 前端
+│   ├── app/                  # App Router 页面（含 admin 后台）
+│   ├── components/           # 通用组件
+│   ├── hooks/                # 自定义 Hooks
+│   ├── lib/                  # API 封装与工具函数
+│   ├── public/               # 静态资源（表情图等）
+│   ├── middleware.ts         # SSR 登录态静默轮转
+│   └── next.config.ts        # Rewrite 代理 / 图片缓存
+├── deploy/                   # 官方运行时（Docker Compose / Dockerfile）
+├── docs/                     # 文档与截图
+├── docker-compose.yml        # 本地开发用（仅 PostgreSQL）
+├── start.bat / start.sh      # 本地一键启动
+├── VERSION
+└── LICENSE
 ```

 ---

-## 认证架构
+## 安全设计

-采用三 Cookie + Token Version 方案，不使用 localStorage 存储 token：
+采用三 Cookie 方案，令牌不落 localStorage：

 | Cookie | 用途 | 属性 |
 |--------|------|------|
 | `j13_token` | Access JWT（15 分钟） | HttpOnly · SameSite=Lax |
-| `j13_refresh` | Refresh Token（7 天，DB 存储 SHA-256） | HttpOnly · SameSite=Lax · Path=/ |
+| `j13_refresh` | Refresh Token（7 天，DB 存 SHA-256） | HttpOnly · SameSite=Lax · Path=/ |
 | `j13_csrf` | CSRF Token（JS 可读） | SameSite=Lax |

- **SSR 直出登录态：** `middleware.ts` 在页面/RSC 请求前本地解码 access token 的 exp，过期时静默调后端 refresh 轮转，新 cookie 注入请求头供 SSR 使用并透传浏览器。
- **客户端续期：** `lib/api.ts` 的 `fetchWithRefresh` 遇到 401 自动调 `/api/auth/refresh` 重试。
- **撤销机制：** 改密码 / 封禁 / 管理员强制下线时递增 `User.TokenVersion`，所有旧 JWT 立即失效。
- **盗用检测：** Refresh Token 一次性轮转，已吊销 token 重放时撤销该用户全部 refresh token。
-
-生产 HTTPS 下 cookie 名自动启用 `__Host-` 前缀。
-
-若本机曾跑过早期构建，浏览器里可能还留着 `Path=/api/auth` 的 `j13_refresh`（HttpOnly，页面脚本删不掉）。打开开发者工具 → Application → Cookies，删掉该条，或对该源执行「清除站点数据」。之后只应存在 `Path=/` 的三枚 cookie。
+- **SSR 直出登录态**：`middleware.ts` 在渲染前检查 Access Token 过期时间，过期则静默轮转，新 Cookie 同时供 SSR 使用并透传浏览器
+- **Refresh Token 一次性轮转 + 盗用检测**：已吊销 Token 被重放时，撤销该用户全部 Refresh Token
+- **Token Version 撤销**：改密 / 封禁 / 强制下线时递增版本号，旧 JWT 立即失效
+- **速率限制**：登录、注册、发帖（新用户 24h 冷静期）、评论、上传等分级限流，管理员豁免
+- **安全响应头**：CSP、HSTS、X-Frame-Options: DENY、X-Content-Type-Options、Referrer-Policy
+- 生产 HTTPS 下 Cookie 自动启用 `__Host-` 前缀，要求前后端必须**同源部署**（不能拆分到子域）

 ---

-## 部署
-
-**官方运行时是 `deploy/docker-compose.yml`（Next SSR + Go + Postgres，不含反代）。** 说明与升级命令见 [deploy/README.md](./deploy/README.md)，Nginx 示例见 [deploy/nginx.example.conf](./deploy/nginx.example.conf)，契约见 [deploy/CONTRACT.md](./deploy/CONTRACT.md)。
-
-本地开发仍用仓库根 `start.bat` / `start.sh` 与根目录 `docker-compose.yml`（只起 Postgres）。不要把开发流程改成必须打应用镜像。
-
-更新应用（镜像已发布时）：
+## 开发与测试

 ```bash
-cd deploy
-docker compose pull
-docker compose up -d
+# 后端测试
+cd backend && go test ./...
+
+# 前端测试（Node 内置 test runner）
+cd frontend && npm test
+
+# 前端代码检查
+npm run lint
 ```

-后台一键更新、预编译包不在本期。Cloudflare Workers 不是官方运行时。
+开发约定：

-### 生产环境要点
-
-1. **官方 Compose：** `DEV_MODE=false`，强随机 `JWT_SECRET` 与 `POSTGRES_PASSWORD`；由你现有的 Nginx/Caddy 提供 HTTPS，并把页面与 `/api`、`/api/ws`、`/uploads` 挂到同一 Host。
-2. **CORS 与 Canonical：** 设 `SITE_URL` 为对外 origin（不要改 `router.go` 写死域名）。官方 Compose 会同时注入 api 与 web；web 用它生成 Canonical / sitemap，不要填 `http://api:3001`。
-3. **自管部署：** 仍须同源反代。Workers 前端须保持 `middleware.ts` 文件名（OpenNext 不识别 `proxy.ts`），实时通道由反代承接 `/api/ws`。
-
-### WebSocket（开发 vs 生产）
-
-浏览器发起 WebSocket 握手**一定会带 `Origin`**。后端拒绝空 Origin，这只挡住 curl / 脚本探测，**不影响 `npm run dev`，也不影响生产浏览器**。
-
-**开发环境（`DEV_MODE=true`）**
-
- 页面在 `http://localhost:3000`，WS 直连 `ws://localhost:3001/api/ws`（Next.js rewrite 不透传 `Upgrade`）。
- 二者端口不同，不是浏览器意义上的同源。后端因此放行 Origin 主机为 `localhost` / `127.0.0.1` 的**任意端口**。
- Cookie 不按端口隔离，`:3000` 上的 `j13_token` 会随握手带到 `:3001`。不要把 `DEV_MODE` 改成 `false` 再跑这对端口，否则 Origin `localhost:3000` 对不上 Host `localhost:3001`，握手会被拒。
-
-**生产环境（`DEV_MODE=false`）**
-
- Origin 的 host（含端口）必须与请求 `Host` **完全一致**。请用 Nginx/Caddy 把前端与 `/api/`、`/api/ws` 挂到同一域名，例如 `https://bbs.example.com`。
- 反向代理需透传 `Upgrade`、`Connection`，并保留原始 `Host` / `Origin`。
- 生产 cookie 使用 `__Host-` 前缀，要求 `Secure`、`Path=/`、**不能设 Domain**。因此 API **不能**放到 `api.example.com` 这类另一子域，否则登录 cookie 与 WS 都会失效。
- Cloudflare Workers / OpenNext **不能**透传任意 WebSocket。若前端部署在 Workers，实时通道必须由同源反代（Nginx 等）承接 `/api/ws`，而不是指望 Workers 升级连接。
- 可用 `NEXT_PUBLIC_WS_URL` 覆盖前端连线地址；一旦覆盖，Origin 仍须与后端看到的 Host 一致。
+- Next.js 16 中 `params` / `searchParams` / `cookies()` / `headers()` 均需 `await`
+- 权限校验只在 Go 后端执行，前端不做判定
+- 配色仅修改 `frontend/app/globals.css` 中的 CSS 令牌，不在组件内硬编码颜色
+- 所有公开页面保持 SSR / ISR，SEO 关键内容必须在初始 HTML 中

 ---

-## 开发约定
+## 更新日志

- **Next.js 16：** `params` / `searchParams` / `cookies()` / `headers()` 必须 `await`。
- **SEO：** 所有公开页面 SSR/ISR，SEO 关键内容（title、description、OG、JSON-LD）必须在初始 HTML 中。
- **权限：** 权限校验只在 Go 后端执行，前端不做判定。
- **配色：** 仅修改 `frontend/app/globals.css` 中的 CSS 令牌，禁止在组件内硬编码颜色。
- **无障碍：** 文字对比度 ≥4.5:1，交互控件边界 ≥3:1（WCAG 2.1 AA）。
+版本发布与部署契约变更记录见 [deploy/CHANGELOG.md](./deploy/CHANGELOG.md)，当前版本 **v0.2.9**。
+
+---
+
+## 贡献指南
+
+欢迎提交 Issue 与 Pull Request！
+
+1. Fork 本仓库并创建特性分支：`git checkout -b feature/your-feature`
+2. 提交前请确保测试通过：后端 `go test ./...`，前端 `npm test`
+3. 提交代码并推送分支
+4. 在 GitHub 上发起 Pull Request，描述清楚改动内容与动机
+
+- 提交信息建议遵循 [Conventional Commits](https://www.conventionalcommits.org/) 规范（`feat:` / `fix:` / `docs:` 等）
+- 发现安全问题请**不要**直接提 Issue，发送邮件至 aarbbs@88.com 私下反馈

 ---

 ## 许可证

-**专有软件（Proprietary）** — Copyright © 2026 姜十三，保留所有权利。
+本项目基于 [Apache License 2.0](./LICENSE) 开源。

-源码仅可见，未经书面许可不得使用、部署、修改或分发。详见 [LICENSE](./LICENSE)。
+```
+Copyright 2026 姜十三

-联系方式：aarbbs@88.com
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+```
+
+---
+
+## 联系方式
+
+- QQ：97975089
+
+- 邮箱：97975089@qq.com
+
+- Issue：[GitHub Issues](https://github.com/aarbbs/jiang13-bbs/issues)
+
+---
+
+## 赞赏支持
+
+如果本项目对你有帮助，欢迎请作者喝杯咖啡 ☕，你的支持是持续维护的动力。
+
+<p align="center">
+  <img src="docs/images/wechat.png" width="220" alt="微信打赏" />
+  &nbsp;&nbsp;&nbsp;&nbsp;
+  <img src="docs/images/zfb.png" width="220" alt="支付宝打赏" />
+</p>
+
+<p align="center">微信打赏 &nbsp;&nbsp;|&nbsp;&nbsp; 支付宝打赏</p>
--- a/2
+++ b/2
@@ -1 +1 @@
-0.2.5
+0.2.10
--- a/backend/config/config_test.go
+++ b/backend/config/config_test.go
@@ -257,7 +257,7 @@ func TestEnsureAppIniBackfillsMissingKeys(t *testing.T) {

 func TestParseSiteURLFromIni(t *testing.T) {
 	work := t.TempDir()
-	body := "[security]\nJWT_SECRET = "+testJWTSecret+"\n\n[app]\nDEV_MODE = true\nSITE_URL = https://forum.example.com/\nCORS_ORIGINS = https://a.example.com, https://b.example.com/\n"
+	body := "[security]\nJWT_SECRET = " + testJWTSecret + "\n\n[app]\nDEV_MODE = true\nSITE_URL = https://forum.example.com/\nCORS_ORIGINS = https://a.example.com, https://b.example.com/\n"
 	if err := os.WriteFile(filepath.Join(work, "app.ini"), []byte(body), 0600); err != nil {
 		t.Fatal(err)
 	}
--- a/backend/handler/admin_legacy_import.go
+++ b/backend/handler/admin_legacy_import.go
@@ -119,7 +119,7 @@ func optionalLegacyZip(c *gin.Context, field, pattern, label string) (string, bo
 		return "", true // 字段不存在，视为未上传
 	}
 	if fh.Size > service.LegacyZipMaxBytes {
-		c.JSON(http.StatusRequestEntityTooLarge, gin.H{"error": label+"不能超过 128MB"})
+		c.JSON(http.StatusRequestEntityTooLarge, gin.H{"error": label + "不能超过 128MB"})
 		return "", false
 	}
 	path, err := saveMultipartToTemp(fh, pattern)
--- a/backend/handler/admin_user.go
+++ b/backend/handler/admin_user.go
@@ -94,6 +94,41 @@ func (h *Handlers) AdminSetUserMessages(c *gin.Context) {
 	c.JSON(http.StatusOK, gin.H{"user": user})
 }

+// AdminGetUserPerms 读取账号级渠道权限（超管/站长，授权弹窗回显用）
+func (h *Handlers) AdminGetUserPerms(c *gin.Context) {
+	id, ok := parseAdminUserID(c)
+	if !ok {
+		return
+	}
+	perms, err := h.AdminUser.GetPermOverrides(middleware.CurrentActor(c), id)
+	if err != nil {
+		respondAdminUserError(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"perm_overrides": perms})
+}
+
+// AdminSetUserPerms 授予/撤销账号级渠道权限（超管/站长）
+func (h *Handlers) AdminSetUserPerms(c *gin.Context) {
+	id, ok := parseAdminUserID(c)
+	if !ok {
+		return
+	}
+	var body struct {
+		Perms []string `json:"perms"`
+	}
+	if err := c.ShouldBindJSON(&body); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效"})
+		return
+	}
+	user, err := h.AdminUser.SetPermOverrides(middleware.CurrentActor(c), id, body.Perms)
+	if err != nil {
+		respondAdminUserError(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"user": user})
+}
+
 // AdminSetUserBan 封禁 / 解封用户
 func (h *Handlers) AdminSetUserBan(c *gin.Context) {
 	id, ok := parseAdminUserID(c)
--- a/backend/handler/auth.go
+++ b/backend/handler/auth.go
@@ -382,8 +382,11 @@ func meUserBody(user *model.User, boardIDs []uint, badges []model.UserBadge) gin
 		"role":                user.Role,
 		"board_ids":           boardIDs,
 		"can_manage_messages": user.CanManageMessages,
-		"level":               user.Level,
-		"total_points":        user.TotalPoints,
+		// 生效权限码（角色默认 ∪ 账号级渠道授予）：前端据此渲染后台入口/按钮，
+		// 最终权限以后端 RequirePerm 校验为准
+		"perms":        service.EffectivePerms(user.Role, user.PermOverrides, user.CanManageMessages),
+		"level":        user.Level,
+		"total_points": user.TotalPoints,
 	}
 	if badges != nil {
 		body["badges"] = badges
--- a/backend/handler/board.go
+++ b/backend/handler/board.go
@@ -51,11 +51,11 @@ func (h *Handlers) BoardSidebar(c *gin.Context) {
 		}
 	}
 	c.JSON(http.StatusOK, gin.H{
-		"board":         data.Board,
-		"moderators":    data.Moderators,
-		"stats":         data.Stats,
-		"hot":           data.Hot,
-		"active_users":  data.ActiveUsers,
-		"checkin":       data.Checkin,
+		"board":        data.Board,
+		"moderators":   data.Moderators,
+		"stats":        data.Stats,
+		"hot":          data.Hot,
+		"active_users": data.ActiveUsers,
+		"checkin":      data.Checkin,
 	})
 }
--- a/backend/handler/chat.go
+++ b/backend/handler/chat.go
@@ -4,6 +4,8 @@ import (
 	"errors"
 	"net/http"
 	"strconv"
+	"strings"
+	"time"

 	"github.com/freefire/jiang13-bbs/middleware"
 	"github.com/freefire/jiang13-bbs/model"
@@ -42,6 +44,26 @@ func chatRoomID(c *gin.Context) (uint, bool) {
 	return uint(id), true
 }

+// formatMuteDurationCN 禁言时长中文格式化，供系统提示消息使用
+func formatMuteDurationCN(minutes int) string {
+	switch {
+	case minutes >= 30*24*60:
+		return "30 天"
+	case minutes >= 7*24*60:
+		return "7 天"
+	case minutes >= 3*24*60:
+		return "3 天"
+	case minutes >= 24*60:
+		return "1 天"
+	case minutes >= 12*60:
+		return "12 小时"
+	case minutes >= 60:
+		return "1 小时"
+	default:
+		return strconv.Itoa(minutes) + " 分钟"
+	}
+}
+
 func (h *Handlers) chatOversee(userID uint) bool {
 	actor, err := h.Auth.LoadActor(userID)
 	if err != nil || actor == nil {
@@ -219,11 +241,32 @@ func (h *Handlers) JoinChatRoom(c *gin.Context) {
 	if !ok {
 		return
 	}
-	_, _, err := h.Chat.Join(claims.ID, roomID)
+	member, joined, err := h.Chat.Join(claims.ID, roomID)
 	if err != nil {
 		c.JSON(chatErrToStatus(err), gin.H{"error": err.Error()})
 		return
 	}
+	// 首次加入则向房间广播系统提示 + 成员变更
+	if joined && member != nil {
+		displayName := h.Chat.DisplayName(claims.ID)
+		if displayName != "" {
+			sysMsg, _ := h.Chat.SendSystemMessage(roomID, displayName+" 加入了群聊")
+			if sysMsg != nil && sysMsg.ID > 0 {
+				h.Hub.BroadcastRoom(realtime.RoomChat(roomID), realtime.Envelope{
+					Type: realtime.EventChatMessage,
+					Data: sysMsg,
+				})
+			}
+		}
+		h.Hub.BroadcastRoom(realtime.RoomChat(roomID), realtime.Envelope{
+			Type: realtime.EventChatMembership,
+			Data: gin.H{
+				"room_id": roomID,
+				"status":  "joined",
+				"user_id": claims.ID,
+			},
+		})
+	}
 	c.JSON(http.StatusOK, gin.H{"ok": true})
 }

@@ -279,6 +322,35 @@ func (h *Handlers) InviteChatMembers(c *gin.Context) {
 			Data: gin.H{"room_id": roomID, "status": "invited"},
 		})
 	}
+	// 被邀请者入群时向房间广播系统提示 + 成员变更
+	if len(added) > 0 {
+		var names []string
+		for _, uid := range added {
+			if n := h.Chat.DisplayName(uid); n != "" {
+				names = append(names, n)
+			}
+		}
+		if len(names) > 0 {
+			content := strings.Join(names, "、") + " 加入了群聊"
+			sysMsg, _ := h.Chat.SendSystemMessage(roomID, content)
+			if sysMsg != nil && sysMsg.ID > 0 {
+				h.Hub.BroadcastRoom(realtime.RoomChat(roomID), realtime.Envelope{
+					Type: realtime.EventChatMessage,
+					Data: sysMsg,
+				})
+			}
+		}
+		for _, uid := range added {
+			h.Hub.BroadcastRoom(realtime.RoomChat(roomID), realtime.Envelope{
+				Type: realtime.EventChatMembership,
+				Data: gin.H{
+					"room_id": roomID,
+					"status":  "joined",
+					"user_id": uid,
+				},
+			})
+		}
+	}
 	c.JSON(http.StatusOK, gin.H{"added": added})
 }

@@ -322,7 +394,7 @@ func (h *Handlers) KickChatMember(c *gin.Context) {
 	c.JSON(http.StatusOK, gin.H{"ok": true})
 }

-// SetChatMemberMute 禁言/解禁成员
+// SetChatMemberMute 禁言/解禁成员；duration_minutes 可选：0/缺省=永久，>0=指定分钟数
 func (h *Handlers) SetChatMemberMute(c *gin.Context) {
 	claims := middleware.CurrentUser(c)
 	roomID, ok := chatRoomID(c)
@@ -335,17 +407,58 @@ func (h *Handlers) SetChatMemberMute(c *gin.Context) {
 		return
 	}
 	var body struct {
-		Muted bool `json:"muted"`
+		Muted           bool `json:"muted"`
+		DurationMinutes int  `json:"duration_minutes"`
 	}
 	if err := c.ShouldBindJSON(&body); err != nil {
 		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效"})
 		return
 	}
-	if err := h.Chat.SetMemberMute(claims.ID, roomID, uint(targetID), body.Muted, h.chatOversee(claims.ID)); err != nil {
+	duration := time.Duration(body.DurationMinutes) * time.Minute
+	targetName, err := h.Chat.SetMemberMute(claims.ID, roomID, uint(targetID), body.Muted, duration, h.chatOversee(claims.ID))
+	if err != nil {
 		c.JSON(chatErrToStatus(err), gin.H{"error": err.Error()})
 		return
 	}
-	c.JSON(http.StatusOK, gin.H{"ok": true, "muted": body.Muted})
+	// 向房间内广播禁言/解禁事件，客户端据此更新输入框状态与成员列表
+	var mutedUntil *time.Time
+	if body.Muted && body.DurationMinutes > 0 {
+		t := time.Now().Add(duration)
+		mutedUntil = &t
+	}
+	// 落库一条系统提示消息，刷新后仍可见（走 SendSystemMessage 统一处理房间 last_message_id 等）
+	var sysContent string
+	if body.Muted {
+		if body.DurationMinutes > 0 {
+			sysContent = targetName + " 已被禁言 " + formatMuteDurationCN(body.DurationMinutes)
+		} else {
+			sysContent = targetName + " 已被禁言 永久"
+		}
+	} else {
+		sysContent = targetName + " 的禁言已被解除"
+	}
+	sysMsg, _ := h.Chat.SendSystemMessage(roomID, sysContent)
+	// 广播系统消息到房间（sender_id=0，前端按系统消息渲染）；
+	// Data 与普通消息一致直接放消息体（扁平结构），前端按 room_id 匹配后才能即时上屏
+	if sysMsg != nil && sysMsg.ID > 0 {
+		h.Hub.BroadcastRoom(realtime.RoomChat(roomID), realtime.Envelope{
+			Type: realtime.EventChatMessage,
+			Data: sysMsg,
+		})
+	}
+	h.Hub.BroadcastRoom(realtime.RoomChat(roomID), realtime.Envelope{
+		Type: realtime.EventChatMemberMuted,
+		Data: gin.H{
+			"room_id":         roomID,
+			"user_id":         uint(targetID),
+			"muted":           body.Muted,
+			"muted_until":     mutedUntil,
+			"duration_minutes": body.DurationMinutes,
+			"target_name":     targetName,
+			"operator_id":     claims.ID,
+		},
+	})
+	c.JSON(http.StatusOK, gin.H{"ok": true, "muted": body.Muted, "duration_minutes": body.DurationMinutes})
 }

 // SetChatMemberRole 站长任命/撤销群管理员
@@ -619,7 +732,9 @@ func (h *Handlers) broadcastChatRecalled(roomID uint, msg *model.ChatMessage, ne
 	}
 	env := realtime.Envelope{Type: realtime.EventChatRecalled, Data: data}
 	h.Hub.BroadcastRoom(realtime.RoomChat(roomID), env)
-	// 未订阅该房间的成员（侧栏在看别的会话）也需要实时改预览
+	// 未订阅该房间的成员（侧栏在看别的会话）也需要实时改预览：
+	// 已撤回正文不得残留在侧栏预览里。预览回滚到上一条真实消息由 RecallMessage
+	// 回退 last_message_id 完成，本推送只负责即时抹掉正文、不产生角标与置顶。
 	if h.Chat == nil {
 		return
 	}
--- a/backend/handler/comment.go
+++ b/backend/handler/comment.go
@@ -82,38 +82,6 @@ func (h *Handlers) PostComments(c *gin.Context) {
 	})
 }

-// CommentLocation 评论定位：返回该评论的楼层号（含软删占位，与楼层分页口径一致），
-// 供通知/主页评论深链 #comment-{id} 跨页时换到正确页码。0 楼 = 评论不存在。
-func (h *Handlers) CommentLocation(c *gin.Context) {
-	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
-	if err != nil {
-		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的帖子 ID"})
-		return
-	}
-	cid, err := strconv.ParseUint(c.Param("cid"), 10, 64)
-	if err != nil {
-		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的评论 ID"})
-		return
-	}
-	// 待审/被拒帖子的评论不对公众开放
-	var viewerID uint
-	var loadActor func() *service.Actor
-	if claims := middleware.CurrentUser(c); claims != nil {
-		viewerID = claims.ID
-		loadActor = h.actorLoader(claims.ID)
-	}
-	if err := h.Post.EnsurePostVisible(uint(id), viewerID, loadActor); err != nil {
-		c.JSON(http.StatusNotFound, gin.H{"error": "帖子不存在"})
-		return
-	}
-	floor := h.Comment.FloorNumber(uint(id), uint(cid))
-	if floor <= 0 {
-		c.JSON(http.StatusNotFound, gin.H{"error": "评论不存在"})
-		return
-	}
-	c.JSON(http.StatusOK, gin.H{"floor": floor})
-}
-
 // CreateCommentRequest 评论请求
 type CreateCommentRequest struct {
 	Content  string `json:"content" binding:"required,min=1,max=5000"`
--- a/backend/handler/handlers.go
+++ b/backend/handler/handlers.go
@@ -10,38 +10,39 @@ import (

 // Handlers 聚合所有服务引用
 type Handlers struct {
-	Ops          *service.Operations
-	Cfg          *config.Config
-	Hub          *realtime.Hub
-	Auth         *service.AuthService
-	Board        *service.BoardService
-	Post         *service.PostService
-	Comment      *service.CommentService
-	Like         *service.LikeService
-	Favorite     *service.FavoriteService
-	Follow       *service.FollowService
-	Notification *service.NotificationService
-	OverviewSvc  *service.OverviewService
-	Checkin      *service.CheckinService
-	Announcement *service.AnnouncementService
-	SitePage     *service.SitePageService
-	Upload       *service.UploadService
-	PostFile     *service.PostFileService
-	Points       *service.PointsService
-	Setting      *service.SettingService
-	AdminUser    *service.AdminUserService
-	LegacyImport *service.LegacyImportService
-	Moderation   *service.ModerationService
-	Chat         *service.ChatService
-	Visit        *service.VisitStatsService
-	Analytics    *service.AnalyticsService
-	HidePwd      *service.HidePasswordCookie
-	Ads          *service.AdService
-	Sidebar      *service.SidebarService
-	FriendLink   *service.FriendLinkService
-	Badge        *service.BadgeService
+	Ops            *service.Operations
+	Cfg            *config.Config
+	Hub            *realtime.Hub
+	Auth           *service.AuthService
+	Board          *service.BoardService
+	Post           *service.PostService
+	Comment        *service.CommentService
+	Like           *service.LikeService
+	Favorite       *service.FavoriteService
+	Follow         *service.FollowService
+	Notification   *service.NotificationService
+	OverviewSvc    *service.OverviewService
+	Checkin        *service.CheckinService
+	Announcement   *service.AnnouncementService
+	SitePage       *service.SitePageService
+	Upload         *service.UploadService
+	PostFile       *service.PostFileService
+	Points         *service.PointsService
+	Setting        *service.SettingService
+	AdminUser      *service.AdminUserService
+	LegacyImport   *service.LegacyImportService
+	Moderation     *service.ModerationService
+	Chat           *service.ChatService
+	Visit          *service.VisitStatsService
+	Analytics      *service.AnalyticsService
+	HidePwd        *service.HidePasswordCookie
+	Ads            *service.AdService
+	Sidebar        *service.SidebarService
+	FriendLink     *service.FriendLinkService
+	Badge          *service.BadgeService
 	LeaderboardSvc *service.LeaderboardService
 	LibrarySvc     *service.LibraryService
+	SnippetSvc     *service.SnippetService
 }

 // resolvePublishStatus 决定新帖/新评的初始状态：
--- a/backend/handler/library.go
+++ b/backend/handler/library.go
@@ -4,6 +4,7 @@ import (
 	"errors"
 	"net/http"
 	"net/url"
+	"os"
 	"strconv"

 	"github.com/freefire/jiang13-bbs/middleware"
@@ -91,7 +92,11 @@ func (h *Handlers) AdminCreateLibraryDoc(c *gin.Context) {
 		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效"})
 		return
 	}
-	d, err := h.LibrarySvc.Create(&in)
+	var creatorID uint
+	if claims := middleware.CurrentUser(c); claims != nil {
+		creatorID = claims.ID
+	}
+	d, err := h.LibrarySvc.Create(&in, creatorID)
 	if err != nil {
 		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
 		return
@@ -242,6 +247,109 @@ func (h *Handlers) AdminDeleteLibraryFile(c *gin.Context) {
 	c.JSON(http.StatusOK, gin.H{"ok": true})
 }

+// ---------- 管理端：导出（迁移 / 备份） ----------
+
+// writeLibraryExport 装载完成后统一以附件形式流式下发 ZIP；
+// 注：一旦开始写响应体，中途 IO 错误无法再改成 JSON 错误，只能记录在 c.Errors。
+func (h *Handlers) writeLibraryExport(c *gin.Context, exp *service.LibraryExport) {
+	c.Header("Content-Type", "application/zip")
+	c.Header("Content-Disposition", "attachment; filename*=UTF-8''"+url.PathEscape(exp.Filename))
+	c.Header("X-Content-Type-Options", "nosniff")
+	c.Status(http.StatusOK)
+	if err := exp.WriteZip(c.Writer); err != nil {
+		_ = c.Error(err)
+	}
+}
+
+// AdminExportLibraryDoc 导出单本书（元信息 + 章节 + 附件 + 本地封面，ZIP）
+func (h *Handlers) AdminExportLibraryDoc(c *gin.Context) {
+	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的条目 ID"})
+		return
+	}
+	exp, err := h.LibrarySvc.BuildBookExport(uint(id))
+	if err != nil {
+		if errors.Is(err, service.ErrLibraryNotFound) {
+			c.JSON(http.StatusNotFound, gin.H{"error": "条目不存在"})
+			return
+		}
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "导出失败"})
+		return
+	}
+	h.writeLibraryExport(c, exp)
+}
+
+// AdminExportAllLibrary 导出全部在用书籍（单 ZIP，library.json 索引）
+func (h *Handlers) AdminExportAllLibrary(c *gin.Context) {
+	exp, err := h.LibrarySvc.BuildAllExport()
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "导出失败"})
+		return
+	}
+	h.writeLibraryExport(c, exp)
+}
+
+// AdminImportLibrary 上传导出 ZIP 恢复书籍（mode=create 默认跳过冲突 / overwrite 覆盖同名）
+func (h *Handlers) AdminImportLibrary(c *gin.Context) {
+	claims := middleware.CurrentUser(c)
+	if claims == nil {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "请先登录"})
+		return
+	}
+
+	const overhead = 64 << 10 // multipart 边界开销
+	limit := int64(service.LibraryImportMaxBytes) + overhead
+	if c.Request.ContentLength > limit {
+		c.JSON(http.StatusRequestEntityTooLarge, gin.H{"error": "导入包过大"})
+		return
+	}
+	c.Request.Body = http.MaxBytesReader(c.Writer, c.Request.Body, limit)
+
+	fh, err := c.FormFile("file")
+	if err != nil {
+		var maxErr *http.MaxBytesError
+		if errors.As(err, &maxErr) {
+			c.JSON(http.StatusRequestEntityTooLarge, gin.H{"error": "导入包过大（不能超过 512MB）"})
+			return
+		}
+		c.JSON(http.StatusBadRequest, gin.H{"error": "请选择书库导出的 ZIP 备份包"})
+		return
+	}
+	if fh.Size > service.LibraryImportMaxBytes {
+		c.JSON(http.StatusRequestEntityTooLarge, gin.H{"error": "导入包不能超过 512MB"})
+		return
+	}
+
+	mode := c.PostForm("mode")
+	if mode == "" {
+		mode = service.LibraryImportModeCreate
+	}
+
+	tmpPath, err := saveMultipartToTemp(fh, "library-import-*.zip")
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "读取导入包失败"})
+		return
+	}
+	defer os.Remove(tmpPath)
+
+	rep, err := h.LibrarySvc.ImportLibraryZip(tmpPath, mode, claims.ID)
+	if err != nil {
+		switch {
+		case errors.Is(err, service.ErrLibraryImportBadZip),
+			errors.Is(err, service.ErrLibraryImportFormat),
+			errors.Is(err, service.ErrLibraryImportVer),
+			errors.Is(err, service.ErrLibraryImportEmpty),
+			errors.Is(err, service.ErrLibraryImportMode):
+			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		default:
+			c.JSON(http.StatusInternalServerError, gin.H{"error": "导入失败：" + err.Error()})
+		}
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"report": rep})
+}
+
 // ---------- 管理端：章节 ----------

 // AdminCreateLibrarySection 新建章节（parent_id 空=章，非空=节）
--- a/backend/handler/notification.go
+++ b/backend/handler/notification.go
@@ -5,9 +5,18 @@ import (
 	"strconv"

 	"github.com/freefire/jiang13-bbs/middleware"
+	"github.com/freefire/jiang13-bbs/model"
 	"github.com/gin-gonic/gin"
 )

+// notificationView 通知列表项：附带关联评论的楼层相对锚点，
+// 供前端拼 #comment-{floor}（主楼）或 #comment-{floor}-r{comment_id}（楼中楼）。
+type notificationView struct {
+	*model.Notification
+	CommentFloor  uint `json:"comment_floor"`
+	CommentIsRoot bool `json:"comment_is_root"`
+}
+
 // Notifications 获取当前用户的通知列表（分页）
 func (h *Handlers) Notifications(c *gin.Context) {
 	claims := middleware.CurrentUser(c)
@@ -19,8 +28,24 @@ func (h *Handlers) Notifications(c *gin.Context) {
 		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
 		return
 	}
+	commentIDs := make([]uint, 0, len(list))
+	for _, n := range list {
+		if n.CommentID > 0 {
+			commentIDs = append(commentIDs, n.CommentID)
+		}
+	}
+	anchors := h.Comment.AnchorsByCommentIDs(commentIDs)
+	views := make([]notificationView, 0, len(list))
+	for i := range list {
+		v := notificationView{Notification: &list[i]}
+		if a, ok := anchors[list[i].CommentID]; ok {
+			v.CommentFloor = a.Floor
+			v.CommentIsRoot = a.IsRoot
+		}
+		views = append(views, v)
+	}
 	c.JSON(http.StatusOK, gin.H{
-		"notifications": nonNilSlice(list),
+		"notifications": nonNilSlice(views),
 		"total":         total,
 		"page":          page,
 		"size":          size,
--- a/backend/handler/operations.go
+++ b/backend/handler/operations.go
@@ -262,6 +262,10 @@ func (h *Handlers) SendEmailCode(c *gin.Context) {
 		return
 	}
 	wait, e := h.Ops.SendCode(req.Email, req.Purpose, c.ClientIP())
+	if errors.Is(e, service.ErrEmailRegistered) {
+		c.JSON(http.StatusBadRequest, gin.H{"error": e.Error()})
+		return
+	}
 	if !h.quotaResponse(c, wait, e) {
 		return
 	}
@@ -313,7 +317,8 @@ func (h *Handlers) PublicObject(c *gin.Context) {
 	defer r.Close()
 	c.Header("Content-Type", m)
 	c.Header("X-Content-Type-Options", "nosniff")
-	c.Header("Cache-Control", "private, no-store")
+	// 对象 ID 按上传随机生成不覆盖，直出内容可短缓存（302 预签名分支不缓存，防过期地址复用）
+	c.Header("Cache-Control", "public, max-age=86400")
 	c.Status(200)
 	_, _ = io.Copy(c.Writer, r)
 }
--- a/backend/handler/overview.go
+++ b/backend/handler/overview.go
@@ -29,20 +29,20 @@ func (h *Handlers) Overview(c *gin.Context) {
 		}
 	}
 	c.JSON(http.StatusOK, gin.H{
-		"stats":               data.Stats,
-		"hot":                 data.Hot,
-		"active_users":        data.ActiveUsers,
-		"boards":              data.Boards,
-		"announcements":       data.Announcements,
-		"announcements_total": data.AnnouncementsTotal,
-		"sidebar_pages":       data.SidebarPages,
-		"new_users":           data.NewUsers,
-		"checkin":             data.Checkin,
-		"ads":                 data.Ads,
-		"ads_panel_title":     data.AdsPanelTitle,
-		"ads_enabled":         data.AdsEnabled,
-		"sponsors":            data.Sponsors,
+		"stats":                data.Stats,
+		"hot":                  data.Hot,
+		"active_users":         data.ActiveUsers,
+		"boards":               data.Boards,
+		"announcements":        data.Announcements,
+		"announcements_total":  data.AnnouncementsTotal,
+		"sidebar_pages":        data.SidebarPages,
+		"new_users":            data.NewUsers,
+		"checkin":              data.Checkin,
+		"ads":                  data.Ads,
+		"ads_panel_title":      data.AdsPanelTitle,
+		"ads_enabled":          data.AdsEnabled,
+		"sponsors":             data.Sponsors,
 		"sponsors_panel_title": data.SponsorsPanelTitle,
-		"sponsors_enabled":    data.SponsorsEnabled,
+		"sponsors_enabled":     data.SponsorsEnabled,
 	})
 }
--- a/backend/handler/setting.go
+++ b/backend/handler/setting.go
@@ -57,6 +57,7 @@ type updateSettingsRequest struct {
 	BrandMark            *string               `json:"brand_mark"`
 	BrandLogoSize        *string               `json:"brand_logo_size"`
 	BrandLogoFit         *string               `json:"brand_logo_fit"`
+	BrandSloganVisible   *bool                 `json:"brand_slogan_visible"`
 	FooterLinks          *[]service.FooterLink `json:"footer_links"`

 	PointsCheckinBase     *int `json:"points_checkin_base"`
@@ -120,6 +121,7 @@ func settingsPayload(saved service.PublicSiteSettings) gin.H {
 		"brand_mark":             saved.BrandMark,
 		"brand_logo_size":        saved.BrandLogoSize,
 		"brand_logo_fit":         saved.BrandLogoFit,
+		"brand_slogan_visible":   saved.BrandSloganVisible,
 		"footer_links":           saved.FooterLinks,

 		"points_checkin_base":      saved.PointsCheckinBase,
@@ -160,6 +162,7 @@ func (req *updateSettingsRequest) hasAny() bool {
 		req.SiteWordmark != nil || req.SiteSlogan != nil || req.SiteKeywords != nil ||
 		req.LogoLightURL != nil || req.LogoDarkURL != nil || req.FaviconURL != nil ||
 		req.BrandMark != nil || req.BrandLogoSize != nil || req.BrandLogoFit != nil ||
+		req.BrandSloganVisible != nil ||
 		req.FooterLinks != nil ||
 		req.PointsCheckinBase != nil || req.PointsStreakEveryDays != nil || req.PointsStreakBonus != nil ||
 		req.PointsPostReward != nil || req.PointsPostDailyCap != nil ||
@@ -540,6 +543,12 @@ func (h *Handlers) UpdateSettings(c *gin.Context) {
 			return
 		}
 	}
+	if req.BrandSloganVisible != nil {
+		if err := h.Setting.SetBrandSloganVisible(*req.BrandSloganVisible); err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": "保存站点设置失败"})
+			return
+		}
+	}
 	if req.FooterLinks != nil {
 		if err := h.Setting.SetFooterLinks(*req.FooterLinks); err != nil {
 			if errors.Is(err, service.ErrInvalidSiteSetting) {
--- a/backend/handler/snippet.go
+++ b/backend/handler/snippet.go
@@ -0,0 +1,424 @@
+package handler
+
+import (
+	"errors"
+	"net/http"
+	"strconv"
+
+	"github.com/freefire/jiang13-bbs/middleware"
+	"github.com/freefire/jiang13-bbs/model"
+	"github.com/freefire/jiang13-bbs/service"
+	"github.com/gin-gonic/gin"
+)
+
+// snippetError 统一错误映射
+func snippetError(c *gin.Context, err error) {
+	switch {
+	case errors.Is(err, service.ErrSnippetNotFound):
+		c.JSON(http.StatusNotFound, gin.H{"error": "代码片段不存在"})
+	case errors.Is(err, service.ErrSnippetForbidden):
+		c.JSON(http.StatusForbidden, gin.H{"error": "无权操作该代码片段"})
+	case errors.Is(err, service.ErrSnippetBadInput):
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+	case errors.Is(err, service.ErrCommentNotFound):
+		c.JSON(http.StatusNotFound, gin.H{"error": "评论不存在"})
+	case errors.Is(err, service.ErrCommentForbidden):
+		c.JSON(http.StatusForbidden, gin.H{"error": "无权操作该评论"})
+	default:
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "服务器错误"})
+	}
+}
+
+// SnippetList 公开片段广场
+func (h *Handlers) SnippetList(c *gin.Context) {
+	q := c.Query("q")
+	lang := c.Query("lang")
+	sort := c.Query("sort")
+	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
+	size, _ := strconv.Atoi(c.DefaultQuery("size", "12"))
+	items, total, err := h.SnippetSvc.ListPublic(q, lang, sort, page, size)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "获取片段列表失败"})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"items": nonNilSlice(items), "total": total})
+}
+
+// SnippetLanguages 语言白名单
+func (h *Handlers) SnippetLanguages(c *gin.Context) {
+	c.JSON(http.StatusOK, gin.H{"languages": service.SnippetLanguages()})
+}
+
+// SnippetStats 广场聚合统计
+func (h *Handlers) SnippetStats(c *gin.Context) {
+	stats, err := h.SnippetSvc.Stats()
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "获取统计失败"})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"stats": stats})
+}
+
+// SnippetDetail 公开片段详情
+func (h *Handlers) SnippetDetail(c *gin.Context) {
+	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的片段 ID"})
+		return
+	}
+	var viewerID uint
+	if claims := middleware.CurrentUser(c); claims != nil {
+		viewerID = claims.ID
+	}
+	isStaff := h.isStaff(c)
+	detail, err := h.SnippetSvc.GetPublic(uint(id), viewerID, isStaff)
+	if err != nil {
+		snippetError(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"snippet": detail})
+}
+
+// SnippetMine 我的片段列表
+func (h *Handlers) SnippetMine(c *gin.Context) {
+	claims := middleware.CurrentUser(c)
+	if claims == nil {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "请先登录"})
+		return
+	}
+	q := c.Query("q")
+	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
+	size, _ := strconv.Atoi(c.DefaultQuery("size", "12"))
+	items, total, err := h.SnippetSvc.ListMine(claims.ID, q, page, size)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "获取片段列表失败"})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"items": nonNilSlice(items), "total": total})
+}
+
+// SnippetCreate 创建片段
+func (h *Handlers) SnippetCreate(c *gin.Context) {
+	claims := middleware.CurrentUser(c)
+	if claims == nil {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "请先登录"})
+		return
+	}
+	var in service.SnippetInput
+	if err := c.ShouldBindJSON(&in); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效"})
+		return
+	}
+	snippet, err := h.SnippetSvc.Create(&in, claims.ID)
+	if err != nil {
+		snippetError(c, err)
+		return
+	}
+	c.JSON(http.StatusCreated, gin.H{"snippet": snippet})
+}
+
+// SnippetUpdate 更新片段
+func (h *Handlers) SnippetUpdate(c *gin.Context) {
+	claims := middleware.CurrentUser(c)
+	if claims == nil {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "请先登录"})
+		return
+	}
+	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的片段 ID"})
+		return
+	}
+	var in service.SnippetInput
+	if err := c.ShouldBindJSON(&in); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效"})
+		return
+	}
+	snippet, err := h.SnippetSvc.Update(uint(id), &in, claims.ID, h.isStaff(c))
+	if err != nil {
+		snippetError(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"snippet": snippet})
+}
+
+// SnippetDelete 删除片段（owner 或 staff）
+func (h *Handlers) SnippetDelete(c *gin.Context) {
+	claims := middleware.CurrentUser(c)
+	if claims == nil {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "请先登录"})
+		return
+	}
+	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的片段 ID"})
+		return
+	}
+	if err := h.SnippetSvc.Delete(uint(id), claims.ID, h.isStaff(c)); err != nil {
+		snippetError(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"ok": true})
+}
+
+// SnippetFork Fork 公开片段
+func (h *Handlers) SnippetFork(c *gin.Context) {
+	claims := middleware.CurrentUser(c)
+	if claims == nil {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "请先登录"})
+		return
+	}
+	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的片段 ID"})
+		return
+	}
+	snippet, err := h.SnippetSvc.Fork(uint(id), claims.ID)
+	if err != nil {
+		snippetError(c, err)
+		return
+	}
+	c.JSON(http.StatusCreated, gin.H{"snippet": snippet})
+}
+
+// SnippetCopy 记录复制（节流由 service 内部处理）
+func (h *Handlers) SnippetCopy(c *gin.Context) {
+	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的片段 ID"})
+		return
+	}
+	key := c.ClientIP()
+	if claims := middleware.CurrentUser(c); claims != nil {
+		key = "user:" + strconv.FormatUint(uint64(claims.ID), 10)
+	}
+	if err := h.SnippetSvc.RecordCopy(uint(id), key); err != nil {
+		snippetError(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"ok": true})
+}
+
+// SnippetHistory 片段编辑历史
+func (h *Handlers) SnippetHistory(c *gin.Context) {
+	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的片段 ID"})
+		return
+	}
+	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
+	size, _ := strconv.Atoi(c.DefaultQuery("size", "10"))
+	items, total, err := h.SnippetSvc.ListHistory(uint(id), page, size)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "获取历史失败"})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"items": nonNilSlice(items), "total": total})
+}
+
+// SnippetForks 公开 fork 列表
+func (h *Handlers) SnippetForks(c *gin.Context) {
+	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的片段 ID"})
+		return
+	}
+	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
+	size, _ := strconv.Atoi(c.DefaultQuery("size", "12"))
+	items, total, err := h.SnippetSvc.ListForks(uint(id), page, size)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "获取 Fork 列表失败"})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"items": nonNilSlice(items), "total": total})
+}
+
+// SnippetComments 片段评论列表
+func (h *Handlers) SnippetComments(c *gin.Context) {
+	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的片段 ID"})
+		return
+	}
+	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
+	size, _ := strconv.Atoi(c.DefaultQuery("size", "20"))
+	items, total, err := h.SnippetSvc.ListComments(uint(id), page, size)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "获取评论失败"})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"items": nonNilSlice(items), "total": total})
+}
+
+// SnippetCommentCreate 创建片段评论
+func (h *Handlers) SnippetCommentCreate(c *gin.Context) {
+	claims := middleware.CurrentUser(c)
+	if claims == nil {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "请先登录"})
+		return
+	}
+	snippetID, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的片段 ID"})
+		return
+	}
+	var in struct {
+		Content  string `json:"content"`
+		ParentID *uint  `json:"parent_id"`
+	}
+	if err := c.ShouldBindJSON(&in); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效"})
+		return
+	}
+	comment, err := h.SnippetSvc.CreateComment(claims.ID, uint(snippetID), in.Content, in.ParentID)
+	if err != nil {
+		snippetError(c, err)
+		return
+	}
+	c.JSON(http.StatusCreated, gin.H{"comment": comment})
+}
+
+// SnippetCommentUpdate 更新片段评论
+func (h *Handlers) SnippetCommentUpdate(c *gin.Context) {
+	claims := middleware.CurrentUser(c)
+	if claims == nil {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "请先登录"})
+		return
+	}
+	cid, err := strconv.ParseUint(c.Param("cid"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的评论 ID"})
+		return
+	}
+	var in struct {
+		Content string `json:"content"`
+	}
+	if err := c.ShouldBindJSON(&in); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效"})
+		return
+	}
+	comment, err := h.SnippetSvc.UpdateComment(uint(cid), claims.ID, in.Content)
+	if err != nil {
+		snippetError(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"comment": comment})
+}
+
+// SnippetCommentDelete 删除片段评论
+func (h *Handlers) SnippetCommentDelete(c *gin.Context) {
+	claims := middleware.CurrentUser(c)
+	if claims == nil {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "请先登录"})
+		return
+	}
+	cid, err := strconv.ParseUint(c.Param("cid"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的评论 ID"})
+		return
+	}
+	if err := h.SnippetSvc.DeleteComment(uint(cid), claims.ID, h.isStaff(c)); err != nil {
+		snippetError(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"ok": true})
+}
+
+// SnippetCommentHistory 片段评论编辑历史（登录即可见；分页）
+func (h *Handlers) SnippetCommentHistory(c *gin.Context) {
+	claims := middleware.CurrentUser(c)
+	cid, err := strconv.ParseUint(c.Param("cid"), 10, 64)
+	if err != nil || cid == 0 {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的评论 ID"})
+		return
+	}
+	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
+	size, _ := strconv.Atoi(c.DefaultQuery("size", "10"))
+	items, total, err := h.SnippetSvc.ListCommentHistory(h.loadActor(claims.ID), uint(cid), page, size)
+	if err != nil {
+		switch {
+		case errors.Is(err, service.ErrCommentNotFound):
+			c.JSON(http.StatusNotFound, gin.H{"error": err.Error()})
+		case errors.Is(err, service.ErrCommentForbidden):
+			c.JSON(http.StatusForbidden, gin.H{"error": err.Error()})
+		default:
+			c.JSON(http.StatusInternalServerError, gin.H{"error": "获取编辑历史失败"})
+		}
+		return
+	}
+	if page < 1 {
+		page = 1
+	}
+	if size < 1 || size > 50 {
+		size = 10
+	}
+	c.JSON(http.StatusOK, gin.H{
+		"items": items,
+		"total": total,
+		"page":  page,
+		"size":  size,
+	})
+}
+
+// AdminSnippetList 管理端片段列表
+func (h *Handlers) AdminSnippetList(c *gin.Context) {
+	q := c.Query("q")
+	visibility := c.Query("visibility")
+	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
+	size, _ := strconv.Atoi(c.DefaultQuery("size", "20"))
+	items, total, err := h.SnippetSvc.AdminList(q, visibility, page, size)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "获取片段列表失败"})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"items": nonNilSlice(items), "total": total})
+}
+
+// AdminSnippetDelete 管理端软删片段
+func (h *Handlers) AdminSnippetDelete(c *gin.Context) {
+	claims := middleware.CurrentUser(c)
+	if claims == nil {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "请先登录"})
+		return
+	}
+	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的片段 ID"})
+		return
+	}
+	if err := h.SnippetSvc.AdminDelete(uint(id), claims.ID); err != nil {
+		snippetError(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"ok": true})
+}
+
+// AdminSnippetSetVisibility 管理端强制修改可见性
+func (h *Handlers) AdminSnippetSetVisibility(c *gin.Context) {
+	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的片段 ID"})
+		return
+	}
+	var in struct {
+		Visibility string `json:"visibility"`
+	}
+	if err := c.ShouldBindJSON(&in); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效"})
+		return
+	}
+	if err := h.SnippetSvc.AdminSetVisibility(uint(id), in.Visibility); err != nil {
+		snippetError(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"ok": true})
+}
+
+// isStaff 判断当前用户是否为管理角色
+func (h *Handlers) isStaff(c *gin.Context) bool {
+	claims := middleware.CurrentUser(c)
+	if claims == nil {
+		return false
+	}
+	return model.IsStaff(model.Role(claims.Role))
+}
--- a/backend/handler/upload.go
+++ b/backend/handler/upload.go
@@ -10,6 +10,7 @@ import (
 	"time"

 	"github.com/freefire/jiang13-bbs/middleware"
+	"github.com/freefire/jiang13-bbs/model"
 	"github.com/freefire/jiang13-bbs/service"
 	"github.com/gin-gonic/gin"
 )
@@ -102,7 +103,7 @@ func (h *Handlers) UploadImage(c *gin.Context) {
 	}
 	defer f.Close()

-	att, err := h.Upload.SaveImage(claims.ID, f)
+	att, err := h.Upload.SaveImage(claims.ID, f, c.PostForm("source"))
 	if err != nil {
 		var maxErr *http.MaxBytesError
 		if errors.As(err, &maxErr) {
@@ -314,7 +315,9 @@ func (h *Handlers) UploadBrandFromMedia(c *gin.Context) {
 	c.JSON(http.StatusOK, gin.H{"url": url})
 }

-// UploadLibraryCoverFromMedia 把本人媒体库图片复制一份作书籍封面素材，只返回 URL，不绑定条目
+// UploadLibraryCoverFromMedia 把本人媒体库图片用作书籍封面素材。
+// 若该图已是封面类型（source=library_cover），直接复用原记录，不再复制；
+// 否则复制一份并标记为封面类型（与原图解耦，删除原图不影响封面）。
 func (h *Handlers) UploadLibraryCoverFromMedia(c *gin.Context) {
 	var req struct {
 		AttachmentID uint `json:"attachment_id"`
@@ -328,7 +331,14 @@ func (h *Handlers) UploadLibraryCoverFromMedia(c *gin.Context) {
 		c.JSON(http.StatusUnauthorized, gin.H{"error": "请先登录"})
 		return
 	}
-	att, err := h.Upload.CopyImageFromMedia(claims.ID, req.AttachmentID)
+
+	// 已是封面类型的图直接复用，避免重复复制产生冗余记录
+	if existing, err := h.Upload.FindMediaBySource(claims.ID, req.AttachmentID, model.AttachmentSourceLibraryCover); err == nil {
+		c.JSON(http.StatusOK, gin.H{"url": existing.URL, "attachment": existing})
+		return
+	}
+
+	att, err := h.Upload.CopyImageFromMedia(claims.ID, req.AttachmentID, model.AttachmentSourceLibraryCover)
 	if err != nil {
 		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
 		return
@@ -404,6 +414,23 @@ func (h *Handlers) MediaLibraryThumb(c *gin.Context) {
 	c.Data(http.StatusOK, "image/webp", data)
 }

+// ImageVariant 公开图片变体（GET /api/img?u=<源图URL>&w=<白名单宽度>）：
+// 供全站 srcset 消费，源内容不可变 → immutable 长缓存；失败 404 由前端 onError 兜底
+func (h *Handlers) ImageVariant(c *gin.Context) {
+	w, err := strconv.Atoi(c.Query("w"))
+	if err != nil || !service.IsVariantWidth(w) {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "不支持的尺寸"})
+		return
+	}
+	data, m, err := h.Upload.Variant(c.Query("u"), w)
+	if err != nil {
+		c.JSON(http.StatusNotFound, gin.H{"error": "图片不可用"})
+		return
+	}
+	c.Header("Cache-Control", "public, max-age=31536000, immutable")
+	c.Data(http.StatusOK, m, data)
+}
+
 func brandTooLarge(slot string) string {
 	if slot == service.BrandSlotFavicon {
 		return "Favicon 不能超过 512KB"
--- a/backend/handler/user.go
+++ b/backend/handler/user.go
@@ -144,11 +144,11 @@ func (h *Handlers) UserProfile(c *gin.Context) {
 	c.JSON(http.StatusOK, gin.H{
 		"user": userPayload,
 		"stats": gin.H{
-			"post_count":     postCount,
-			"comment_count":  commentCount,
-			"points":         pointsTotal,
-			"streak":         streak,
-			"favorite_count": favoriteCount,
+			"post_count":      postCount,
+			"comment_count":   commentCount,
+			"points":          pointsTotal,
+			"streak":          streak,
+			"favorite_count":  favoriteCount,
 			"following_count": followingCount,
 		},
 		"posts":       nonNilSlice(posts),
--- a/backend/middleware/auth.go
+++ b/backend/middleware/auth.go
@@ -85,7 +85,32 @@ func (m *AuthMiddleware) RequireStaff() gin.HandlerFunc {
 	}
 }

-// RequirePerm 功能点鉴权，必须接在 RequireStaff 之后
+// RequireActor 必须登录并加载实时 Actor（不要求管理角色），
+// 供账号级渠道权限（非管理角色也可被单独授予）所在路由组使用；
+// 功能点鉴权由后续 RequirePerm 完成
+func (m *AuthMiddleware) RequireActor() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		claims, ok := m.parseToken(c)
+		if !ok {
+			if c.GetBool(AccountBannedKey) {
+				bannedJSON(c)
+				return
+			}
+			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "未登录"})
+			return
+		}
+		actor, err := m.auth.LoadActor(claims.ID)
+		if err != nil {
+			c.AbortWithStatusJSON(http.StatusForbidden, gin.H{"error": "无权限执行该操作"})
+			return
+		}
+		c.Set("user", claims)
+		c.Set(ActorKey, actor)
+		c.Next()
+	}
+}
+
+// RequirePerm 功能点鉴权，必须接在 RequireStaff / RequireActor 之后
 func (m *AuthMiddleware) RequirePerm(perm string) gin.HandlerFunc {
 	return func(c *gin.Context) {
 		actor := CurrentActor(c)
--- a/backend/middleware/upload_cache.go
+++ b/backend/middleware/upload_cache.go
@@ -0,0 +1,19 @@
+package middleware
+
+import (
+	"strings"
+
+	"github.com/gin-gonic/gin"
+)
+
+// UploadStaticCache 上传文件长缓存：/uploads 下文件名均为上传时随机生成、
+// 写入后不覆盖（SaveAvatar/SaveImage 等均新建文件），URL 内容恒定，可安全
+// immutable。PageSpeed「缓存生命周期」修复项。
+func UploadStaticCache() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		if strings.HasPrefix(c.Request.URL.Path, "/uploads/") {
+			c.Header("Cache-Control", "public, max-age=31536000, immutable")
+		}
+		c.Next()
+	}
+}
--- a/backend/model/ad.go
+++ b/backend/model/ad.go
@@ -19,26 +19,26 @@ const (

 // Ad 赞助广告（游客可申购，管理员审核后展示于首页侧栏）
 type Ad struct {
-	ID            uint           `gorm:"primaryKey" json:"id"`
-	Kind          string         `gorm:"size:16;not null;index" json:"kind"`     // image | text
-	Status        string         `gorm:"size:16;not null;index" json:"status"`   // pending/active/rejected/expired
-	ContactEmail  string         `gorm:"size:128;not null" json:"contact_email"`
-	LinkURL       string         `gorm:"size:512;not null" json:"link_url"`
-	ImageURL      string         `gorm:"size:512" json:"image_url"` // 图片广告
-	Title         string         `gorm:"size:64" json:"title"`      // 文字广告
-	TextColor     string         `gorm:"size:16" json:"text_color"`
-	BgColor       string         `gorm:"size:16" json:"bg_color"`
-	DurationDays  int            `gorm:"not null" json:"duration_days"`
-	PaymentID     string         `gorm:"size:64;not null" json:"payment_id"`
-	BuyerNote     string         `gorm:"size:200" json:"buyer_note"`
-	StartsAt      *time.Time     `json:"starts_at"`
-	EndsAt        *time.Time     `json:"ends_at"`
-	RejectReason  string         `gorm:"size:200" json:"reject_reason"`
-	SortOrder     int            `gorm:"not null;default:0" json:"sort_order"`
-	SubmitIP      string         `gorm:"size:45" json:"-"`
-	ReviewedAt    *time.Time     `json:"reviewed_at"`
-	ReviewedBy    *uint          `json:"reviewed_by"`
-	CreatedAt     time.Time      `json:"created_at"`
-	UpdatedAt     time.Time      `json:"updated_at"`
-	DeletedAt     gorm.DeletedAt `gorm:"index" json:"-"`
+	ID           uint           `gorm:"primaryKey" json:"id"`
+	Kind         string         `gorm:"size:16;not null;index" json:"kind"`   // image | text
+	Status       string         `gorm:"size:16;not null;index" json:"status"` // pending/active/rejected/expired
+	ContactEmail string         `gorm:"size:128;not null" json:"contact_email"`
+	LinkURL      string         `gorm:"size:512;not null" json:"link_url"`
+	ImageURL     string         `gorm:"size:512" json:"image_url"` // 图片广告
+	Title        string         `gorm:"size:64" json:"title"`      // 文字广告
+	TextColor    string         `gorm:"size:16" json:"text_color"`
+	BgColor      string         `gorm:"size:16" json:"bg_color"`
+	DurationDays int            `gorm:"not null" json:"duration_days"`
+	PaymentID    string         `gorm:"size:64;not null" json:"payment_id"`
+	BuyerNote    string         `gorm:"size:200" json:"buyer_note"`
+	StartsAt     *time.Time     `json:"starts_at"`
+	EndsAt       *time.Time     `json:"ends_at"`
+	RejectReason string         `gorm:"size:200" json:"reject_reason"`
+	SortOrder    int            `gorm:"not null;default:0" json:"sort_order"`
+	SubmitIP     string         `gorm:"size:45" json:"-"`
+	ReviewedAt   *time.Time     `json:"reviewed_at"`
+	ReviewedBy   *uint          `json:"reviewed_by"`
+	CreatedAt    time.Time      `json:"created_at"`
+	UpdatedAt    time.Time      `json:"updated_at"`
+	DeletedAt    gorm.DeletedAt `gorm:"index" json:"-"`
 }
--- a/backend/model/db.go
+++ b/backend/model/db.go
@@ -56,7 +56,7 @@ func InitDB(dsn string) error {
 	}

 	if err := db.AutoMigrate(
-		&TemporaryUpload{}, &ModuleConfig{}, &SettingsAudit{}, &ActionCounter{}, &MailTask{}, &EmailChallenge{}, &StoredObject{},
+		&TemporaryUpload{}, &ModuleConfig{}, &SettingsAudit{}, &ActionCounter{}, &MailTask{}, &EmailChallenge{}, &StoredObject{}, &Blob{},
 		&User{}, &Board{}, &Post{}, &PostEditHistory{}, &Comment{}, &CommentEditHistory{}, &RefreshToken{}, &Like{}, &Favorite{}, &Follow{}, &Notification{}, &Checkin{},
 		&Announcement{}, &SitePage{}, &SiteSetting{}, &SiteDailyStats{}, &SiteDailyVisitor{}, &VisitEvent{}, &Attachment{}, &UserBoard{}, &LoginLog{},
 		&ChatRoom{}, &ChatRoomMember{}, &ChatMessage{},
@@ -64,6 +64,7 @@ func InitDB(dsn string) error {
 		&Badge{}, &UserBadge{},
 		&PostPollVote{}, &PostLotteryEntry{}, &Ad{}, &SidebarWidget{}, &FriendLink{},
 		&ImportRecord{}, &LibraryDoc{}, &LibraryFile{}, &LibrarySection{},
+		&CodeSnippet{}, &SnippetVersion{}, &SnippetComment{}, &SnippetCommentEditHistory{},
 	); err != nil {
 		return fmt.Errorf("自动迁移失败: %w", err)
 	}
@@ -78,6 +79,9 @@ func InitDB(dsn string) error {
 	// 每次启动执行，幂等自愈，保证与 CreditTx 增量口径一致（均排除 bounty_refund）
 	backfillUserTotalPoints(db)

+	// 书库：历史条目 creator_id=0 时介绍页无创建者可展示，回填为站长
+	backfillLibraryCreator(db)
+
 	// login_logs.success 早期 default=true 与 GORM 零值省略叠加，
 	// 会把失败登录错存为成功；AutoMigrate 不会改列默认值，这里幂等修正
 	if err := db.Exec(`ALTER TABLE login_logs ALTER COLUMN success SET DEFAULT false`).Error; err != nil {
@@ -146,6 +150,7 @@ func dropStaleChatFKConstraints(db *gorm.DB) error {
 	pairs := []struct{ table, constraint string }{
 		{"chat_rooms", "fk_chat_rooms_last_message"},
 		{"notifications", "fk_notifications_room"},
+		{"chat_messages", "fk_chat_messages_sender"},
 	}
 	for _, p := range pairs {
 		db.Exec(fmt.Sprintf(`ALTER TABLE IF EXISTS %s DROP CONSTRAINT IF EXISTS %s`, p.table, p.constraint))
@@ -368,6 +373,29 @@ func backfillUserTotalPoints(db *gorm.DB) {
 	}
 }

+// backfillLibraryCreator 为历史书库条目（creator_id=0，特性上线前创建或早期导入）
+// 回填站长为创建者，保证介绍页「创建者」可展示。幂等：仅影响 creator_id=0 的行；
+// 站长不存在（空库）时跳过，等下次启动自愈。
+func backfillLibraryCreator(db *gorm.DB) {
+	var owner User
+	err := db.Select("id").Where("role = ?", RoleOwner).Order("id ASC").First(&owner).Error
+	if errors.Is(err, gorm.ErrRecordNotFound) {
+		return
+	}
+	if err != nil {
+		log.Printf("[model] 回填书库创建者前置查询失败: %v", err)
+		return
+	}
+	res := db.Exec(`UPDATE library_docs SET creator_id = ? WHERE creator_id = 0`, owner.ID)
+	if res.Error != nil {
+		log.Printf("[model] 回填书库创建者失败: %v", res.Error)
+		return
+	}
+	if res.RowsAffected > 0 {
+		log.Printf("[model] 已回填书库条目创建者为站长 %d 行", res.RowsAffected)
+	}
+}
+
 // backfillBoardDefaults 为升级前已存在的板块补齐新字段默认值。
 // 以 post_policy 为空作为「迁移前旧行」的判定标志：仅对这些行一次性回填
 // post_policy=all、visible=true；后续已被显式设置过的行（含站长隐藏的板块）不会被覆盖。
--- a/backend/model/models.go
+++ b/backend/model/models.go
@@ -122,6 +122,7 @@ type User struct {
 	Role              Role           `gorm:"size:16;default:user" json:"role"`
 	Banned            bool           `gorm:"default:false" json:"banned"`
 	CanManageMessages bool           `gorm:"not null;default:false" json:"can_manage_messages"` // 站点消息管理（仅站长可授；站长/超管固有全站监管）
+	PermOverrides     string         `gorm:"size:256;default:''" json:"-"`                      // 账号级渠道权限覆盖 JSON；仅后台权限服务读取，序列化跳过
 	Points            int            `gorm:"not null;default:0" json:"points"`                  // 可用积分余额
 	TotalPoints       int            `gorm:"not null;default:0" json:"total_points"`            // 累计获得积分（经验值，定级依据；消费不减）
 	Level             int            `gorm:"-" json:"level"`                                    // 用户等级（AfterFind 由 TotalPoints 计算，纯展示不入库）
@@ -323,9 +324,9 @@ const (
 	PointReasonBountyEscrow   = "bounty_escrow"
 	PointReasonBountyRefund   = "bounty_refund"
 	PointReasonBountyAward    = "bounty_award"
-	PointReasonPostReward     = "post_reward"  // 发帖奖励（可配置，0=关闭）
-	PointReasonReplyReward    = "reply_reward" // 回复奖励（可配置，0=关闭）
-	PointReasonStreakBonus    = "streak_bonus" // 连续签到里程碑加成
+	PointReasonPostReward     = "post_reward"      // 发帖奖励（可配置，0=关闭）
+	PointReasonReplyReward    = "reply_reward"     // 回复奖励（可配置，0=关闭）
+	PointReasonStreakBonus    = "streak_bonus"     // 连续签到里程碑加成
 	PointReasonRecommend      = "recommend_reward" // 帖子被推荐奖励（可配置，0=关闭，每帖仅一次）
 	PointReasonAdminAdjust    = "admin_adjust"     // 管理员手动调整（加分计累计可升级；扣分仅扣余额）
 	PointReasonNecroReply     = "necro_reply"      // 旧帖回复扣分（可配置，0=关闭）
@@ -361,12 +362,13 @@ type PostContentUnlock struct {

 // PostAttachment 帖子文件附件（不走公开静态目录，经 API 鉴权下载）
 type PostAttachment struct {
-	ObjectID      string         `gorm:"size:64;index" json:"-"`
+	ObjectID      string         `gorm:"size:96;index" json:"-"`
 	ID            uint           `gorm:"primaryKey" json:"id"`
 	PostID        uint           `gorm:"index;not null;default:0" json:"post_id"` // 0=草稿未绑定
 	UserID        uint           `gorm:"index;not null" json:"user_id"`
-	Name          string         `gorm:"size:256;not null" json:"name"` // 原始文件名
-	StoredName    string         `gorm:"size:64;not null" json:"-"`     // 磁盘文件名
+	Name          string         `gorm:"size:256;not null" json:"name"`              // 原始文件名
+	StoredName    string         `gorm:"size:64;not null" json:"-"`                  // 磁盘文件名（blob 去重后即内容 hash）
+	BlobHash      string         `gorm:"size:64;not null;default:'';index" json:"-"` // 内容寻址 hash；空=历史文件，不走引用计数
 	MIME          string         `gorm:"size:128;not null;default:application/octet-stream" json:"mime"`
 	Size          int            `gorm:"not null;default:0" json:"size"`
 	PricePoints   int            `gorm:"not null;default:0" json:"price_points"` // 0=免费
@@ -486,7 +488,7 @@ type Notification struct {
 	IsRead    bool      `gorm:"default:false;index" json:"is_read"`
 	CreatedAt time.Time `json:"created_at"`

-	Actor User      `gorm:"foreignKey:ActorID" json:"actor,omitempty"`
+	Actor User `gorm:"foreignKey:ActorID" json:"actor,omitempty"`
 	// PostID 允许为 0（mention/badge 等无关联帖子），禁建 FK 约束，否则 post_id=0 插入违反外键
 	Post Post      `gorm:"foreignKey:PostID;constraint:-" json:"post,omitempty"`
 	Room *ChatRoom `gorm:"foreignKey:RoomID;constraint:-" json:"room,omitempty"`
@@ -524,19 +526,25 @@ type SitePage struct {

 // LibraryDoc 书库条目（书籍/文档/纯 HTML 页展示；文件独立目录存储，仅经 API 消费）
 type LibraryDoc struct {
-	ID          uint           `gorm:"primaryKey" json:"id"`
-	Slug        string         `gorm:"size:64;uniqueIndex;not null" json:"slug"`
-	Title       string         `gorm:"size:200;not null" json:"title"`
-	Description string         `gorm:"type:text" json:"description"` // markdown 介绍，可空
-	CoverURL    string         `gorm:"size:512" json:"cover_url"`    // 可选图片封面（/uploads/images）
-	Published   bool           `gorm:"not null;index" json:"published"`
-	SortOrder   int            `gorm:"not null;default:0" json:"sort_order"`
+	ID          uint   `gorm:"primaryKey" json:"id"`
+	Slug        string `gorm:"size:64;uniqueIndex;not null" json:"slug"`
+	Title       string `gorm:"size:200;not null" json:"title"`
+	Description string `gorm:"type:text" json:"description"`           // markdown 介绍，可空
+	CoverURL    string `gorm:"size:512" json:"cover_url"`              // 可选图片封面（/uploads/images）
+	CoverWidth  int    `gorm:"not null;default:0" json:"cover_width"`  // 封面自然宽（0=未知，前端回退探测）
+	CoverHeight int    `gorm:"not null;default:0" json:"cover_height"` // 封面自然高（0=未知，前端回退探测）
+	Published   bool   `gorm:"not null;index" json:"published"`
+	SortOrder   int    `gorm:"not null;default:0" json:"sort_order"`
 	// EntriesAuto 全章节条目卡模式：开启后章节内容免写 [entries] 壳，
 	// 「## 标题 + @tags/@summary/字段::值/@source 指令行」自动识别为条目卡（个别章节用 [entries:off] 例外）
 	EntriesAuto bool `gorm:"not null;default:false" json:"entries_auto"`
-	CreatedAt   time.Time      `json:"created_at"`
-	UpdatedAt   time.Time      `json:"updated_at"`
-	DeletedAt   gorm.DeletedAt `gorm:"index" json:"-"`
+	// Author 书籍作者（自由文本，可填多位，如「鲁迅 译 / 某某注」），仅展示用
+	Author string `gorm:"size:100;not null;default:''" json:"author"`
+	// CreatorID 条目创建者（站点用户；0=历史数据或导入时无对应用户），创建后不变
+	CreatorID uint           `gorm:"index;not null;default:0" json:"creator_id"`
+	CreatedAt time.Time      `json:"created_at"`
+	UpdatedAt time.Time      `json:"updated_at"`
+	DeletedAt gorm.DeletedAt `gorm:"index" json:"-"`
 }

 // LibraryFile 书库文件（html/pdf/epub 等；存 data/library，不进公开静态目录）
@@ -568,6 +576,75 @@ type LibrarySection struct {
 	DeletedAt gorm.DeletedAt `gorm:"index" json:"-"`
 }

+// CodeSnippet 代码片段：用户所有，公开进广场，私有仅自己可见
+type CodeSnippet struct {
+	ID           uint           `gorm:"primaryKey" json:"id"`
+	Title        string         `gorm:"size:120;not null" json:"title"`
+	Description  string         `gorm:"type:text" json:"description"`
+	Language     string         `gorm:"size:32;not null;index" json:"language"`
+	Code         string         `gorm:"type:text;not null" json:"code"`
+	Visibility   string         `gorm:"size:16;not null;default:private;index" json:"visibility"` // public/private
+	UserID       uint           `gorm:"index;not null" json:"user_id"`
+	ForkedFromID *uint          `gorm:"index" json:"forked_from_id"`
+	CopyCount    int            `gorm:"not null;default:0" json:"copy_count"`
+	ViewCount    int            `gorm:"not null;default:0" json:"view_count"`
+	CommentCount int            `gorm:"not null;default:0" json:"comment_count"`
+	ForkCount    int            `gorm:"not null;default:0" json:"fork_count"`
+	CreatedAt    time.Time      `json:"created_at"`
+	UpdatedAt    time.Time      `json:"updated_at"`
+	DeletedAt    gorm.DeletedAt `gorm:"index" json:"-"`
+}
+
+// SnippetVersion 编辑前旧值快照（同 PostEditHistory 思路）
+type SnippetVersion struct {
+	ID             uint      `gorm:"primaryKey" json:"id"`
+	SnippetID      uint      `gorm:"index;not null" json:"snippet_id"`
+	EditorID       uint      `gorm:"index;not null" json:"editor_id"`
+	OldTitle       string    `gorm:"size:120;not null;default:''" json:"old_title"`
+	OldLanguage    string    `gorm:"size:32;not null;default:''" json:"old_language"`
+	OldDescription string    `gorm:"type:text" json:"old_description"`
+	OldCode        string    `gorm:"type:text;not null" json:"old_code"`
+	CreatedAt      time.Time `gorm:"index" json:"created_at"`
+}
+
+// SnippetComment 片段评论（楼层树：ParentID 空=主评，非空=回复；RootID=所属主楼）
+type SnippetComment struct {
+	ID         uint           `gorm:"primaryKey" json:"id"`
+	SnippetID  uint           `gorm:"index;not null" json:"snippet_id"`
+	UserID     uint           `gorm:"index;not null" json:"user_id,omitempty"`
+	ParentID   *uint          `gorm:"index" json:"parent_id"`
+	RootID     *uint          `gorm:"index" json:"root_id"`
+	Depth      int            `gorm:"not null;default:0" json:"depth"`
+	Content    string         `gorm:"type:text;not null" json:"content"`
+	DeleteType string         `gorm:"size:32;default:''" json:"delete_type,omitempty"`
+	DeletedBy  uint           `gorm:"not null;default:0" json:"deleted_by,omitempty"`
+	CreatedAt  time.Time      `json:"created_at"`
+	UpdatedAt  time.Time      `json:"updated_at"`
+	DeletedAt  gorm.DeletedAt `gorm:"index" json:"-"`
+}
+
+// SnippetCommentEditHistory 片段评论修订快照（每次编辑前的旧正文；登录用户可见）
+type SnippetCommentEditHistory struct {
+	ID         uint      `gorm:"primaryKey" json:"id"`
+	CommentID  uint      `gorm:"index;not null" json:"comment_id"`
+	EditorID   uint      `gorm:"index;not null" json:"editor_id"`
+	OldContent string    `gorm:"type:text;not null" json:"old_content"`
+	CreatedAt  time.Time `gorm:"index" json:"created_at"`
+}
+
+const (
+	SnippetVisibilityPublic  = "public"
+	SnippetVisibilityPrivate = "private"
+)
+
+// NormalizeSnippetVisibility 归一化可见性：空或未知值一律回落 private
+func NormalizeSnippetVisibility(v string) string {
+	if v == SnippetVisibilityPublic {
+		return SnippetVisibilityPublic
+	}
+	return SnippetVisibilityPrivate
+}
+
 // SiteSetting 站点级键值设置（如历史在线峰值 peak_online）
 type SiteSetting struct {
 	Key       string    `gorm:"primaryKey;size:64" json:"key"`
@@ -590,20 +667,20 @@ type SidebarWidget struct {

 // FriendLink 友情链接；申请审批制，status=pending 经管理员 approve 后前台可见
 type FriendLink struct {
-	ID            uint           `gorm:"primarykey" json:"id"`
-	Name          string         `gorm:"size:64;not null" json:"name"`
-	URL           string         `gorm:"size:512;not null" json:"url"`
-	Description   string         `gorm:"size:255" json:"description"`
-	LogoURL       string         `gorm:"size:512" json:"logo_url"`
-	Category      string         `gorm:"size:32;index" json:"category"`
-	ReciprocalURL string         `gorm:"size:512" json:"reciprocal_url"` // 申请人填写的回链地址，供站长核对
-	SortOrder     int            `gorm:"not null;default:0;index" json:"sort_order"`
-	Status        string         `gorm:"size:16;not null;default:'pending';index" json:"status"` // pending|approved|rejected
-	ApplicantUserID *uint        `gorm:"index" json:"applicant_user_id,omitempty"` // 后台直接新建时为 nil
-	RejectReason  string         `gorm:"size:255" json:"reject_reason,omitempty"`
-	CreatedAt     time.Time      `json:"created_at"`
-	UpdatedAt     time.Time      `json:"updated_at"`
-	DeletedAt     gorm.DeletedAt `gorm:"index" json:"-"`
+	ID              uint           `gorm:"primarykey" json:"id"`
+	Name            string         `gorm:"size:64;not null" json:"name"`
+	URL             string         `gorm:"size:512;not null" json:"url"`
+	Description     string         `gorm:"size:255" json:"description"`
+	LogoURL         string         `gorm:"size:512" json:"logo_url"`
+	Category        string         `gorm:"size:32;index" json:"category"`
+	ReciprocalURL   string         `gorm:"size:512" json:"reciprocal_url"` // 申请人填写的回链地址，供站长核对
+	SortOrder       int            `gorm:"not null;default:0;index" json:"sort_order"`
+	Status          string         `gorm:"size:16;not null;default:'pending';index" json:"status"` // pending|approved|rejected
+	ApplicantUserID *uint          `gorm:"index" json:"applicant_user_id,omitempty"`               // 后台直接新建时为 nil
+	RejectReason    string         `gorm:"size:255" json:"reject_reason,omitempty"`
+	CreatedAt       time.Time      `json:"created_at"`
+	UpdatedAt       time.Time      `json:"updated_at"`
+	DeletedAt       gorm.DeletedAt `gorm:"index" json:"-"`
 }

 // SiteDailyStats 站点日维度访问量（轻量 PV/UV）
@@ -652,12 +729,21 @@ const (
 	AttachmentKindImage  = "image"  // 通用图片（帖子插图等，媒体库统一管理）
 )

-// Attachment 用户上传的附件（当前仅头像，全部为 WebP）
+// 附件来源（Source）：媒体库分组依据，决定"从图库选图"时是否可直接复用
+const (
+	AttachmentSourcePost           = "post"            // 帖子/文章编辑器插图（默认）
+	AttachmentSourceLibraryCover   = "library_cover"   // 书库封面（选用时已复制过，再次选可直接引用）
+	AttachmentSourceLibraryContent = "library_content" // 书库正文内容插图
+)
+
+// Attachment 用户上传的附件（头像与帖子插图等公开图片）
 type Attachment struct {
 	ID        uint      `gorm:"primaryKey" json:"id"`
 	UserID    uint      `gorm:"index:idx_attachment_user_kind,priority:1;not null" json:"user_id"`
 	Kind      string    `gorm:"size:16;index:idx_attachment_user_kind,priority:2;not null" json:"kind"`
+	Source    string    `gorm:"size:24;not null;default:'post'" json:"source"`
 	URL       string    `gorm:"size:512;not null" json:"url"`
+	BlobHash  string    `gorm:"size:64;not null;default:'';index" json:"-"` // 内容寻址 hash；空=历史文件，不走引用计数
 	MIME      string    `gorm:"size:32;not null;default:image/webp" json:"mime"`
 	Size      int       `gorm:"not null;default:0" json:"size"` // 裁剪后文件字节数（大小限制以此为准）
 	Width     int       `gorm:"not null;default:0" json:"width"`
@@ -665,6 +751,20 @@ type Attachment struct {
 	CreatedAt time.Time `gorm:"index" json:"created_at"`
 }

+// Blob 内容寻址物理文件：对【最终存储字节】算 SHA-256，同内容多次上传共享一份底层存储，
+// 业务行（Attachment/PostAttachment 及未来的聊天文件消息）只引用 hash，按引用计数回收。
+// 公开（帖子插图/头像）与私有（付费附件、未来私聊文件）是两个互不可见的命名空间：
+// 同字节也各自存一份，避免私有文件借公开链接（/api/media/<id>）被越权读取。
+type Blob struct {
+	Hash      string    `gorm:"primaryKey;size:64" json:"-"` // 最终存储字节的 SHA-256 hex（图片为转码后的字节）
+	Public    bool      `gorm:"primaryKey" json:"-"`
+	RefCount  int64     `gorm:"not null;default:0" json:"-"`
+	Size      int       `gorm:"not null;default:0" json:"-"`
+	MIME      string    `gorm:"size:128;not null;default:''" json:"-"`
+	ObjectID  string    `gorm:"size:96;not null;default:''" json:"-"` // S3 后端的 StoredObject ID；本地后端为空
+	CreatedAt time.Time `json:"-"`
+}
+
 // UserBoard 板块管理员的板块授权（多对多；仅 role=board_admin 的行生效）
 type UserBoard struct {
 	ID        uint      `gorm:"primaryKey" json:"id"`
@@ -736,6 +836,7 @@ type ChatRoomMember struct {
 	Role              string     `gorm:"size:16;not null;default:member" json:"role"`
 	LastReadMessageID uint       `gorm:"not null;default:0" json:"last_read_message_id"`
 	Muted             bool       `gorm:"not null;default:false" json:"muted"` // 被群主禁言
+	MutedUntil        *time.Time `json:"muted_until,omitempty"`               // 禁言截止时间；nil 表示永久
 	PinnedAt          *time.Time `json:"pinned_at,omitempty"`                 // 该用户个人置顶时间；大厅强制置顶不依赖此字段
 	CreatedAt         time.Time  `json:"created_at"`
 	UpdatedAt         time.Time  `json:"updated_at"`
@@ -747,17 +848,18 @@ type ChatRoomMember struct {
 type ChatMessage struct {
 	ID         uint           `gorm:"primaryKey" json:"id"`
 	RoomID     uint           `gorm:"index:idx_chat_room_created,priority:1;not null" json:"room_id"`
-	SenderID   uint           `gorm:"index;not null" json:"sender_id"`
+	SenderID   uint           `gorm:"index" json:"sender_id"` // 0 表示系统消息（is_system=true）
 	Content    string         `gorm:"type:varchar(2000);not null" json:"content"`
 	ReplyToID  uint           `gorm:"not null;default:0;index" json:"reply_to_id"`    // 引用的消息 ID，0 表示无引用
 	ReplySnap  string         `gorm:"size:512;not null;default:''" json:"reply_snap"` // 引用快照「昵称: 摘要」，原文撤回后仍可展示
 	MentionIDs string         `gorm:"size:512;not null;default:''" json:"-"`          // 被@用户 ID 逗号分隔（落通知用）
 	RecalledAt *time.Time     `json:"recalled_at,omitempty"`
 	RecalledBy uint           `gorm:"not null;default:0" json:"recalled_by"`
+	IsSystem   bool           `gorm:"not null;default:false" json:"is_system"` // 系统提示（如禁言通知），sender_id=0
 	CreatedAt  time.Time      `gorm:"index:idx_chat_room_created,priority:2" json:"created_at"`
 	DeletedAt  gorm.DeletedAt `gorm:"index" json:"-"`

-	Sender User `gorm:"foreignKey:SenderID" json:"sender,omitempty"`
+	Sender User `gorm:"foreignKey:SenderID;constraint:-" json:"sender,omitempty"` // constraint:- 禁用 FK，支持 sender_id=0 的系统消息
 	// RecalledBy=0 时不建 FK；Preload 仅用于已撤回消息展示撤回者昵称
 	Recaller *User `gorm:"foreignKey:RecalledBy;constraint:-" json:"recaller,omitempty"`
 }
--- a/backend/model/operations.go
+++ b/backend/model/operations.go
@@ -51,7 +51,7 @@ type EmailChallenge struct {

 // Every remote object pins the immutable configuration revision that wrote it.
 type StoredObject struct {
-	ID         string    `gorm:"primaryKey;size:64" json:"id"`
+	ID         string    `gorm:"primaryKey;size:96" json:"id"`
 	ConfigName string    `gorm:"size:64;index" json:"-"`
 	Key        string    `gorm:"size:512" json:"-"`
 	MIME       string    `gorm:"size:128" json:"-"`
--- a/backend/realtime/hub.go
+++ b/backend/realtime/hub.go
@@ -18,18 +18,19 @@ import (

 // 事件类型：前后端共享的单层 JSON 协议契约，禁止手拼 JSON / 双重编码
 const (
-	EventHello           = "hello"            // 建连欢迎帧（含在线用户快照）
-	EventPong            = "pong"             // 应用层心跳应答
-	EventSettingsChanged = "settings:changed" // 站点设置（主题色）变更，全员广播
-	EventPresenceUpdate  = "presence:update"  // 用户上/下线，仅 staff 房间
-	EventChatMessage     = "chat:message"          // 群聊新消息，推 chat:{roomID}
-	EventChatMembership  = "chat:membership"       // 群成员关系变更（被踢/群解散/被邀请），推 user:{id}
-	EventNotificationNew = "notification:new"      // 新站内通知（如群聊 @），推 user:{id}
-	EventFeedChanged     = "feed:changed"          // 帖子流有公开新内容（三期），全员广播
-	EventChatRecalled    = "chat:message_recalled" // 消息撤回，推 chat:{roomID}
-	EventChatUnread      = "chat:unread"           // 未读增量，推 user:{id}（未订阅房间也能实时角标）
-	EventModerationChanged = "moderation:changed"  // 待审队列变化，推 staff 房间（客户端各自 HTTP 校准角标）
-	EventSessionReplaced = "session:replaced"      // 登录态被顶/被剔除，推 user:{id}（旧设备即时感知并提示重新登录）
+	EventHello             = "hello"                 // 建连欢迎帧（含在线用户快照）
+	EventPong              = "pong"                  // 应用层心跳应答
+	EventSettingsChanged   = "settings:changed"      // 站点设置（主题色）变更，全员广播
+	EventPresenceUpdate    = "presence:update"       // 用户上/下线，仅 staff 房间
+	EventChatMessage       = "chat:message"          // 群聊新消息，推 chat:{roomID}
+	EventChatMembership    = "chat:membership"       // 群成员关系变更（被踢/群解散/被邀请），推 user:{id}
+	EventNotificationNew   = "notification:new"      // 新站内通知（如群聊 @），推 user:{id}
+	EventFeedChanged       = "feed:changed"          // 帖子流有公开新内容（三期），全员广播
+	EventChatRecalled      = "chat:message_recalled" // 消息撤回，推 chat:{roomID}
+	EventChatMemberMuted   = "chat:member_muted"     // 成员被禁言/解禁，推 chat:{roomID}
+	EventChatUnread        = "chat:unread"           // 未读增量，推 user:{id}（未订阅房间也能实时角标）
+	EventModerationChanged = "moderation:changed"    // 待审队列变化，推 staff 房间（客户端各自 HTTP 校准角标）
+	EventSessionReplaced   = "session:replaced"      // 登录态被顶/被剔除，推 user:{id}（旧设备即时感知并提示重新登录）
 )

 // RoomStaff 管理团队房间（板块管理员及以上）
--- a/backend/router/router.go
+++ b/backend/router/router.go
@@ -101,7 +101,10 @@ func Setup(cfg *config.Config) (*gin.Engine, error) {
 	postFileSvc.WithOperations(ops)
 	pointsSvc := service.NewPointsService(model.DB)
 	leaderboardSvc := service.NewLeaderboardService(model.DB)
-	librarySvc := service.NewLibraryService(model.DB, cfg.DataDir).WithSetting(settingSvc)
+	librarySvc := service.NewLibraryService(model.DB, cfg.DataDir).
+		WithSetting(settingSvc).
+		WithUploadsDir(filepath.Join(cfg.DataDir, "uploads"))
+	snippetSvc := service.NewSnippetService(model.DB)
 	adminUserSvc := service.NewAdminUserService(model.DB)
 	legacyImportSvc := service.NewLegacyImportService(model.DB, filepath.Join(cfg.DataDir, "uploads"))
 	moderationSvc := service.NewModerationService(model.DB, notifSvc)
@@ -163,6 +166,7 @@ func Setup(cfg *config.Config) (*gin.Engine, error) {
 		Badge:          badgeSvc,
 		LeaderboardSvc: leaderboardSvc,
 		LibrarySvc:     librarySvc,
+		SnippetSvc:     snippetSvc,
 	}
 	// 通知落库后统一推 WS 红点（点赞/评论/审核/@ 等共用）
 	notifSvc.OnNotifyNew = func(userID uint) {
@@ -183,6 +187,9 @@ func Setup(cfg *config.Config) (*gin.Engine, error) {
 	// 挂在 OptionalAuth 之后可顺带拿到登录用户
 	r.Use(middleware.VisitCapture(visitSvc))

+	// 上传文件长缓存（必须先于 r.Static 注册；文件名随机不覆盖，可 immutable）
+	r.Use(middleware.UploadStaticCache())
+
 	// 上传文件静态服务（data/uploads → /uploads）
 	r.Static("/uploads", filepath.Join(cfg.DataDir, "uploads"))

@@ -209,7 +216,6 @@ func Setup(cfg *config.Config) (*gin.Engine, error) {
 		pubAPI.POST("/posts/:id/unlock-password", middleware.CSRFMiddleware(), middleware.RateLimitMiddleware(limiter, service.RateHidePassword), h.UnlockPostPassword)
 		pubAPI.GET("/posts/:id/attachments/:aid/download", h.DownloadPostAttachment)
 		pubAPI.GET("/posts/:id/comments", h.PostComments)
-		pubAPI.GET("/posts/:id/comments/:cid", h.CommentLocation)
 		pubAPI.GET("/users/:id", h.UserProfile)
 		pubAPI.GET("/users/:id/comments", h.UserComments)
 		pubAPI.GET("/users/:id/favorites", h.UserFavorites)
@@ -225,7 +231,16 @@ func Setup(cfg *config.Config) (*gin.Engine, error) {
 		pubAPI.GET("/library", h.LibraryList)
 		pubAPI.GET("/library/:slug", h.LibraryDetail)
 		pubAPI.GET("/library/files/:fid/download", h.LibraryFileDownload)
+		// 代码片段（公开广场/详情/评论/Fork 列表）
+		pubAPI.GET("/snippets", h.SnippetList)
+		pubAPI.GET("/snippets/languages", h.SnippetLanguages)
+		pubAPI.GET("/snippets/stats", h.SnippetStats)
+		pubAPI.GET("/snippets/:id", h.SnippetDetail)
+		pubAPI.GET("/snippets/:id/comments", h.SnippetComments)
+		pubAPI.GET("/snippets/:id/forks", h.SnippetForks)
 		pubAPI.GET("/site-state", h.SiteState)
+		// 自适应图片变体（?u=<源图URL>&w=<白名单宽度>，公开只读、immutable 缓存）
+		pubAPI.GET("/img", h.ImageVariant)
 		pubAPI.GET("/media/:object", h.PublicObject)
 		pubAPI.POST("/auth/code", middleware.CSRFMiddleware(), h.SendEmailCode)
 		pubAPI.POST("/auth/reset-password", middleware.CSRFMiddleware(), h.ResetPassword)
@@ -302,6 +317,19 @@ func Setup(cfg *config.Config) (*gin.Engine, error) {
 		// 时间线：从 Git releases 页导入更新日志
 		api.POST("/timeline/from-releases", middleware.StaffExempt(middleware.RateLimitUserMiddleware(limiter, service.RateTimelineGit)), h.TimelineFromReleases)

+		// 代码片段（登录区）
+		api.POST("/snippets", middleware.StaffExempt(middleware.RateLimitMiddleware(limiter, service.RateSnippet)), h.SnippetCreate)
+		api.GET("/snippets/mine", h.SnippetMine)
+		api.PUT("/snippets/:id", h.SnippetUpdate)
+		api.DELETE("/snippets/:id", h.SnippetDelete)
+		api.POST("/snippets/:id/fork", middleware.StaffExempt(middleware.RateLimitMiddleware(limiter, service.RateSnippet)), h.SnippetFork)
+		api.POST("/snippets/:id/copy", h.SnippetCopy)
+		api.GET("/snippets/:id/history", h.SnippetHistory)
+		api.POST("/snippets/:id/comments", middleware.StaffExempt(middleware.RateLimitMiddleware(limiter, service.RateComment)), h.SnippetCommentCreate)
+		api.PUT("/snippets/:id/comments/:cid", middleware.StaffExempt(middleware.RateLimitMiddleware(limiter, service.RateComment)), h.SnippetCommentUpdate)
+		api.DELETE("/snippets/:id/comments/:cid", h.SnippetCommentDelete)
+		api.GET("/snippets/:id/comments/:cid/history", h.SnippetCommentHistory)
+
 		// 群聊（二期）：建群/成员/消息/未读；全站关闭消息时前台一律 403
 		chatAPI := api.Group("/chat", h.RequireMessagesOpen)
 		{
@@ -376,23 +404,34 @@ func Setup(cfg *config.Config) (*gin.Engine, error) {
 		// 群聊监管：移出后挂到 RequireAuth 组，允许「仅群管/消息 flag」用户访问
 		// （见下方 msgAPI）

-		// 站点公告文章管理（管理员及以上）
-		announceAPI := staffAPI.Group("", authMW.RequirePerm(service.PermAnnouncements))
+		// 渠道内容管理（公告/单页/书库/广告）：RequireActor 允许任意登录账号进入，
+		// 由 RequirePerm 按渠道权限码放行——角色默认管理员及以上，
+		// 超管/站长亦可将单个渠道授予板块管理员或普通用户（账号级授权）
+		permAPI := r.Group("/api/admin", authMW.RequireActor(), middleware.CSRFMiddleware())
+
+		// 站点公告文章管理（PermAnnouncements）
+		announceAPI := permAPI.Group("", authMW.RequirePerm(service.PermAnnouncements))
 		announceAPI.GET("/announcements", h.AdminListAnnouncements)
 		announceAPI.POST("/announcements", h.AdminCreateAnnouncement)
 		announceAPI.PUT("/announcements/:id", h.AdminUpdateAnnouncement)
 		announceAPI.POST("/announcements/:id/pin", h.AdminToggleAnnouncementPin)
 		announceAPI.DELETE("/announcements/:id", h.AdminDeleteAnnouncement)
-		announceAPI.GET("/pages", h.AdminListSitePages)
-		announceAPI.POST("/pages", h.AdminCreateSitePage)
-		announceAPI.PUT("/pages/:id", h.AdminUpdateSitePage)
-		announceAPI.DELETE("/pages/:id", h.AdminDeleteSitePage)
-		announceAPI.DELETE("/pages/:id/purge", h.AdminPurgeSitePage)

-		// 书库管理（管理员及以上，同公告/单页权限）
-		libraryAPI := staffAPI.Group("/library", authMW.RequirePerm(service.PermAnnouncements))
+		// 站点单页管理（PermPages）
+		pagesAPI := permAPI.Group("", authMW.RequirePerm(service.PermPages))
+		pagesAPI.GET("/pages", h.AdminListSitePages)
+		pagesAPI.POST("/pages", h.AdminCreateSitePage)
+		pagesAPI.PUT("/pages/:id", h.AdminUpdateSitePage)
+		pagesAPI.DELETE("/pages/:id", h.AdminDeleteSitePage)
+		pagesAPI.DELETE("/pages/:id/purge", h.AdminPurgeSitePage)
+
+		// 书库管理（PermLibrary）
+		libraryAPI := permAPI.Group("/library", authMW.RequirePerm(service.PermLibrary))
 		{
 			libraryAPI.GET("/docs", h.AdminListLibraryDocs)
+			libraryAPI.GET("/export", h.AdminExportAllLibrary)
+			libraryAPI.POST("/import", middleware.RateLimitMiddleware(limiter, service.RateUpload), h.AdminImportLibrary)
+			libraryAPI.GET("/docs/:id/export", h.AdminExportLibraryDoc)
 			libraryAPI.POST("/docs", h.AdminCreateLibraryDoc)
 			libraryAPI.PUT("/docs/:id", h.AdminUpdateLibraryDoc)
 			libraryAPI.DELETE("/docs/:id", h.AdminDeleteLibraryDoc)
@@ -409,8 +448,8 @@ func Setup(cfg *config.Config) (*gin.Engine, error) {
 			libraryAPI.POST("/cover/from-media", middleware.RateLimitMiddleware(limiter, service.RateUpload), h.UploadLibraryCoverFromMedia)
 		}

-		// 广告位管理（管理员及以上）
-		adsAPI := staffAPI.Group("", authMW.RequirePerm(service.PermAnnouncements))
+		// 广告位管理（PermAds）
+		adsAPI := permAPI.Group("", authMW.RequirePerm(service.PermAds))
 		adsAPI.GET("/ads/config", h.AdminGetAdsConfig)
 		adsAPI.PUT("/ads/config", h.AdminSaveAdsConfig)
 		adsAPI.GET("/ads", h.AdminListAds)
@@ -477,6 +516,8 @@ func Setup(cfg *config.Config) (*gin.Engine, error) {
 			usersAPI.GET("/users", h.AdminListUsers)
 			usersAPI.PUT("/users/:id/role", h.AdminUpdateUserRole)
 			usersAPI.PUT("/users/:id/messages", h.AdminSetUserMessages)
+			usersAPI.GET("/users/:id/perms", h.AdminGetUserPerms)
+			usersAPI.PUT("/users/:id/perms", h.AdminSetUserPerms)
 			usersAPI.PUT("/users/:id/ban", h.AdminSetUserBan)
 			usersAPI.GET("/users/:id/login-logs", h.AdminUserLoginLogs)
 			// 积分管理：手动调整（加分计累计/扣分仅扣余额）与积分流水分页
@@ -489,6 +530,11 @@ func Setup(cfg *config.Config) (*gin.Engine, error) {
 			usersAPI.GET("/users/:id/messages", h.AdminUserAuditMessages)
 		}

+		// 代码片段管理（任意 staff）
+		staffAPI.GET("/snippets", h.AdminSnippetList)
+		staffAPI.DELETE("/snippets/:id", h.AdminSnippetDelete)
+		staffAPI.PUT("/snippets/:id/visibility", h.AdminSnippetSetVisibility)
+
 		// 板块管理（仅站长）：增删改、排序、版主授权
 		boardsAPI := staffAPI.Group("", authMW.RequirePerm(service.PermBoards))
 		{
--- a/backend/service/actor.go
+++ b/backend/service/actor.go
@@ -1,6 +1,8 @@
 package service

 import (
+	"encoding/json"
+	"sort"
 	"strings"

 	"github.com/freefire/jiang13-bbs/model"
@@ -10,21 +12,119 @@ import (
 // 板块管理员的板块范围由 Actor.BoardIDs 在业务层二次校验。
 const (
 	PermUsers         = "users"         // 用户与权限管理（超管/站长）
-	PermAnnouncements = "announcements" // 公告管理（管理员及以上）
+	PermAnnouncements = "announcements" // 公告管理（管理员及以上；可账号级授予）
+	PermPages         = "pages"         // 单页管理（管理员及以上；可账号级授予）
+	PermLibrary       = "library"       // 书库管理（管理员及以上；可账号级授予）
+	PermAds           = "ads"           // 广告与赞助管理（管理员及以上；可账号级授予）
 	PermSettings      = "settings"      // 站点外观设置（超管/站长）
 	PermModeration    = "moderation"    // 内容审核（任意管理角色，板块范围受限）
 	PermMessages      = "messages"      // 后台消息管理（站长/超管/站点消息 flag；群管另有业务层放行）
 	PermBoards        = "boards"        // 板块管理（仅站长）
 )

+// GrantablePerms 可账号级授予的渠道权限码（授予者需持有 PermUsers）。
+// 管理员及以上角色对这些渠道为角色自带，账号级授予只对板块管理员/普通用户生效。
+var GrantablePerms = []string{PermAnnouncements, PermPages, PermLibrary, PermAds}
+
+// ValidPermOverride 权限码是否可被账号级授予
+func ValidPermOverride(p string) bool {
+	for _, g := range GrantablePerms {
+		if p == g {
+			return true
+		}
+	}
+	return false
+}
+
+// NormalizePermOverrides 白名单过滤 + 去重 + 排序，得到可落库的权限码集
+func NormalizePermOverrides(perms []string) []string {
+	seen := map[string]bool{}
+	out := make([]string, 0, len(perms))
+	for _, p := range perms {
+		p = strings.TrimSpace(p)
+		if p == "" || seen[p] || !ValidPermOverride(p) {
+			continue
+		}
+		seen[p] = true
+		out = append(out, p)
+	}
+	sort.Strings(out)
+	return out
+}
+
+// ParsePermOverrides 解析 users.perm_overrides JSON 列（容错：非法内容视为空）
+func ParsePermOverrides(raw string) []string {
+	if raw == "" {
+		return []string{}
+	}
+	var arr []string
+	if err := json.Unmarshal([]byte(raw), &arr); err != nil {
+		return []string{}
+	}
+	return NormalizePermOverrides(arr)
+}
+
+// SerializePermOverrides 序列化为落库 JSON（空集统一 "[]"，避免 NULL/空串分歧）
+func SerializePermOverrides(perms []string) string {
+	norm := NormalizePermOverrides(perms)
+	b, err := json.Marshal(norm)
+	if err != nil {
+		return "[]"
+	}
+	return string(b)
+}
+
+// roleDefaultPerm 角色对功能点的固有权限（不含账号级授予）
+func roleDefaultPerm(role model.Role, p string) bool {
+	switch p {
+	case PermBoards:
+		return role == model.RoleOwner
+	case PermUsers, PermSettings:
+		return role == model.RoleSuperAdmin || role == model.RoleOwner
+	case PermAnnouncements, PermPages, PermLibrary, PermAds:
+		return model.RoleLevel(role) >= model.RoleLevel(model.RoleAdmin)
+	case PermModeration:
+		return model.IsStaff(role)
+	}
+	return false
+}
+
+// EffectivePerms 生效权限码列表（角色默认 ∪ 账号授予 + 消息管理），
+// 供 /me 下发，前端据此渲染后台入口/按钮；最终权限仍以 HasPerm 校验为准。
+func EffectivePerms(role model.Role, permOverridesRaw string, canManageMessages bool) []string {
+	set := map[string]bool{}
+	all := append([]string{
+		PermUsers, PermAnnouncements, PermPages, PermLibrary, PermAds,
+		PermSettings, PermModeration, PermBoards,
+	}, GrantablePerms...)
+	for _, p := range all {
+		if roleDefaultPerm(role, p) {
+			set[p] = true
+		}
+	}
+	for _, p := range ParsePermOverrides(permOverridesRaw) {
+		set[p] = true
+	}
+	if role == model.RoleOwner || role == model.RoleSuperAdmin || canManageMessages {
+		set[PermMessages] = true
+	}
+	out := make([]string, 0, len(set))
+	for p := range set {
+		out = append(out, p)
+	}
+	sort.Strings(out)
+	return out
+}
+
 // Actor 当前请求操作者的实时权限快照（每次后台请求从 DB 现取，
 // 不依赖 JWT 内的 role claim，角色/授权变更立即生效）
 type Actor struct {
 	ID                uint
 	Username          string
 	Role              model.Role
-	BoardIDs          []uint // 板块管理员被授权的板块；其他角色为空
-	CanManageMessages bool   // 站点级消息管理 flag（站长授予）；站长/超管不必依赖此字段
+	BoardIDs          []uint   // 板块管理员被授权的板块；其他角色为空
+	CanManageMessages bool     // 站点级消息管理 flag（站长授予）；站长/超管不必依赖此字段
+	ExtraPerms        []string // 账号级授予的渠道权限（角色固有之外的增量）
 }

 // IsStaff 是否管理团队成员
@@ -32,23 +132,22 @@ func (a *Actor) IsStaff() bool {
 	return a != nil && model.IsStaff(a.Role)
 }

-// HasPerm 是否拥有某后台功能点
+// HasPerm 是否拥有某后台功能点：角色固有权限 ∪ 账号级授予
 func (a *Actor) HasPerm(p string) bool {
 	if a == nil {
 		return false
 	}
-	switch p {
-	case PermBoards:
-		return a.Role == model.RoleOwner
-	case PermUsers, PermSettings:
-		return a.Role == model.RoleSuperAdmin || a.Role == model.RoleOwner
-	case PermAnnouncements:
-		return model.RoleLevel(a.Role) >= model.RoleLevel(model.RoleAdmin)
-	case PermModeration:
-		return a.IsStaff()
-	case PermMessages:
+	if roleDefaultPerm(a.Role, p) {
+		return true
+	}
+	if p == PermMessages {
 		return a.HasSiteMessagePerm()
 	}
+	for _, e := range a.ExtraPerms {
+		if e == p {
+			return true
+		}
+	}
 	return false
 }

@@ -113,15 +212,16 @@ func (a *Actor) CanAssignRole(target model.Role) bool {
 	return a.HasPerm(PermUsers)
 }

-// LoadActor 读取用户实时角色与板块授权
+// LoadActor 读取用户实时角色、板块授权与账号级渠道权限
 func (s *AuthService) LoadActor(id uint) (*Actor, error) {
 	var u model.User
-	if err := s.db.Select("id", "username", "role", "can_manage_messages").First(&u, id).Error; err != nil {
+	if err := s.db.Select("id", "username", "role", "can_manage_messages", "perm_overrides").First(&u, id).Error; err != nil {
 		return nil, err
 	}
 	actor := &Actor{
 		ID: u.ID, Username: u.Username, Role: u.Role, BoardIDs: []uint{},
 		CanManageMessages: u.CanManageMessages,
+		ExtraPerms:        ParsePermOverrides(u.PermOverrides),
 	}
 	if u.Role == model.RoleBoardAdmin {
 		var ids []uint
--- a/backend/service/ad.go
+++ b/backend/service/ad.go
@@ -17,25 +17,25 @@ import (
 const (
 	SettingKeyAdsConfig = "ads_config"

-	AdMaxTitleRunes  = 24
-	AdMaxNoteRunes   = 100
-	AdMaxImageShow   = 5
-	AdMaxTextShow    = 6
-	AdMaxActiveShow  = AdMaxImageShow + AdMaxTextShow
-	AdDefaultTitle   = "自助推广"
+	AdMaxTitleRunes = 24
+	AdMaxNoteRunes  = 100
+	AdMaxImageShow  = 5
+	AdMaxTextShow   = 6
+	AdMaxActiveShow = AdMaxImageShow + AdMaxTextShow
+	AdDefaultTitle  = "自助推广"
 )

 var (
-	ErrAdNotFound      = errors.New("广告不存在")
-	ErrAdForbidden     = errors.New("无权操作")
-	ErrAdInvalid       = errors.New("广告参数无效")
-	ErrAdCaptcha       = errors.New("验证码错误或已过期")
-	ErrAdDisabled      = errors.New("自助推广暂未开放")
-	ErrAdBadPayment    = errors.New("请选择有效的支付方式")
-	ErrAdBadDuration   = errors.New("请选择有效的投放时长")
-	hexColorRe         = regexp.MustCompile(`^#([0-9a-fA-F]{6})$`)
-	adImageHTTPSRe     = regexp.MustCompile(`(?i)^https://[^\s\\]{1,500}$`)
-	adImageUploadRe    = regexp.MustCompile(`(?i)^/uploads/(ads|images|brand)/[0-9a-f]{32}\.(png|jpe?g|gif|webp)$`)
+	ErrAdNotFound    = errors.New("广告不存在")
+	ErrAdForbidden   = errors.New("无权操作")
+	ErrAdInvalid     = errors.New("广告参数无效")
+	ErrAdCaptcha     = errors.New("验证码错误或已过期")
+	ErrAdDisabled    = errors.New("自助推广暂未开放")
+	ErrAdBadPayment  = errors.New("请选择有效的支付方式")
+	ErrAdBadDuration = errors.New("请选择有效的投放时长")
+	hexColorRe       = regexp.MustCompile(`^#([0-9a-fA-F]{6})$`)
+	adImageHTTPSRe   = regexp.MustCompile(`(?i)^https://[^\s\\]{1,500}$`)
+	adImageUploadRe  = regexp.MustCompile(`(?i)^/uploads/(ads|images|brand)/[0-9a-f]{32}\.(png|jpe?g|gif|webp)$`)
 )

 // AdDurationOption 可购时长档位（图片 / 文字广告分别计价）
--- a/backend/service/admin_content.go
+++ b/backend/service/admin_content.go
@@ -49,11 +49,11 @@ const (

 // AdminContentCounts 当前操作者可见范围内的数量（用于页内 Tab）
 type AdminContentCounts struct {
-	PostsLive      int64 `json:"posts_live"`
-	PostsPending   int64 `json:"posts_pending"`
-	PostsRejected  int64 `json:"posts_rejected"`
-	PostsDeleted   int64 `json:"posts_deleted"`
-	CommentsLive   int64 `json:"comments_live"`
+	PostsLive        int64 `json:"posts_live"`
+	PostsPending     int64 `json:"posts_pending"`
+	PostsRejected    int64 `json:"posts_rejected"`
+	PostsDeleted     int64 `json:"posts_deleted"`
+	CommentsLive     int64 `json:"comments_live"`
 	CommentsPending  int64 `json:"comments_pending"`
 	CommentsRejected int64 `json:"comments_rejected"`
 	CommentsDeleted  int64 `json:"comments_deleted"`
@@ -61,32 +61,34 @@ type AdminContentCounts struct {

 // AdminContentPost 后台帖子列表项
 type AdminContentPost struct {
-	ID           uint       `json:"id"`
-	Title        string     `json:"title"`
-	Status       string     `json:"status"`
-	Deleted      bool       `json:"deleted"`
-	DeletedAt    *time.Time `json:"deleted_at,omitempty"`
-	CreatedAt    time.Time  `json:"created_at"`
-	CommentCount int        `json:"comment_count"`
-	BoardID      uint       `json:"board_id"`
+	ID           uint        `json:"id"`
+	Title        string      `json:"title"`
+	Status       string      `json:"status"`
+	Deleted      bool        `json:"deleted"`
+	DeletedAt    *time.Time  `json:"deleted_at,omitempty"`
+	CreatedAt    time.Time   `json:"created_at"`
+	CommentCount int         `json:"comment_count"`
+	BoardID      uint        `json:"board_id"`
 	Board        model.Board `json:"board"`
-	User         model.User `json:"user"`
+	User         model.User  `json:"user"`
 }

 // AdminContentComment 后台评论列表项
 type AdminContentComment struct {
-	ID        uint       `json:"id"`
-	PostID    uint       `json:"post_id"`
-	PostTitle string     `json:"post_title"`
-	BoardID   uint       `json:"board_id"`
-	Content   string     `json:"content"`
-	Status    string     `json:"status"`
-	Edited    bool       `json:"edited"` // 相对创建已编辑（同评论侧规则），用于隐藏无修订的历史入口
-	Deleted   bool       `json:"deleted"`
-	DeletedAt *time.Time `json:"deleted_at,omitempty"`
-	CreatedAt time.Time  `json:"created_at"`
+	ID        uint        `json:"id"`
+	PostID    uint        `json:"post_id"`
+	PostTitle string      `json:"post_title"`
+	BoardID   uint        `json:"board_id"`
+	Content   string      `json:"content"`
+	Status    string      `json:"status"`
+	Edited    bool        `json:"edited"` // 相对创建已编辑（同评论侧规则），用于隐藏无修订的历史入口
+	Deleted   bool        `json:"deleted"`
+	DeletedAt *time.Time  `json:"deleted_at,omitempty"`
+	CreatedAt time.Time   `json:"created_at"`
+	Floor     uint        `json:"floor"`   // 所属楼层相对序号
+	IsRoot    bool        `json:"is_root"` // 主楼/楼中楼，供前台拼 #comment-{floor}[-r{id}]
 	Board     model.Board `json:"board"`
-	User      model.User `json:"user"`
+	User      model.User  `json:"user"`
 }

 func normalizeAdminStatus(raw string) AdminContentStatus {
@@ -270,6 +272,11 @@ func (s *ModerationService) ListAdminComments(actor *Actor, status, keyword stri
 	}

 	items := make([]AdminContentComment, 0, len(rows))
+	commentIDs := make([]uint, 0, len(rows))
+	for _, r := range rows {
+		commentIDs = append(commentIDs, r.ID)
+	}
+	anchors := CommentAnchors(s.db, commentIDs)
 	for _, r := range rows {
 		it := AdminContentComment{
 			ID:        r.ID,
@@ -283,6 +290,10 @@ func (s *ModerationService) ListAdminComments(actor *Actor, status, keyword stri
 			Board:     boards[r.BoardID],
 			User:      users[r.UserID],
 		}
+		if a, ok := anchors[r.ID]; ok {
+			it.Floor = a.Floor
+			it.IsRoot = a.IsRoot
+		}
 		if r.DeletedAt.Valid {
 			it.Deleted = true
 			t := r.DeletedAt.Time
--- a/backend/service/admin_user.go
+++ b/backend/service/admin_user.go
@@ -54,6 +54,7 @@ type AdminUserItem struct {
 	BoardIDs          []uint     `json:"board_ids"`
 	Banned            bool       `json:"banned"`
 	CanManageMessages bool       `json:"can_manage_messages"`
+	PermOverrides     []string   `json:"perm_overrides"` // 账号级渠道权限（角色固有之外的增量授予）
 	PostCount         int64      `json:"post_count"`
 	CommentCount      int64      `json:"comment_count"`
 	Points            int        `json:"points"`
@@ -71,7 +72,7 @@ type AdminUserItem struct {
 // - total / admins / banned：筛选 Tab 角标（不在顶部卡片展示，避免与仪表盘重复）
 type AdminUserSummary struct {
 	Online          int64 `json:"online"`
-	InCooldown       int64 `json:"in_cooldown"`
+	InCooldown      int64 `json:"in_cooldown"`
 	Active7d        int64 `json:"active_7d"`
 	FailedLogins24h int64 `json:"failed_logins_24h"`
 	Total           int64 `json:"total"`
@@ -237,6 +238,7 @@ func (s *AdminUserService) toItems(users []model.User) []AdminUserItem {
 			BoardIDs:          []uint{},
 			Banned:            u.Banned,
 			CanManageMessages: u.CanManageMessages,
+			PermOverrides:     ParsePermOverrides(u.PermOverrides),
 			Points:            u.Points,
 			TotalPoints:       u.TotalPoints,
 			Level:             u.Level,
@@ -407,6 +409,12 @@ func (s *AdminUserService) SetStaff(operator *Actor, targetID uint, role model.R
 				return err
 			}
 		}
+		// 升至管理员及以上后渠道权限变为角色自带，账号级授予清空以免误导
+		if roleChanged && model.RoleLevel(role) >= model.RoleLevel(model.RoleAdmin) && u.PermOverrides != "" && u.PermOverrides != "[]" {
+			if err := tx.Model(&u).Update("perm_overrides", "[]").Error; err != nil {
+				return err
+			}
+		}
 		return nil
 	})
 	if err != nil {
@@ -415,6 +423,53 @@ func (s *AdminUserService) SetStaff(operator *Actor, targetID uint, role model.R
 	return s.getItem(s.db, targetID)
 }

+// GetPermOverrides 读取目标账号的渠道权限（PermUsers 持有者可读，供授权弹窗回显）
+func (s *AdminUserService) GetPermOverrides(operator *Actor, targetID uint) ([]string, error) {
+	if operator == nil || !operator.HasPerm(PermUsers) {
+		return nil, ErrCannotAssignRole
+	}
+	var u model.User
+	if err := s.db.Select("id", "perm_overrides").First(&u, targetID).Error; err != nil {
+		return nil, err
+	}
+	return ParsePermOverrides(u.PermOverrides), nil
+}
+
+// SetPermOverrides 授予/撤销账号级渠道权限（公告/单页/书库/广告）。
+// 授予者需持有 PermUsers（超管/站长）；目标为管理员及以上时渠道为角色自带，
+// 授权无意义，强制清空。Actor 每次请求现查 DB，变更即时生效，无需强制下线。
+func (s *AdminUserService) SetPermOverrides(operator *Actor, targetID uint, perms []string) (*AdminUserItem, error) {
+	if operator == nil || !operator.HasPerm(PermUsers) {
+		return nil, ErrCannotAssignRole
+	}
+	if operator.ID == targetID {
+		return nil, ErrAdminSelfAction
+	}
+	norm := NormalizePermOverrides(perms)
+	err := s.db.Transaction(func(tx *gorm.DB) error {
+		var u model.User
+		if err := tx.First(&u, targetID).Error; err != nil {
+			return err
+		}
+		if u.Role == model.RoleOwner {
+			return ErrProtectedOwner
+		}
+		// 管理员及以上角色自带全部渠道权限，账号级授予保持为空
+		if model.RoleLevel(u.Role) >= model.RoleLevel(model.RoleAdmin) {
+			norm = []string{}
+		}
+		raw := SerializePermOverrides(norm)
+		if u.PermOverrides == raw {
+			return nil
+		}
+		return tx.Model(&u).Update("perm_overrides", raw).Error
+	})
+	if err != nil {
+		return nil, err
+	}
+	return s.getItem(s.db, targetID)
+}
+
 // SetCanManageMessages 站长授予/撤销站点消息管理权限（不可操作站长账号与自己）
 func (s *AdminUserService) SetCanManageMessages(operator *Actor, targetID uint, enabled bool) (*AdminUserItem, error) {
 	if operator == nil || operator.Role != model.RoleOwner {
@@ -564,12 +619,12 @@ func normalizeAuditPage(page, size int) (int, int) {

 // AdminUserAuditProfile 站长查看用户档案摘要
 type AdminUserAuditProfile struct {
-	User            AdminUserItem `json:"user"`
-	PostsTotal      int64         `json:"posts_total"`      // 含各状态与软删
-	CommentsTotal   int64         `json:"comments_total"`   // 含各状态与软删
-	MessagesTotal   int64         `json:"messages_total"`   // 含撤回与软删
-	PublishedPosts  int64         `json:"published_posts"`
-	PublishedComments int64       `json:"published_comments"`
+	User              AdminUserItem `json:"user"`
+	PostsTotal        int64         `json:"posts_total"`    // 含各状态与软删
+	CommentsTotal     int64         `json:"comments_total"` // 含各状态与软删
+	MessagesTotal     int64         `json:"messages_total"` // 含撤回与软删
+	PublishedPosts    int64         `json:"published_posts"`
+	PublishedComments int64         `json:"published_comments"`
 }

 // AdminAuditPostItem 审计帖子行
@@ -594,6 +649,8 @@ type AdminAuditCommentItem struct {
 	Deleted   bool       `json:"deleted"`
 	CreatedAt time.Time  `json:"created_at"`
 	DeletedAt *time.Time `json:"deleted_at,omitempty"`
+	Floor     uint       `json:"floor"`
+	IsRoot    bool       `json:"is_root"`
 }

 // AdminAuditMessageItem 审计聊天消息行
@@ -686,6 +743,11 @@ func (s *AdminUserService) ListAuditComments(actor *Actor, userID uint, page, si
 		Offset((page - 1) * size).Limit(size).Find(&comments).Error; err != nil {
 		return nil, 0, page, err
 	}
+	commentIDs := make([]uint, 0, len(comments))
+	for _, c := range comments {
+		commentIDs = append(commentIDs, c.ID)
+	}
+	anchors := CommentAnchors(s.db, commentIDs)
 	items := make([]AdminAuditCommentItem, 0, len(comments))
 	for _, c := range comments {
 		it := AdminAuditCommentItem{
@@ -695,6 +757,10 @@ func (s *AdminUserService) ListAuditComments(actor *Actor, userID uint, page, si
 			Status:    c.Status,
 			CreatedAt: c.CreatedAt,
 		}
+		if a, ok := anchors[c.ID]; ok {
+			it.Floor = a.Floor
+			it.IsRoot = a.IsRoot
+		}
 		if c.DeletedAt.Valid {
 			it.Deleted = true
 			t := c.DeletedAt.Time
--- a/backend/service/auth.go
+++ b/backend/service/auth.go
@@ -107,10 +107,13 @@ var dummyPasswordHash, _ = bcrypt.GenerateFromPassword(
 	[]byte("j13-dummy-password-for-constant-timing"), bcrypt.DefaultCost)

 // Register 用户注册（事务 + 咨询锁，保证空库至多一名 owner）
+// 邮箱非空时全库唯一（忽略大小写）：后期支持邮箱登录，一邮箱只能对应一个账号
 func (s *AuthService) Register(username, email, password string) (*model.User, error) {
 	if err := NewOperations(s.db, nil).Filter("username", username, 0); err != nil {
 		return nil, err
 	}
+	// 邮箱统一小写归一化，避免大小写变体重复注册
+	email = strings.ToLower(strings.TrimSpace(email))

 	hashed, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
 	if err != nil {
@@ -130,6 +133,16 @@ func (s *AuthService) Register(username, email, password string) (*model.User, e
 		if count > 0 {
 			return errors.New("用户名已被使用")
 		}
+		// 邮箱唯一（忽略大小写，兜底防绕过；入口发码处已拦一次）
+		if email != "" {
+			var emailCount int64
+			if err := tx.Model(&model.User{}).Where("LOWER(email) = ?", email).Count(&emailCount).Error; err != nil {
+				return err
+			}
+			if emailCount > 0 {
+				return errors.New("该邮箱已被注册")
+			}
+		}
 		var n int64
 		if err := tx.Model(&model.User{}).Count(&n).Error; err != nil {
 			return err
@@ -681,14 +694,14 @@ func (s *AuthService) UpdateProfile(userID uint, nickname, email, signature stri
 	if nickCount > 0 {
 		return nil, errors.New("该昵称已被使用")
 	}
-	email = strings.TrimSpace(email)
+	email = strings.ToLower(strings.TrimSpace(email))
 	if email != "" {
 		if !strings.Contains(email, "@") || len(email) > 128 {
 			return nil, errors.New("邮箱格式不正确")
 		}
-		// 邮箱唯一性校验（排除自身）
+		// 邮箱唯一性校验（忽略大小写，排除自身），与注册口径一致
 		var count int64
-		s.db.Model(&model.User{}).Where("email = ? AND id <> ?", email, userID).Count(&count)
+		s.db.Model(&model.User{}).Where("LOWER(email) = ? AND id <> ?", email, userID).Count(&count)
 		if count > 0 {
 			return nil, errors.New("该邮箱已被使用")
 		}
--- a/backend/service/blob_dedup_test.go
+++ b/backend/service/blob_dedup_test.go
@@ -0,0 +1,223 @@
+package service
+
+import (
+	"bytes"
+	"image"
+	"image/color"
+	"image/jpeg"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/freefire/jiang13-bbs/model"
+	webpenc "github.com/gen2brain/webp"
+	"github.com/glebarez/sqlite"
+	"gorm.io/gorm"
+)
+
+func newBlobTestDB(t *testing.T) *gorm.DB {
+	t.Helper()
+	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
+	if err != nil {
+		t.Fatalf("open sqlite: %v", err)
+	}
+	if err := db.AutoMigrate(
+		&model.Blob{}, &model.Attachment{}, &model.PostAttachment{},
+		&model.User{}, &model.Post{},
+	); err != nil {
+		t.Fatalf("migrate: %v", err)
+	}
+	return db
+}
+
+func webpFixtureBytes() []byte {
+	src := image.NewRGBA(image.Rect(0, 0, 20, 10))
+	src.Set(0, 0, color.RGBA{10, 20, 30, 255})
+	var buf bytes.Buffer
+	_ = webpenc.Encode(&buf, src, webpenc.Options{Quality: ImageWebPQuality})
+	return buf.Bytes()
+}
+
+func TestSaveImageBlobDedupAndRefcount(t *testing.T) {
+	db := newBlobTestDB(t)
+	dir := t.TempDir()
+	s := NewUploadService(db, dir)
+	if err := s.EnsureDir(); err != nil {
+		t.Fatalf("ensure dir: %v", err)
+	}
+	data := webpFixtureBytes()
+
+	att1, err := s.SaveImage(1, bytes.NewReader(data), "post")
+	if err != nil {
+		t.Fatalf("SaveImage 1: %v", err)
+	}
+	att2, err := s.SaveImage(2, bytes.NewReader(data), "post")
+	if err != nil {
+		t.Fatalf("SaveImage 2: %v", err)
+	}
+	if att1.URL != att2.URL || att1.BlobHash == "" || att1.BlobHash != att2.BlobHash {
+		t.Fatalf("identical content should share url/hash: %q vs %q", att1.URL, att2.URL)
+	}
+
+	var blob model.Blob
+	if err := db.First(&blob, "hash = ? AND public = ?", att1.BlobHash, true).Error; err != nil {
+		t.Fatalf("load blob: %v", err)
+	}
+	if blob.RefCount != 2 {
+		t.Fatalf("refcount want 2, got %d", blob.RefCount)
+	}
+	blobPath := filepath.Join(dir, filepath.FromSlash(att1.URL[len("/uploads/"):]))
+	if fi, err := os.Stat(blobPath); err != nil || fi.IsDir() {
+		t.Fatalf("shared physical file missing: %v", err)
+	}
+
+	// 删一个引用：文件保留
+	if err := s.DeleteAttachment(1, att1.ID); err != nil {
+		t.Fatalf("DeleteAttachment 1: %v", err)
+	}
+	db.First(&blob, "hash = ? AND public = ?", att1.BlobHash, true)
+	if blob.RefCount != 1 {
+		t.Fatalf("refcount want 1, got %d", blob.RefCount)
+	}
+	if _, err := os.Stat(blobPath); err != nil {
+		t.Fatalf("blob file should survive while referenced: %v", err)
+	}
+
+	// 最后一个引用删除：文件与 blob 行一起回收
+	if err := s.DeleteAttachment(2, att2.ID); err != nil {
+		t.Fatalf("DeleteAttachment 2: %v", err)
+	}
+	if _, err := os.Stat(blobPath); !os.IsNotExist(err) {
+		t.Fatalf("blob file should be removed after last release, stat err=%v", err)
+	}
+	var n int64
+	db.Model(&model.Blob{}).Where("hash = ? AND public = ?", att1.BlobHash, true).Count(&n)
+	if n != 0 {
+		t.Fatalf("blob row should be gone, count=%d", n)
+	}
+}
+
+func TestSaveImageTranscodedJPEGDedup(t *testing.T) {
+	db := newBlobTestDB(t)
+	dir := t.TempDir()
+	s := NewUploadService(db, dir)
+	if err := s.EnsureDir(); err != nil {
+		t.Fatalf("ensure dir: %v", err)
+	}
+
+	src := image.NewRGBA(image.Rect(0, 0, 48, 36))
+	src.Set(1, 2, color.RGBA{200, 100, 50, 255})
+	var in bytes.Buffer
+	if err := jpeg.Encode(&in, src, nil); err != nil {
+		t.Fatalf("encode jpeg: %v", err)
+	}
+
+	att1, err := s.SaveImage(1, bytes.NewReader(in.Bytes()), "post")
+	if err != nil {
+		t.Fatalf("SaveImage 1: %v", err)
+	}
+	att2, err := s.SaveImage(1, bytes.NewReader(in.Bytes()), "post")
+	if err != nil {
+		t.Fatalf("SaveImage 2: %v", err)
+	}
+	// hash 必须对转码后的字节计算：同源 JPEG 两次上传应命中同一个 WebP blob
+	if att1.URL != att2.URL || att1.BlobHash != att2.BlobHash {
+		t.Fatalf("transcoded JPEG should dedup: %q(%s) vs %q(%s)", att1.URL, att1.BlobHash, att2.URL, att2.BlobHash)
+	}
+}
+
+func TestSaveDraftFileBlobDedupAndRefcount(t *testing.T) {
+	db := newBlobTestDB(t)
+	root := t.TempDir()
+	s := NewPostFileService(db, root)
+	if err := s.EnsureDir(); err != nil {
+		t.Fatalf("ensure dir: %v", err)
+	}
+	data := []byte("paid attachment content v1")
+
+	a1, err := s.SaveDraftFile(1, "report.pdf", bytes.NewReader(data), 50)
+	if err != nil {
+		t.Fatalf("SaveDraftFile 1: %v", err)
+	}
+	a2, err := s.SaveDraftFile(2, "another-name.pdf", bytes.NewReader(data), 0)
+	if err != nil {
+		t.Fatalf("SaveDraftFile 2: %v", err)
+	}
+	if a1.BlobHash == "" || a1.BlobHash != a2.BlobHash || a1.StoredName != a2.StoredName {
+		t.Fatalf("same bytes should share blob: %+v vs %+v", a1, a2)
+	}
+	// 原始文件名仍各自保留
+	if a1.Name != "report.pdf" || a2.Name != "another-name.pdf" {
+		t.Fatalf("original names not preserved: %q / %q", a1.Name, a2.Name)
+	}
+	blobPath := s.FilePath(a1)
+	if _, err := os.Stat(blobPath); err != nil {
+		t.Fatalf("shared private blob missing: %v", err)
+	}
+
+	var blob model.Blob
+	if err := db.First(&blob, "hash = ? AND public = ?", a1.BlobHash, false).Error; err != nil {
+		t.Fatalf("load private blob: %v", err)
+	}
+	if blob.RefCount != 2 {
+		t.Fatalf("refcount want 2, got %d", blob.RefCount)
+	}
+
+	if err := s.DeleteOwn(1, a1.ID); err != nil {
+		t.Fatalf("DeleteOwn 1: %v", err)
+	}
+	if _, err := os.Stat(blobPath); err != nil {
+		t.Fatalf("private blob should survive with one ref: %v", err)
+	}
+	if err := s.DeleteOwn(2, a2.ID); err != nil {
+		t.Fatalf("DeleteOwn 2: %v", err)
+	}
+	if _, err := os.Stat(blobPath); !os.IsNotExist(err) {
+		t.Fatalf("private blob should be removed after last release, stat err=%v", err)
+	}
+}
+
+func TestBlobPublicPrivateVisibilityIsolation(t *testing.T) {
+	db := newBlobTestDB(t)
+	root := t.TempDir()
+	img := NewUploadService(db, filepath.Join(root, "uploads"))
+	pf := NewPostFileService(db, filepath.Join(root, "private"))
+	if err := img.EnsureDir(); err != nil {
+		t.Fatalf("ensure upload dir: %v", err)
+	}
+	if err := pf.EnsureDir(); err != nil {
+		t.Fatalf("ensure private dir: %v", err)
+	}
+	data := webpFixtureBytes()
+
+	att, err := img.SaveImage(1, bytes.NewReader(data), "post")
+	if err != nil {
+		t.Fatalf("SaveImage: %v", err)
+	}
+	file, err := pf.SaveDraftFile(1, "x.webp", bytes.NewReader(data), 0)
+	if err != nil {
+		t.Fatalf("SaveDraftFile: %v", err)
+	}
+	if att.BlobHash != file.BlobHash {
+		t.Fatalf("test premise: same bytes should produce same hash")
+	}
+
+	// 同字节在公开/私有命名空间各持一条 blob，互不复用，防止越权读取
+	var pubs, privs int64
+	db.Model(&model.Blob{}).Where("hash = ? AND public = ?", att.BlobHash, true).Count(&pubs)
+	db.Model(&model.Blob{}).Where("hash = ? AND public = ?", att.BlobHash, false).Count(&privs)
+	if pubs != 1 || privs != 1 {
+		t.Fatalf("want separate public/private blobs, pubs=%d privs=%d", pubs, privs)
+	}
+	publicPath := filepath.Join(root, "uploads", filepath.FromSlash(att.URL[len("/uploads/"):]))
+	privatePath := pf.FilePath(file)
+	if publicPath == privatePath {
+		t.Fatal("public and private blob must not share a path")
+	}
+	if _, err := os.Stat(publicPath); err != nil {
+		t.Fatalf("public blob missing: %v", err)
+	}
+	if _, err := os.Stat(privatePath); err != nil {
+		t.Fatalf("private blob missing: %v", err)
+	}
+}
--- a/backend/service/blob_store.go
+++ b/backend/service/blob_store.go
@@ -0,0 +1,132 @@
+package service
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"errors"
+	"io"
+	"os"
+	"path/filepath"
+
+	"github.com/freefire/jiang13-bbs/model"
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+)
+
+// 内容寻址存储（content-addressed storage）：
+// 物理文件按【最终存储字节】的 SHA-256 命名，业务行只引用 hash 并各持一份引用计数；
+// 同内容重复上传不再重复落盘/传输，最后一个引用删除时才回收物理文件。
+// 公开与私有是独立命名空间（见 model.Blob 注释）。
+
+// sha256Hex 计算字节的 SHA-256 hex
+func sha256Hex(data []byte) string {
+	sum := sha256.Sum256(data)
+	return hex.EncodeToString(sum[:])
+}
+
+// hashFile 计算文件内容的 SHA-256 hex，整文件流式读取不进内存
+func hashFile(path string) (string, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+	h := sha256.New()
+	if _, err := io.Copy(h, f); err != nil {
+		return "", err
+	}
+	return hex.EncodeToString(h.Sum(nil)), nil
+}
+
+// acquireBlobRef 登记一次 blob 引用：行不存在则创建（计数=1），已存在则计数+1。
+// 并发下靠 (hash, public) 主键冲突重试，保证不丢计数。
+func acquireBlobRef(db *gorm.DB, hash string, public bool, size int, mimeType, objectID string) error {
+	for {
+		var b model.Blob
+		err := db.Where("hash = ? AND public = ?", hash, public).First(&b).Error
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			b = model.Blob{
+				Hash:     hash,
+				Public:   public,
+				RefCount: 1,
+				Size:     size,
+				MIME:     mimeType,
+				ObjectID: objectID,
+			}
+			if err := db.Create(&b).Error; err != nil {
+				if isUniqueConflict(err) {
+					continue // 并发首建：改为走计数+1
+				}
+				return err
+			}
+			return nil
+		}
+		if err != nil {
+			return err
+		}
+		return db.Model(&model.Blob{}).
+			Where("hash = ? AND public = ?", hash, public).
+			UpdateColumn("ref_count", gorm.Expr("ref_count + 1")).Error
+	}
+}
+
+// releaseBlobRef 释放一次 blob 引用。计数归零时删行并返回 last=true 与该行快照
+// （快照里的 ObjectID/Hash 供调用方回收物理对象）。行不存在视为幂等成功。
+func releaseBlobRef(db *gorm.DB, hash string, public bool) (model.Blob, bool, error) {
+	var removed model.Blob
+	var last bool
+	err := db.Transaction(func(tx *gorm.DB) error {
+		var b model.Blob
+		// 行锁：postgres 下 FOR UPDATE 串行化同 blob 的并发释放；sqlite 写事务天然串行
+		if err := tx.Clauses(clause.Locking{Strength: "UPDATE"}).
+			First(&b, "hash = ? AND public = ?", hash, public).Error; err != nil {
+			if errors.Is(err, gorm.ErrRecordNotFound) {
+				return nil
+			}
+			return err
+		}
+		if b.RefCount <= 1 {
+			result := tx.Where("hash = ? AND public = ? AND ref_count <= 1", hash, public).Delete(&model.Blob{})
+			if result.Error != nil {
+				return result.Error
+			}
+			if result.RowsAffected > 0 {
+				removed = b
+				last = true
+			}
+			return nil
+		}
+		return tx.Model(&model.Blob{}).
+			Where("hash = ? AND public = ?", hash, public).
+			UpdateColumn("ref_count", b.RefCount-1).Error
+	})
+	if err != nil {
+		return model.Blob{}, false, err
+	}
+	return removed, last, nil
+}
+
+// placeLocalBlob 把临时文件原子放到内容寻址目标路径：
+// 目标已存在说明同内容已落盘（字节必然一致），直接丢弃源文件；否则整体 rename。
+// src 与 dst 同一路径时不做操作。
+func placeLocalBlob(src, dst string) error {
+	if abs, err := filepath.Abs(src); err == nil {
+		if dstAbs, err := filepath.Abs(dst); err == nil && abs == dstAbs {
+			return nil
+		}
+	}
+	if err := os.MkdirAll(filepath.Dir(dst), 0o755); err != nil {
+		return err
+	}
+	if _, err := os.Stat(dst); err == nil {
+		if src != dst {
+			_ = os.Remove(src)
+		}
+		return nil
+	}
+	if err := os.Rename(src, dst); err != nil {
+		_ = os.Remove(src)
+		return err
+	}
+	return nil
+}
--- a/backend/service/brand.go
+++ b/backend/service/brand.go
@@ -9,16 +9,17 @@ import (

 // 站点品牌与页脚（公开设置，缺省为空）
 const (
-	SettingKeySiteWordmark  = "site_wordmark"
-	SettingKeySiteSlogan    = "site_slogan"
-	SettingKeySiteKeywords  = "site_keywords"
-	SettingKeyLogoLightURL  = "logo_light_url"
-	SettingKeyLogoDarkURL   = "logo_dark_url"
-	SettingKeyFaviconURL    = "favicon_url"
-	SettingKeyFooterLinks   = "footer_links"
-	SettingKeyBrandMark     = "brand_mark"
-	SettingKeyBrandLogoSize = "brand_logo_size"
-	SettingKeyBrandLogoFit  = "brand_logo_fit"
+	SettingKeySiteWordmark       = "site_wordmark"
+	SettingKeySiteSlogan         = "site_slogan"
+	SettingKeySiteKeywords       = "site_keywords"
+	SettingKeyLogoLightURL       = "logo_light_url"
+	SettingKeyLogoDarkURL        = "logo_dark_url"
+	SettingKeyFaviconURL         = "favicon_url"
+	SettingKeyFooterLinks        = "footer_links"
+	SettingKeyBrandMark          = "brand_mark"
+	SettingKeyBrandLogoSize      = "brand_logo_size"
+	SettingKeyBrandLogoFit       = "brand_logo_fit"
+	SettingKeyBrandSloganVisible = "brand_slogan_visible"

 	BrandSlotLight   = "logo_light"
 	BrandSlotDark    = "logo_dark"
@@ -43,6 +44,8 @@ const (
 	BrandLogoSize3x1 = "3x1"
 	BrandLogoSize4x1 = "4x1"
 	BrandLogoSize169 = "16x9"
+	// BrandLogoSizeAuto 原图比例：自由裁剪，页眉图槽按图片原始比例自适应宽度
+	BrandLogoSizeAuto = "auto"

 	BrandLogoFitCover   = "cover"
 	BrandLogoFitContain = "contain"
@@ -114,7 +117,7 @@ func NormalizeBrandLogoSize(raw string) (string, bool) {
 	switch strings.TrimSpace(raw) {
 	case "", BrandLogoSizeSQ:
 		return BrandLogoSizeSQ, true
-	case BrandLogoSize2x1, BrandLogoSize3x1, BrandLogoSize4x1, BrandLogoSize169:
+	case BrandLogoSize2x1, BrandLogoSize3x1, BrandLogoSize4x1, BrandLogoSize169, BrandLogoSizeAuto:
 		return strings.TrimSpace(raw), true
 	default:
 		return "", false
@@ -367,6 +370,15 @@ func (s *SettingService) fillBrand(out *PublicSiteSettings) error {
 			out.BrandLogoFit = f
 		}
 	}
+	sv, found, err := s.getValue(SettingKeyBrandSloganVisible)
+	if err != nil {
+		return err
+	}
+	if found {
+		out.BrandSloganVisible = sv == "true"
+	} else {
+		out.BrandSloganVisible = true
+	}
 	rawLinks, found, err := s.getValue(SettingKeyFooterLinks)
 	if err != nil {
 		return err
@@ -483,6 +495,14 @@ func (s *SettingService) SetBrandLogoFit(raw string) error {
 	return s.putValue(SettingKeyBrandLogoFit, v)
 }

+// SetBrandSloganVisible 控制标语是否在页眉显示；true 为缺省值，存库时删 key 以保持精简。
+func (s *SettingService) SetBrandSloganVisible(visible bool) error {
+	if visible {
+		return s.deleteKey(SettingKeyBrandSloganVisible)
+	}
+	return s.putValue(SettingKeyBrandSloganVisible, "false")
+}
+
 func (s *SettingService) setBrandURL(key, slot, url string) error {
 	u, ok := NormalizeBrandURL(slot, url)
 	if !ok {
--- a/backend/service/chat.go
+++ b/backend/service/chat.go
@@ -75,8 +75,8 @@ type RoomView struct {
 	Joined      bool        `json:"joined"`
 	MyRole      string      `json:"my_role"`
 	UnreadCount int64       `json:"unread_count"`
-	Pinned      bool        `json:"pinned"`      // 对当前用户是否置顶（含大厅强制）
-	PinForced   bool        `json:"pin_forced"`  // 大厅强制置顶，不可取消
+	Pinned      bool        `json:"pinned"`         // 对当前用户是否置顶（含大厅强制）
+	PinForced   bool        `json:"pin_forced"`     // 大厅强制置顶，不可取消
 	Peer        *model.User `json:"peer,omitempty"` // 私聊对方（仅 direct）
 }

@@ -114,6 +114,15 @@ func (s *ChatService) membership(tx *gorm.DB, roomID, userID uint) (*model.ChatR
 	if err != nil {
 		return nil, err
 	}
+	// 过期禁言自动解除：惰性清理，不依赖定时任务
+	if m.Muted && m.MutedUntil != nil && m.MutedUntil.Before(time.Now()) {
+		m.Muted = false
+		m.MutedUntil = nil
+		_ = tx.Model(&model.ChatRoomMember{}).
+			Where("room_id = ? AND user_id = ?", roomID, userID).
+			Select("muted", "muted_until").
+			Updates(map[string]interface{}{"muted": false, "muted_until": nil}).Error
+	}
 	return &m, nil
 }

@@ -122,7 +131,7 @@ func (s *ChatService) Membership(roomID, userID uint) (*model.ChatRoomMember, er
 	return s.membership(s.db, roomID, userID)
 }

-// unreadCounts 批量计算访问者在给定群集合中的未读数（消息 ID 大于已读水位、且排除本人发送）
+// unreadCounts 批量计算访问者在给定群集合中的未读数（消息 ID 大于已读水位、且排除本人发送与系统提示）
 func (s *ChatService) unreadCounts(userID uint, roomIDs []uint) map[uint]int64 {
 	out := make(map[uint]int64)
 	if userID == 0 || len(roomIDs) == 0 {
@@ -132,7 +141,7 @@ func (s *ChatService) unreadCounts(userID uint, roomIDs []uint) map[uint]int64 {
 	s.db.Table("chat_messages AS m").
 		Select("m.room_id AS room_id, count(*) AS cnt").
 		Joins("JOIN chat_room_members AS rm ON rm.room_id = m.room_id AND rm.user_id = ?", userID).
-		Where("m.room_id IN ? AND m.id > rm.last_read_message_id AND m.sender_id <> ? AND m.deleted_at IS NULL AND m.recalled_at IS NULL", roomIDs, userID).
+		Where("m.room_id IN ? AND m.id > rm.last_read_message_id AND m.sender_id <> ? AND m.deleted_at IS NULL AND m.recalled_at IS NULL AND m.is_system = ?", roomIDs, userID, false).
 		Group("m.room_id").
 		Scan(&rows)
 	for _, r := range rows {
@@ -758,44 +767,96 @@ func (s *ChatService) Kick(operatorID, roomID, targetID uint, oversee bool) erro
 	return s.removeMember(roomID, targetID)
 }

-// SetMemberMute 禁言/解禁：群主、群管、全站监管；不可禁言群主或站点站长账号
-func (s *ChatService) SetMemberMute(operatorID, roomID, targetID uint, muted, oversee bool) error {
+// DisplayName 取用户群聊展示名（昵称优先，退回用户名）；用户不存在/封禁时返回空串
+func (s *ChatService) DisplayName(userID uint) string {
+	var u model.User
+	if err := s.db.Select("id", "nickname", "username").First(&u, userID).Error; err != nil {
+		return ""
+	}
+	if u.Nickname != "" {
+		return u.Nickname
+	}
+	return u.Username
+}
+
+// SendSystemMessage 向房间落库一条系统提示消息（sender_id=0，is_system=true）。
+// 只推进房间 updated_at，不推进 last_message_id：系统提示不作为会话预览，
+// 也不参与排序顶置，避免禁言/解禁等管理动作在会话列表伪装成「新消息」。
+// 失败返回 nil + error。
+func (s *ChatService) SendSystemMessage(roomID uint, content string) (*model.ChatMessage, error) {
+	msg := &model.ChatMessage{
+		RoomID:    roomID,
+		SenderID:  0,
+		Content:   content,
+		IsSystem:  true,
+		CreatedAt: time.Now(),
+	}
+	err := s.db.Transaction(func(tx *gorm.DB) error {
+		if err := tx.Create(msg).Error; err != nil {
+			return err
+		}
+		return tx.Model(&model.ChatRoom{}).Where("id = ?", roomID).
+			Update("updated_at", time.Now()).Error
+	})
+	if err != nil {
+		return nil, err
+	}
+	return msg, nil
+}
+
+// SetMemberMute 禁言/解禁：群主、群管、全站监管；不可禁言群主或站点站长账号。
+// duration 为禁言时长；0 表示永久禁言；muted=false 时忽略 duration 并清空 muted_until。
+// 返回目标用户昵称（供广播系统提示使用）。
+func (s *ChatService) SetMemberMute(operatorID, roomID, targetID uint, muted bool, duration time.Duration, oversee bool) (string, error) {
 	room, err := s.getRoom(roomID)
 	if err != nil {
-		return err
+		return "", err
 	}
 	if room.RoomType == model.ChatRoomTypeDirect {
-		return ErrChatOwnerOnly
+		return "", ErrChatOwnerOnly
 	}
 	target, err := s.membership(s.db, roomID, targetID)
 	if err != nil {
-		return err
+		return "", err
 	}
 	if target.Role == model.ChatRoleOwner {
-		return ErrChatCannotMuteOwner
+		return "", ErrChatCannotMuteOwner
 	}
 	var targetUser model.User
-	if err := s.db.Select("role").First(&targetUser, targetID).Error; err != nil {
-		return ErrChatUserGone
+	if err := s.db.Select("role", "nickname", "username").First(&targetUser, targetID).Error; err != nil {
+		return "", ErrChatUserGone
 	}
 	if targetUser.Role == model.RoleOwner {
-		return ErrChatCannotMuteOwner
+		return "", ErrChatCannotMuteOwner
 	}
 	if !oversee {
 		op, err := s.membership(s.db, roomID, operatorID)
 		if err != nil {
-			return err
+			return "", err
 		}
 		if op.Role != model.ChatRoleOwner && op.Role != model.ChatRoleAdmin {
-			return ErrChatMuteDenied
+			return "", ErrChatMuteDenied
 		}
 		if target.Role == model.ChatRoleAdmin && op.Role != model.ChatRoleOwner {
-			return ErrChatMuteDenied
+			return "", ErrChatMuteDenied
 		}
 	}
-	return s.db.Model(&model.ChatRoomMember{}).
+	var mutedUntil *time.Time
+	if muted && duration > 0 {
+		t := time.Now().Add(duration)
+		mutedUntil = &t
+	}
+	if err := s.db.Model(&model.ChatRoomMember{}).
 		Where("room_id = ? AND user_id = ?", roomID, targetID).
-		Select("muted").Update("muted", muted).Error
+		Select("muted", "muted_until").
+		Updates(map[string]interface{}{"muted": muted, "muted_until": mutedUntil}).Error; err != nil {
+		return "", err
+	}
+	targetName := targetUser.Nickname
+	if targetName == "" {
+		targetName = targetUser.Username
+	}
+	return targetName, nil
 }

 // SetMemberRole 仅站点站长可任命/撤销群管理员（admin <-> member）；不可改群主
@@ -970,7 +1031,7 @@ func (s *ChatService) SendMessage(senderID, roomID uint, content string, replyTo
 	if err != nil {
 		return nil, nil, err
 	}
-	if err := s.db.Preload("Sender").First(msg, msg.ID).Error; err != nil {
+	if err := s.db.Preload("Sender").Preload("Sender.Badges.Badge").First(msg, msg.ID).Error; err != nil {
 		return nil, nil, err
 	}
 	for _, uid := range mentionIDs {
@@ -1059,7 +1120,8 @@ func (s *ChatService) ListMessages(userID, roomID, beforeID uint, size int, over
 		q = q.Where("id < ?", beforeID)
 	}
 	var msgs []model.ChatMessage
-	if err := q.Order("id DESC").Limit(size + 1).Preload("Sender").Preload("Recaller").Find(&msgs).Error; err != nil {
+	// Sender.Badges.Badge 嵌套预加载：消息气泡需展示发送者等级与徽章（与成员列表一致）
+	if err := q.Order("id DESC").Limit(size + 1).Preload("Sender").Preload("Sender.Badges.Badge").Preload("Recaller").Find(&msgs).Error; err != nil {
 		return nil, false, err
 	}
 	hasMore := len(msgs) > size
@@ -1088,7 +1150,7 @@ func (s *ChatService) RecallMessage(operatorID, roomID, messageID uint, oversee
 		return nil, false, err
 	}
 	var msg model.ChatMessage
-	if err := s.db.Where("id = ? AND room_id = ?", messageID, roomID).First(&msg).Error; err != nil {
+	if err := s.db.Where("id = ? AND room_id = ?", messageID, roomID).Preload("Sender").First(&msg).Error; err != nil {
 		if errors.Is(err, gorm.ErrRecordNotFound) {
 			return nil, false, ErrChatMsgNotFound
 		}
@@ -1097,6 +1159,10 @@ func (s *ChatService) RecallMessage(operatorID, roomID, messageID uint, oversee
 	if msg.RecalledAt != nil {
 		return &msg, false, nil // 幂等
 	}
+	// 站长的消息禁止群主/群管/站点消息管撤回（仅全站监管可撤回）
+	if msg.Sender.Role == model.RoleOwner && !oversee {
+		return nil, false, ErrChatRecallDenied
+	}
 	if msg.SenderID == operatorID {
 		if !oversee {
 			if _, err := s.membership(s.db, roomID, operatorID); err != nil {
@@ -1115,7 +1181,17 @@ func (s *ChatService) RecallMessage(operatorID, roomID, messageID uint, oversee
 	}
 	msg.RecalledAt = &now
 	msg.RecalledBy = operatorID
-	_ = s.db.Preload("Sender").Preload("Recaller").First(&msg, msg.ID)
+	// 撤回的是房间当前预览消息时，回退 last_message_id 到最近一条未撤回的非系统消息：
+	// 撤回不在会话列表留下「已撤回」预览，也不让房间因此停留在列表前排，避免被当成新消息提醒。
+	var prevID uint
+	_ = s.db.Model(&model.ChatMessage{}).
+		Where("room_id = ? AND deleted_at IS NULL AND recalled_at IS NULL AND is_system = ?", roomID, false).
+		Order("id DESC").Limit(1).
+		Select("id").Row().Scan(&prevID)
+	_ = s.db.Model(&model.ChatRoom{}).
+		Where("id = ? AND last_message_id = ?", roomID, msg.ID).
+		Update("last_message_id", prevID).Error
+	_ = s.db.Preload("Sender").Preload("Sender.Badges.Badge").Preload("Recaller").First(&msg, msg.ID)
 	return &msg, true, nil
 }

@@ -1295,13 +1371,13 @@ func (s *ChatService) MarkRead(userID, roomID, messageID uint) error {
 		Update("last_read_message_id", messageID).Error
 }

-// UnreadSummary 当前用户所有群的未读明细与总数
+// UnreadSummary 当前用户所有群的未读明细与总数（系统提示消息不计入）
 func (s *ChatService) UnreadSummary(userID uint) (int64, []UnreadRoom, error) {
 	var rows []UnreadRoom
 	err := s.db.Table("chat_messages AS m").
 		Select("m.room_id AS room_id, count(*) AS cnt").
 		Joins("JOIN chat_room_members AS rm ON rm.room_id = m.room_id AND rm.user_id = ?", userID).
-		Where("m.id > rm.last_read_message_id AND m.sender_id <> ? AND m.deleted_at IS NULL AND m.recalled_at IS NULL", userID).
+		Where("m.id > rm.last_read_message_id AND m.sender_id <> ? AND m.deleted_at IS NULL AND m.recalled_at IS NULL AND m.is_system = ?", userID, false).
 		Group("m.room_id").
 		Scan(&rows).Error
 	if err != nil {
--- a/backend/service/comment.go
+++ b/backend/service/comment.go
@@ -44,7 +44,7 @@ func IsNecroReply(lastReplyAt time.Time, afterHours int, now time.Time) bool {

 // CommentService 评论服务
 type CommentService struct {
-	db *gorm.DB
+	db      *gorm.DB
 	setting *SettingService
 }

@@ -297,6 +297,80 @@ func (s *CommentService) FloorNumber(postID, commentID uint) int {
 	return FloorNumber(s.db, postID, commentID)
 }

+// CommentAnchor 评论在所属帖子内的相对锚点：
+// Floor=楼层号（含软删/待审占位，口径同 FloorNumber）；IsRoot=true 为主楼，
+// false 为楼中楼（锚点需附带评论 ID 才能精确定位具体回复）。
+type CommentAnchor struct {
+	Floor  uint `json:"floor"`
+	IsRoot bool `json:"is_root"`
+}
+
+// CommentAnchors 批量查询评论锚点（两条 SQL，避免逐行 N+1）；
+// 评论或其主楼已不存在（如整串被彻底删除）时不出现在结果中。
+func CommentAnchors(db *gorm.DB, ids []uint) map[uint]CommentAnchor {
+	out := make(map[uint]CommentAnchor, len(ids))
+	if db == nil || len(ids) == 0 {
+		return out
+	}
+	// Unscoped：软删/待审评论仍占楼层，与 FloorNumber 同口径
+	var targets []model.Comment
+	if err := db.Unscoped().
+		Select("id", "post_id", "parent_id", "root_id", "created_at").
+		Where("id IN ?", ids).Find(&targets).Error; err != nil {
+		return out
+	}
+	rootIDSet := make(map[uint]struct{}, len(targets))
+	for _, c := range targets {
+		rid := c.ID
+		if c.ParentID != nil && c.RootID != nil {
+			rid = *c.RootID
+		}
+		rootIDSet[rid] = struct{}{}
+	}
+	rootIDs := make([]uint, 0, len(rootIDSet))
+	for rid := range rootIDSet {
+		rootIDs = append(rootIDs, rid)
+	}
+	// 每个主楼之前（按 created_at/id 升序）的主楼数即楼层号 - 1
+	type aheadRow struct {
+		RootID uint
+		Ahead  int64
+	}
+	var aheadRows []aheadRow
+	if err := db.Unscoped().Table("comments AS f").
+		Select(`f.id AS root_id,
+			(SELECT COUNT(*) FROM comments c
+			 WHERE c.post_id = f.post_id AND c.parent_id IS NULL
+			   AND (c.created_at < f.created_at
+			        OR (c.created_at = f.created_at AND c.id < f.id))) AS ahead`).
+		Where("f.id IN ? AND f.parent_id IS NULL", rootIDs).
+		Scan(&aheadRows).Error; err != nil {
+		return out
+	}
+	floorByRoot := make(map[uint]uint, len(aheadRows))
+	for _, r := range aheadRows {
+		floorByRoot[r.RootID] = uint(r.Ahead) + 1
+	}
+	for _, c := range targets {
+		isRoot := c.ParentID == nil
+		rid := c.ID
+		if !isRoot && c.RootID != nil {
+			rid = *c.RootID
+		}
+		floor := floorByRoot[rid]
+		if floor == 0 {
+			continue
+		}
+		out[c.ID] = CommentAnchor{Floor: floor, IsRoot: isRoot}
+	}
+	return out
+}
+
+// AnchorsByCommentIDs 见包级 CommentAnchors
+func (s *CommentService) AnchorsByCommentIDs(ids []uint) map[uint]CommentAnchor {
+	return CommentAnchors(s.db, ids)
+}
+
 // applyCommentListVisibility 评论流可见性：published，或 pending 且（作者 / 该板可审）；
 // 软删行：已发布的对所有人占位；待审软删仅作者/可审者可见占位。
 func applyCommentListVisibility(db *gorm.DB, boardID, viewerID uint, actor *Actor) *gorm.DB {
@@ -442,6 +516,8 @@ type UserCommentItem struct {
 	PostID    uint      `json:"post_id"`
 	PostTitle string    `json:"post_title"`
 	Content   string    `json:"content"`
+	Floor     uint      `json:"floor"`   // 所属楼层相对序号（主楼为自身楼层）
+	IsRoot    bool      `json:"is_root"` // 主楼/楼中楼，供前端拼 #comment-{floor}[-r{id}]
 	CreatedAt time.Time `json:"created_at"`
 }

@@ -470,6 +546,17 @@ func (s *CommentService) ListByUser(userID uint, page, size int) ([]UserCommentI
 	if items == nil {
 		items = []UserCommentItem{}
 	}
+	ids := make([]uint, 0, len(items))
+	for _, it := range items {
+		ids = append(ids, it.ID)
+	}
+	anchors := s.AnchorsByCommentIDs(ids)
+	for i := range items {
+		if a, ok := anchors[items[i].ID]; ok {
+			items[i].Floor = a.Floor
+			items[i].IsRoot = a.IsRoot
+		}
+	}
 	return items, total, nil
 }

--- a/backend/service/follow.go
+++ b/backend/service/follow.go
@@ -9,7 +9,7 @@ import (

 // FollowService 关注服务（仅用户；关注时给对方发通知）
 type FollowService struct {
-	db   *gorm.DB
+	db    *gorm.DB
 	notif *NotificationService
 }

--- a/backend/service/friendlink.go
+++ b/backend/service/friendlink.go
@@ -268,8 +268,8 @@ func (s *FriendLinkService) AdminSetStatus(id uint, status, rejectReason string)
 			return err
 		}
 		updates := map[string]interface{}{
-			"status":      status,
-			"updated_at":  time.Now(),
+			"status":        status,
+			"updated_at":    time.Now(),
 			"reject_reason": "",
 		}
 		switch status {
--- a/backend/service/header_nav.go
+++ b/backend/service/header_nav.go
@@ -24,7 +24,7 @@ const (

 // HeaderNavBuiltinKeys 内置菜单 key 白名单（顺序即默认顺序）；
 // 与前端 lib/headerNav.ts 的 HEADER_NAV_BUILTIN_KEYS 保持一致。
-var HeaderNavBuiltinKeys = []string{"home", "leaderboard", "library"}
+var HeaderNavBuiltinKeys = []string{"home", "leaderboard", "library", "snippets"}

 // HeaderNavItem 顶部导航菜单项：
 //
--- a/backend/service/header_nav_test.go
+++ b/backend/service/header_nav_test.go
@@ -25,18 +25,19 @@ func newHeaderNavTestService(t *testing.T) *SettingService {
 func TestHeaderNavDefaultWhenMissing(t *testing.T) {
 	s := newHeaderNavTestService(t)
 	got := s.HeaderNav()
-	if len(got) != 3 ||
+	if len(got) != 4 ||
 		got[0] != (HeaderNavItem{Type: HeaderNavItemBuiltin, Key: "home"}) ||
 		got[1] != (HeaderNavItem{Type: HeaderNavItemBuiltin, Key: "leaderboard"}) ||
-		got[2] != (HeaderNavItem{Type: HeaderNavItemBuiltin, Key: "library"}) {
+		got[2] != (HeaderNavItem{Type: HeaderNavItemBuiltin, Key: "library"}) ||
+		got[3] != (HeaderNavItem{Type: HeaderNavItemBuiltin, Key: "snippets"}) {
 		t.Fatalf("missing row should fall back to builtin defaults, got %+v", got)
 	}
 	pub, err := s.Public()
 	if err != nil {
 		t.Fatal(err)
 	}
-	if len(pub.HeaderNav) != 3 {
-		t.Fatalf("Public().HeaderNav len = %d, want 3", len(pub.HeaderNav))
+	if len(pub.HeaderNav) != 4 {
+		t.Fatalf("Public().HeaderNav len = %d, want 4", len(pub.HeaderNav))
 	}
 }

@@ -133,7 +134,7 @@ func TestNormalizeHeaderNavDedupesBuiltins(t *testing.T) {

 func TestParseHeaderNavJSONTolerant(t *testing.T) {
 	// 坏 JSON 回落默认
-	if got := parseHeaderNavJSON("{bad"); len(got) != 3 {
+	if got := parseHeaderNavJSON("{bad"); len(got) != 4 {
 		t.Fatalf("bad json should fall back to defaults, got %+v", got)
 	}
 	// 空数组 = 全部隐藏
--- a/backend/service/hide_password_cookie.go
+++ b/backend/service/hide_password_cookie.go
@@ -16,8 +16,8 @@ import (
 )

 const (
-	hidePwdCookiePrefix = "j13_hp_"
-	hidePwdCookieMaxAge = 30 * 24 * 3600 // 30 天
+	hidePwdCookiePrefix  = "j13_hp_"
+	hidePwdCookieMaxAge  = 30 * 24 * 3600 // 30 天
 	hidePwdCookieVersion = "1"
 )

--- a/backend/service/image_variants.go
+++ b/backend/service/image_variants.go
@@ -0,0 +1,276 @@
+package service
+
+import (
+	"bytes"
+	"context"
+	"crypto/sha1"
+	"encoding/hex"
+	"errors"
+	"image"
+	_ "image/gif"
+	_ "image/jpeg"
+	_ "image/png"
+	"io"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	webpenc "github.com/gen2brain/webp"
+	"golang.org/x/image/draw"
+	xwebp "golang.org/x/image/webp"
+)
+
+// 公开图片变体：GET /api/img?u=<源图URL>&w=<目标宽>
+// 按宽度白名单实时缩放为 WebP 并持久缓存到 .thumbs/v/，供全站 <img srcset> 消费。
+// 源内容不可变（上传文件名为随机哈希），变体 URL 可被浏览器/CDN 长期 immutable 缓存。
+// GIF/SVG/ICO 与「源宽 ≤ 请求宽」一律原样透传：保动效、保矢量、不放大。
+// 本地源按 mtime 失效；远程对象（/api/media/）ID 即内容，缓存永久有效。
+
+// VariantWebPQuality 变体 WebP 有损质量（与 MediaThumb 一致）
+const VariantWebPQuality = 78
+
+// variantWidths 宽度白名单（与前端 lib/responsiveImage.ts 同值，约 1.5x 步进）
+var variantWidths = []int{48, 96, 160, 256, 384, 512, 768, 1080, 1536, 1920}
+
+// IsVariantWidth 是否白名单精确值（非法尺寸 400，防止被刷任意尺寸）
+func IsVariantWidth(w int) bool {
+	for _, v := range variantWidths {
+		if v == w {
+			return true
+		}
+	}
+	return false
+}
+
+// variantGenLocks 并发生成去重：key=sha1(url).w → 每变体一把锁
+var variantGenLocks sync.Map
+
+// extMIME 扩展名 → MIME（含 SVG/ICO 透传类型）
+func extMIME(ext string) string {
+	switch ext {
+	case ".jpg", ".jpeg":
+		return "image/jpeg"
+	case ".png":
+		return "image/png"
+	case ".webp":
+		return "image/webp"
+	case ".gif":
+		return "image/gif"
+	case ".svg":
+		return "image/svg+xml"
+	case ".ico":
+		return "image/x-icon"
+	}
+	return ""
+}
+
+// variantCacheFile 变体缓存路径：.thumbs/v/<sha1(url)>.w<w>.webp
+func (s *UploadService) variantCacheFile(url string, w int) string {
+	sum := sha1.Sum([]byte(url))
+	name := hex.EncodeToString(sum[:]) + ".w" + strconv.Itoa(w) + ".webp"
+	return filepath.Join(s.dir, ".thumbs", "v", name)
+}
+
+// variantCacheFresh 缓存是否新鲜：本地源按 mtime；远程对象（modTime 零值）只看存在
+func variantCacheFresh(cache string, modTime time.Time) bool {
+	ti, err := os.Stat(cache)
+	if err != nil || ti.IsDir() {
+		return false
+	}
+	return modTime.IsZero() || !ti.ModTime().Before(modTime)
+}
+
+// Variant 返回源图指定宽度的变体字节与 MIME。
+func (s *UploadService) Variant(rawURL string, width int) ([]byte, string, error) {
+	rawURL = strings.TrimSpace(rawURL)
+	if len(rawURL) == 0 || len(rawURL) > 512 {
+		return nil, "", errors.New("无效地址")
+	}
+	if !IsVariantWidth(width) {
+		return nil, "", errors.New("不支持的尺寸")
+	}
+
+	var (
+		srcData []byte // 远程源预读字节（本地源在锁内读取）
+		srcMIME string
+		srcPath string // 本地源绝对路径
+		modTime time.Time
+		remote  bool
+		cache   = s.variantCacheFile(rawURL, width)
+	)
+
+	switch {
+	case strings.HasPrefix(rawURL, "/uploads/"):
+		rel := filepath.Clean(filepath.FromSlash(strings.TrimPrefix(rawURL, "/uploads/")))
+		if filepath.IsAbs(rel) || rel == "." || strings.HasPrefix(rel, "..") {
+			return nil, "", errors.New("无效地址")
+		}
+		dir := filepath.Dir(rel)
+		catOK := false
+		for _, cat := range mediaLibraryCategories {
+			if cat.Dir == dir {
+				catOK = true
+				break
+			}
+		}
+		if !catOK {
+			return nil, "", errors.New("无效地址")
+		}
+		ext := strings.ToLower(filepath.Ext(rel))
+		mime := extMIME(ext)
+		if mime == "" {
+			return nil, "", errors.New("非图片")
+		}
+		srcPath = filepath.Join(s.dir, rel)
+		info, err := os.Stat(srcPath)
+		if err != nil || info.IsDir() {
+			return nil, "", errors.New("文件不存在")
+		}
+		// 动图/矢量/图标：无法或无需光栅缩放，原样透传（不占变体缓存）
+		if ext == ".gif" || ext == ".svg" || ext == ".ico" {
+			data, err := os.ReadFile(srcPath)
+			return data, mime, err
+		}
+		srcMIME = mime
+		modTime = info.ModTime()
+
+	case strings.HasPrefix(rawURL, "/api/media/"):
+		if s.ops == nil {
+			return nil, "", errors.New("无效地址")
+		}
+		id := strings.TrimPrefix(rawURL, "/api/media/")
+		if id == "" || strings.ContainsAny(id, "/?#") || len(id) > 128 {
+			return nil, "", errors.New("无效地址")
+		}
+		remote = true
+		ctx, cancel := context.WithTimeout(context.Background(), 60*time.Second)
+		defer cancel()
+		r, mime, e := s.ops.OpenObject(ctx, id, true)
+		if e != nil {
+			return nil, "", errors.New("文件暂不可用")
+		}
+		defer r.Close()
+		switch mime {
+		case "image/jpeg", "image/png", "image/webp":
+		case "image/gif", "image/svg+xml", "image/x-icon", "image/vnd.microsoft.icon":
+			data, err := io.ReadAll(r)
+			return data, mime, err
+		default:
+			return nil, "", errors.New("非图片")
+		}
+		srcData, e = io.ReadAll(r)
+		if e != nil {
+			return nil, "", e
+		}
+		srcMIME = mime
+
+	default:
+		return nil, "", errors.New("无效地址")
+	}
+
+	// 快速路径：缓存已新鲜直接返回（无锁）
+	if variantCacheFresh(cache, modTime) {
+		if data, err := os.ReadFile(cache); err == nil {
+			return data, "image/webp", nil
+		}
+	}
+
+	// 并发生成去重：同 url+w 只生成一次
+	sum := sha1.Sum([]byte(rawURL))
+	key := hex.EncodeToString(sum[:]) + ".w" + strconv.Itoa(width)
+	mu, _ := variantGenLocks.LoadOrStore(key, &sync.Mutex{})
+	lk := mu.(*sync.Mutex)
+	lk.Lock()
+	defer lk.Unlock()
+
+	// double-check：等锁期间可能已由他人生成
+	if variantCacheFresh(cache, modTime) {
+		if data, err := os.ReadFile(cache); err == nil {
+			return data, "image/webp", nil
+		}
+	}
+
+	if !remote {
+		data, err := os.ReadFile(srcPath)
+		if err != nil {
+			return nil, "", err
+		}
+		srcData = data
+	}
+
+	out, m, err := variantFromBytes(srcData, srcMIME, width)
+	if err != nil {
+		return nil, "", err // 如动图 WebP，调用方回退原图
+	}
+	// 仅 WebP 变体积缓存（小图透传不落盘）；失败仅影响下次重复生成，不阻断响应
+	if m == "image/webp" {
+		_ = atomicWriteFile(cache, out)
+	}
+	return out, m, nil
+}
+
+// variantFromBytes 源字节 → 目标变体：解码失败报错（调用方回退原图）；
+// 源宽 ≤ 目标宽 → 原字节透传（不放大）；否则按目标宽等比缩放为 WebP。
+func variantFromBytes(srcData []byte, srcMIME string, width int) ([]byte, string, error) {
+	img, err := decodeImageBytes(srcData, srcMIME == "image/webp")
+	if err != nil {
+		return nil, "", err
+	}
+	b := img.Bounds()
+	if b.Dx() <= width {
+		return srcData, srcMIME, nil
+	}
+	nh := max(1, b.Dy()*width/b.Dx())
+	dst := scaleImage(img, width, nh)
+	out, err := encodeLossyWebP(dst, VariantWebPQuality)
+	if err != nil {
+		return nil, "", err
+	}
+	return out, "image/webp", nil
+}
+
+// ---------- 与 MediaThumb 共用的图片处理核心 ----------
+
+// decodeImageBytes 解码图片字节；WebP 走 x/image/webp 解码器
+func decodeImageBytes(data []byte, isWebP bool) (image.Image, error) {
+	if isWebP {
+		return xwebp.Decode(bytes.NewReader(data))
+	}
+	img, _, err := image.Decode(bytes.NewReader(data))
+	return img, err
+}
+
+// scaleImage CatmullRom 高质量缩放到指定宽高
+func scaleImage(img image.Image, nw, nh int) *image.RGBA {
+	dst := image.NewRGBA(image.Rect(0, 0, nw, nh))
+	draw.CatmullRom.Scale(dst, dst.Bounds(), img, img.Bounds(), draw.Src, nil)
+	return dst
+}
+
+// encodeLossyWebP 有损 WebP 编码
+func encodeLossyWebP(img image.Image, quality int) ([]byte, error) {
+	var buf bytes.Buffer
+	if err := webpenc.Encode(&buf, img, webpenc.Options{Quality: quality}); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+// atomicWriteFile 临时文件 + rename 原子落盘
+func atomicWriteFile(path string, data []byte) error {
+	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
+		return err
+	}
+	tmp := path + ".partial"
+	if err := os.WriteFile(tmp, data, 0o644); err != nil {
+		return err
+	}
+	if err := os.Rename(tmp, path); err != nil {
+		_ = os.Remove(tmp)
+		return err
+	}
+	return nil
+}
--- a/backend/service/image_variants_test.go
+++ b/backend/service/image_variants_test.go
@@ -0,0 +1,282 @@
+package service
+
+import (
+	"bytes"
+	"image"
+	"image/color"
+	"image/gif"
+	"image/jpeg"
+	"image/png"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/freefire/jiang13-bbs/config"
+	webpenc "github.com/gen2brain/webp"
+	xwebp "golang.org/x/image/webp"
+)
+
+// solidImg 生成渐变纯色测试图
+func solidImg(w, h int) *image.RGBA {
+	src := image.NewRGBA(image.Rect(0, 0, w, h))
+	for y := 0; y < h; y++ {
+		for x := 0; x < w; x++ {
+			src.Set(x, y, color.RGBA{uint8(x % 256), uint8(y % 256), 128, 255})
+		}
+	}
+	return src
+}
+
+// writeVariantSource 把按编码器生成的文件写到 uploads 目录
+func writeVariantSource(t *testing.T, dir, url string, encode func(io.Writer) error) {
+	t.Helper()
+	abs := filepath.Join(dir, filepath.FromSlash(strings.TrimPrefix(url, "/uploads/")))
+	if err := os.MkdirAll(filepath.Dir(abs), 0o755); err != nil {
+		t.Fatalf("mkdir: %v", err)
+	}
+	f, err := os.Create(abs)
+	if err != nil {
+		t.Fatalf("create: %v", err)
+	}
+	defer f.Close()
+	if err := encode(f); err != nil {
+		t.Fatalf("encode: %v", err)
+	}
+}
+
+func encodeJPEG(img image.Image) func(io.Writer) error {
+	return func(w io.Writer) error {
+		return jpeg.Encode(w, img, &jpeg.Options{Quality: 85})
+	}
+}
+
+func encodePNG(img image.Image) func(io.Writer) error {
+	return func(w io.Writer) error {
+		return png.Encode(w, img)
+	}
+}
+
+func encodeWebP(img image.Image) func(io.Writer) error {
+	return func(w io.Writer) error {
+		return webpenc.Encode(w, img, webpenc.Options{Quality: 85})
+	}
+}
+
+func encodeGIF(img image.Image) func(io.Writer) error {
+	return func(w io.Writer) error {
+		return gif.Encode(w, img, nil)
+	}
+}
+
+// decodeVariant 解码返回的 WebP 变体
+func decodeVariant(t *testing.T, data []byte) image.Image {
+	t.Helper()
+	img, err := xwebp.Decode(bytes.NewReader(data))
+	if err != nil {
+		t.Fatalf("decode variant webp: %v", err)
+	}
+	return img
+}
+
+func TestIsVariantWidth(t *testing.T) {
+	if !IsVariantWidth(48) || !IsVariantWidth(1920) {
+		t.Fatal("whitelist endpoints should be valid")
+	}
+	if IsVariantWidth(100) || IsVariantWidth(0) || IsVariantWidth(-48) {
+		t.Fatal("non-whitelist width should be invalid")
+	}
+}
+
+func TestVariantRejectsInvalidInput(t *testing.T) {
+	s, _ := newUploadTestService(t)
+
+	cases := []struct {
+		name string
+		url  string
+		w    int
+	}{
+		{"非法尺寸", "/uploads/images/a.webp", 100},
+		{"路径穿越", "/uploads/images/../../etc/passwd", 96},
+		{"非白名单目录", "/uploads/secret/a.webp", 96},
+		{"非图片扩展名", "/uploads/images/a.txt", 96},
+		{"外部地址", "https://evil.com/a.webp", 96},
+		{"空地址", "", 96},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			if _, _, err := s.Variant(tc.url, tc.w); err == nil {
+				t.Fatal("want error, got nil")
+			}
+		})
+	}
+}
+
+func TestVariantMissingFile(t *testing.T) {
+	s, _ := newUploadTestService(t)
+	if _, _, err := s.Variant("/uploads/images/missing.webp", 96); err == nil {
+		t.Fatal("missing source should error")
+	}
+}
+
+func TestVariantPassthroughSmallImage(t *testing.T) {
+	s, dir := newUploadTestService(t)
+	url := "/uploads/images/small.webp"
+	writeVariantSource(t, dir, url, encodeWebP(solidImg(48, 48)))
+
+	data, m, err := s.Variant(url, 96)
+	if err != nil {
+		t.Fatalf("variant: %v", err)
+	}
+	if m != "image/webp" {
+		t.Fatalf("want webp mime, got %s", m)
+	}
+	src, _ := os.ReadFile(filepath.Join(dir, filepath.FromSlash("images/small.webp")))
+	if !bytes.Equal(data, src) {
+		t.Fatal("small image should be returned byte-for-byte")
+	}
+}
+
+func TestVariantResizesByWidthLandscape(t *testing.T) {
+	s, dir := newUploadTestService(t)
+	url := "/uploads/images/wide.jpg"
+	writeVariantSource(t, dir, url, encodeJPEG(solidImg(1000, 500)))
+
+	data, m, err := s.Variant(url, 384)
+	if err != nil {
+		t.Fatalf("variant: %v", err)
+	}
+	if m != "image/webp" {
+		t.Fatalf("want webp, got %s", m)
+	}
+	b := decodeVariant(t, data).Bounds()
+	if b.Dx() != 384 || b.Dy() != 192 {
+		t.Fatalf("want 384x192, got %dx%d", b.Dx(), b.Dy())
+	}
+}
+
+func TestVariantResizesByWidthPortrait(t *testing.T) {
+	s, dir := newUploadTestService(t)
+	url := "/uploads/images/tall.png"
+	writeVariantSource(t, dir, url, encodePNG(solidImg(500, 1000)))
+
+	data, _, err := s.Variant(url, 256)
+	if err != nil {
+		t.Fatalf("variant: %v", err)
+	}
+	b := decodeVariant(t, data).Bounds()
+	if b.Dx() != 256 || b.Dy() != 512 {
+		t.Fatalf("want 256x512, got %dx%d", b.Dx(), b.Dy())
+	}
+}
+
+func TestVariantPassthroughGIFSVGICO(t *testing.T) {
+	s, dir := newUploadTestService(t)
+
+	cases := []struct {
+		name string
+		url  string
+		mime string
+		body []byte
+	}{
+		{"gif", "/uploads/images/a.gif", "image/gif", nil},
+		{"svg", "/uploads/images/a.svg", "image/svg+xml", []byte("<svg xmlns=\"http://www.w3.org/2000/svg\"></svg>")},
+		{"ico", "/uploads/images/a.ico", "image/x-icon", []byte("\x00\x00\x01\x00")},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			if tc.body != nil {
+				writeVariantSource(t, dir, tc.url, func(w io.Writer) error {
+					_, err := w.Write(tc.body)
+					return err
+				})
+			} else {
+				writeVariantSource(t, dir, tc.url, encodeGIF(solidImg(16, 16)))
+			}
+			data, m, err := s.Variant(tc.url, 96)
+			if err != nil {
+				t.Fatalf("variant: %v", err)
+			}
+			if m != tc.mime {
+				t.Fatalf("want %s, got %s", tc.mime, m)
+			}
+			src, _ := os.ReadFile(filepath.Join(dir, filepath.FromSlash(strings.TrimPrefix(tc.url, "/uploads/"))))
+			if !bytes.Equal(data, src) {
+				t.Fatalf("%s should pass through unchanged", tc.name)
+			}
+		})
+	}
+}
+
+func TestVariantCachedAndReused(t *testing.T) {
+	s, dir := newUploadTestService(t)
+	url := "/uploads/images/cache.jpg"
+	writeVariantSource(t, dir, url, encodeJPEG(solidImg(1000, 500)))
+
+	first, m, err := s.Variant(url, 384)
+	if err != nil {
+		t.Fatalf("first variant: %v", err)
+	}
+	if m != "image/webp" {
+		t.Fatalf("want webp, got %s", m)
+	}
+	cache := s.variantCacheFile(url, 384)
+	if info, err := os.Stat(cache); err != nil || info.IsDir() {
+		t.Fatalf("cache file should exist: %v", err)
+	}
+	second, _, err := s.Variant(url, 384)
+	if err != nil {
+		t.Fatalf("second variant: %v", err)
+	}
+	if !bytes.Equal(first, second) {
+		t.Fatal("cached variant should be byte-identical")
+	}
+}
+
+func TestVariantCacheFreshness(t *testing.T) {
+	_, dir := newUploadTestService(t)
+	cache := filepath.Join(dir, ".thumbs", "v", "x.webp")
+	if err := os.MkdirAll(filepath.Dir(cache), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(cache, []byte("data"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	// 远程对象：modTime 零值，存在即新鲜
+	if !variantCacheFresh(cache, time.Time{}) {
+		t.Fatal("remote cache should be fresh when file exists")
+	}
+	// 本地源：mtime 新于缓存 → 不新鲜
+	future := time.Now().Add(1 * time.Hour)
+	if variantCacheFresh(cache, future) {
+		t.Fatal("cache should be stale vs newer source mtime")
+	}
+}
+
+func TestVariantRemoteRejectsBadID(t *testing.T) {
+	s, _ := newUploadTestService(t)
+	s.ops = NewOperations(s.db, &config.Config{})
+
+	if _, _, err := s.Variant("/api/media/bad/id", 96); err == nil {
+		t.Fatal("id with slash should be rejected")
+	}
+}
+
+func TestVariantRemoteUnavailable(t *testing.T) {
+	s, _ := newUploadTestService(t)
+	s.ops = NewOperations(s.db, &config.Config{})
+
+	// 表不存在/对象不存在：统一对外“暂不可用”，不泄漏细节
+	if _, _, err := s.Variant("/api/media/deadbeef", 96); err == nil {
+		t.Fatal("missing remote object should error")
+	}
+}
+
+func TestVariantRemoteWithoutOps(t *testing.T) {
+	s, _ := newUploadTestService(t)
+	if _, _, err := s.Variant("/api/media/abc", 96); err == nil {
+		t.Fatal("remote url without ops wired should error")
+	}
+}
--- a/backend/service/leaderboard_test.go
+++ b/backend/service/leaderboard_test.go
@@ -38,9 +38,9 @@ func TestEarnedPointsWindowAndExclusions(t *testing.T) {
 		{UserID: a, Delta: 5, Reason: model.PointReasonCheckin, Balance: 5, CreatedAt: now},
 		{UserID: a, Delta: 3, Reason: model.PointReasonReplyReward, Balance: 8, CreatedAt: now},
 		{UserID: a, Delta: 2, Reason: model.PointReasonStreakBonus, Balance: 10, CreatedAt: now.Add(-time.Hour)},
-		{UserID: a, Delta: -3, Reason: model.PointReasonUnlockPost, Balance: 7, CreatedAt: now},         // 支出不计
-		{UserID: users[1].ID, Delta: 8, Reason: model.PointReasonBountyRefund, Balance: 8, CreatedAt: now}, // 退回不计
-		{UserID: users[2].ID, Delta: 5, Reason: model.PointReasonCheckin, Balance: 5, CreatedAt: now},      // 封禁不计
+		{UserID: a, Delta: -3, Reason: model.PointReasonUnlockPost, Balance: 7, CreatedAt: now},                 // 支出不计
+		{UserID: users[1].ID, Delta: 8, Reason: model.PointReasonBountyRefund, Balance: 8, CreatedAt: now},      // 退回不计
+		{UserID: users[2].ID, Delta: 5, Reason: model.PointReasonCheckin, Balance: 5, CreatedAt: now},           // 封禁不计
 		{UserID: d, Delta: 5, Reason: model.PointReasonCheckin, Balance: 5, CreatedAt: weekAgo.Add(-time.Hour)}, // 窗口外
 	}
 	if err := db.Create(&ledgers).Error; err != nil {
--- a/backend/service/legacyimport.go
+++ b/backend/service/legacyimport.go
@@ -102,7 +102,7 @@ type LegacyUserPreview struct {
 	Nickname  string `json:"nickname"`
 	Posts     int    `json:"posts"`
 	Comments  int    `json:"comments"`
-	Exists    bool   `json:"exists"`    // 本站已有同名账号（导入时自动跳过建号）
+	Exists    bool   `json:"exists"` // 本站已有同名账号（导入时自动跳过建号）
 	HasAvatar bool   `json:"has_avatar"`
 }

@@ -142,8 +142,8 @@ type LegacyUserReport struct {

 // LegacyBoardReport 板块导入明细
 type LegacyBoardReport struct {
-	Created int      `json:"created"` // 新建（预检时为「将新建」）
-	Reused  int      `json:"reused"`  // 复用同名已有板块
+	Created int      `json:"created"`         // 新建（预检时为「将新建」）
+	Reused  int      `json:"reused"`          // 复用同名已有板块
 	Names   []string `json:"names,omitempty"` // 新建板块名
 }

@@ -151,7 +151,7 @@ type LegacyBoardReport struct {
 type LegacyPostReport struct {
 	Total          int      `json:"total"`
 	Imported       int      `json:"imported"`
-	Skipped        int      `json:"skipped"` // 已导入过（去重记录）
+	Skipped        int      `json:"skipped"`  // 已导入过（去重记录）
 	Excluded       int      `json:"excluded"` // 手动排除
 	ExcludedDetail []string `json:"excluded_detail,omitempty"`
 	PollsSkipped   int      `json:"polls_skipped"`
@@ -751,19 +751,19 @@ func (s *LegacyImportService) importPosts(oldDB *gorm.DB, boardMap map[uint]uint
 			continue
 		}
 		post := model.Post{
-			BoardID:      boardID,
-			UserID:       authorID,
-			Title:        truncateRunesN(title, 256),
-			Content:      content,
-			Tags:         p.Tags,
-			PostType:     model.NormalizePostType(p.PostType), // question→question，normal→discussion
-			Pinned:       p.Pinned,
-			Recommended:  p.Featured,
-			Status:       model.ContentStatusPublished,
-			LikeCount:    p.LikeCount,
-			ViewCount:    p.ViewCount,
-			CreatedAt:    p.CreatedAt,
-			UpdatedAt:    p.UpdatedAt,
+			BoardID:     boardID,
+			UserID:      authorID,
+			Title:       truncateRunesN(title, 256),
+			Content:     content,
+			Tags:        p.Tags,
+			PostType:    model.NormalizePostType(p.PostType), // question→question，normal→discussion
+			Pinned:      p.Pinned,
+			Recommended: p.Featured,
+			Status:      model.ContentStatusPublished,
+			LikeCount:   p.LikeCount,
+			ViewCount:   p.ViewCount,
+			CreatedAt:   p.CreatedAt,
+			UpdatedAt:   p.UpdatedAt,
 		}
 		if err := s.db.Create(&post).Error; err != nil {
 			out.Failed = append(out.Failed, fmt.Sprintf("%s (写入失败: %v)", title, err))
--- a/backend/service/legacyimport_test.go
+++ b/backend/service/legacyimport_test.go
@@ -136,9 +136,9 @@ func TestLegacyImportSelectiveRun(t *testing.T) {
 	svc, oldPath, avatarZip, imagesZip, adminID, hallMembers := newLegacyTestEnv(t)
 	opts := LegacyImportOptions{
 		WithContent:     true,
-		SkipUserIDs:     map[uint]bool{2: true, 3: true},   // bob / carol 不建号
-		UserTargetNames: map[uint]string{2: "admin"},      // bob 的内容归到已有账号 admin
-		SkipCommentIDs:  map[uint]bool{202: true},          // 排除 alice 在 #101 的评论
+		SkipUserIDs:     map[uint]bool{2: true, 3: true}, // bob / carol 不建号
+		UserTargetNames: map[uint]string{2: "admin"},     // bob 的内容归到已有账号 admin
+		SkipCommentIDs:  map[uint]bool{202: true},        // 排除 alice 在 #101 的评论
 	}
 	rep, err := svc.ImportFromFiles(oldPath, avatarZip, imagesZip, opts, adminID)
 	if err != nil {
@@ -241,8 +241,8 @@ func TestLegacyImportSelectiveRun(t *testing.T) {
 func TestLegacyImportSkipPostCascades(t *testing.T) {
 	svc, oldPath, avatarZip, imagesZip, adminID, _ := newLegacyTestEnv(t)
 	opts := LegacyImportOptions{
-		WithContent:  true,
-		SkipPostIDs:  map[uint]bool{101: true}, // #101 排除 → 其评论 #202 自动跳过
+		WithContent: true,
+		SkipPostIDs: map[uint]bool{101: true}, // #101 排除 → 其评论 #202 自动跳过
 	}
 	rep, err := svc.ImportFromFiles(oldPath, avatarZip, imagesZip, opts, adminID)
 	if err != nil {
--- a/backend/service/library.go
+++ b/backend/service/library.go
@@ -1,10 +1,12 @@
 package service

 import (
+	"bytes"
 	"crypto/rand"
 	"encoding/hex"
 	"errors"
 	"io"
+	"net/http"
 	"os"
 	"path/filepath"
 	"strconv"
@@ -44,7 +46,16 @@ func LibraryExtAllowed(ext string) bool {

 // 写入时显式列出字段（独立 Select 参数，同 sitePageWriteFields）
 var libraryDocWriteFields = []string{
-	"Slug", "Title", "Description", "CoverURL", "Published", "SortOrder", "EntriesAuto",
+	"Slug", "Title", "Description", "CoverURL", "CoverWidth", "CoverHeight",
+	"Published", "SortOrder", "EntriesAuto", "Author", "CreatorID",
+}
+
+// LibraryCreator 条目创建者摘要（仅列表/详情展示所需字段；用户已注销时为 nil）
+type LibraryCreator struct {
+	ID       uint   `json:"id"`
+	Username string `json:"username"`
+	Nickname string `json:"nickname"`
+	Avatar   string `json:"avatar"`
 }

 // LibraryDocDetail 条目 + 文件列表 + 章节树（管理端与公开详情共用）
@@ -53,27 +64,34 @@ type LibraryDocDetail struct {
 	Deleted  bool                   `json:"deleted"` // 软删标记（DeletedAt json:"-" 不出模型）
 	Files    []model.LibraryFile    `json:"files"`
 	Sections []model.LibrarySection `json:"sections"`
+	Creator  *LibraryCreator        `json:"creator,omitempty"` // 创建者摘要（0/已注销=nil）
 }

-// LibraryDocListItem 公开目录条目（不含 description 全文，含文件概要）
+// LibraryDocListItem 公开目录条目（description 纯文本截断，含文件概要）
 type LibraryDocListItem struct {
-	ID        uint                `json:"id"`
-	Slug      string              `json:"slug"`
-	Title     string              `json:"title"`
-	CoverURL  string              `json:"cover_url"`
-	SortOrder int                 `json:"sort_order"`
-	FileCount int                 `json:"file_count"`
-	Files     []model.LibraryFile `json:"files"`
-	CreatedAt time.Time           `json:"created_at"`
-	UpdatedAt time.Time           `json:"updated_at"`
+	ID          uint                `json:"id"`
+	Slug        string              `json:"slug"`
+	Title       string              `json:"title"`
+	Author      string              `json:"author"`
+	Description string              `json:"description"`
+	CoverURL    string              `json:"cover_url"`
+	SortOrder   int                 `json:"sort_order"`
+	FileCount   int                 `json:"file_count"`
+	Files       []model.LibraryFile `json:"files"`
+	Creator     *LibraryCreator     `json:"creator,omitempty"`
+	CreatedAt   time.Time           `json:"created_at"`
+	UpdatedAt   time.Time           `json:"updated_at"`
 }

 // LibraryInput 创建/更新书库条目入参
 type LibraryInput struct {
 	Slug        string `json:"slug"`
 	Title       string `json:"title"`
+	Author      string `json:"author"` // 书籍作者（自由文本，可空）
 	Description string `json:"description"`
 	CoverURL    string `json:"cover_url"`
+	CoverWidth  int    `json:"cover_width"`  // 封面自然宽（0=未知）
+	CoverHeight int    `json:"cover_height"` // 封面自然高（0=未知）
 	Published   *bool  `json:"published"`
 	SortOrder   *int   `json:"sort_order"`
 	EntriesAuto *bool  `json:"entries_auto"` // 全章节条目卡模式（nil=不修改）
@@ -99,6 +117,11 @@ func (in *LibraryInput) normalize() error {
 		return errors.New("标题不能超过 200 字")
 	}

+	in.Author = strings.TrimSpace(in.Author)
+	if utf8.RuneCountInString(in.Author) > 100 {
+		return errors.New("作者不能超过 100 字")
+	}
+
 	in.Description = strings.TrimSpace(in.Description)
 	if utf8.RuneCountInString(in.Description) > libraryDescriptionMax {
 		return errors.New("介绍不能超过 20000 字")
@@ -115,8 +138,17 @@ func (in *LibraryInput) normalize() error {
 func (in *LibraryInput) applyTo(d *model.LibraryDoc) {
 	d.Slug = in.Slug
 	d.Title = in.Title
+	d.Author = in.Author
 	d.Description = in.Description
 	d.CoverURL = in.CoverURL
+	// 封面清空时一并清除尺寸；有封面但未传尺寸时保留 0（前端回退运行时探测）
+	if in.CoverURL == "" {
+		d.CoverWidth = 0
+		d.CoverHeight = 0
+	} else {
+		d.CoverWidth = in.CoverWidth
+		d.CoverHeight = in.CoverHeight
+	}
 	if in.Published != nil {
 		d.Published = *in.Published
 	}
@@ -130,9 +162,10 @@ func (in *LibraryInput) applyTo(d *model.LibraryDoc) {

 // LibraryService 书库服务（条目 CRUD + 文件落盘/下载/预览）
 type LibraryService struct {
-	db      *gorm.DB
-	dir     string // data/library（绝不放 data/uploads：静态目录会按扩展名原样 serve html）
-	setting *SettingService
+	db         *gorm.DB
+	dir        string // data/library（绝不放 data/uploads：静态目录会按扩展名原样 serve html）
+	uploadsDir string // data/uploads：封面回填时解析本地封面图
+	setting    *SettingService
 }

 func NewLibraryService(db *gorm.DB, dataDir string) *LibraryService {
@@ -145,6 +178,12 @@ func (s *LibraryService) WithSetting(setting *SettingService) *LibraryService {
 	return s
 }

+// WithUploadsDir 注入上传根目录（封面回填用：把 /uploads/... 封面 URL 解析为本地文件）
+func (s *LibraryService) WithUploadsDir(uploadsDir string) *LibraryService {
+	s.uploadsDir = uploadsDir
+	return s
+}
+
 func (s *LibraryService) EnsureDir() error {
 	return os.MkdirAll(s.dir, 0o755)
 }
@@ -224,6 +263,7 @@ func (s *LibraryService) attachFiles(docs []model.LibraryDoc) []LibraryDocDetail
 	for _, sec := range sections {
 		secByDoc[sec.DocID] = append(secByDoc[sec.DocID], sec)
 	}
+	creatorByID := s.creatorMap(docs)
 	for _, d := range docs {
 		fs := byDoc[d.ID]
 		if fs == nil {
@@ -233,12 +273,40 @@ func (s *LibraryService) attachFiles(docs []model.LibraryDoc) []LibraryDocDetail
 		if ss == nil {
 			ss = []model.LibrarySection{}
 		}
-		out = append(out, LibraryDocDetail{LibraryDoc: d, Deleted: d.DeletedAt.Valid, Files: fs, Sections: ss})
+		out = append(out, LibraryDocDetail{
+			LibraryDoc: d, Deleted: d.DeletedAt.Valid, Files: fs, Sections: ss,
+			Creator: creatorByID[d.CreatorID],
+		})
 	}
 	return out
 }

-func (s *LibraryService) Create(in *LibraryInput) (*model.LibraryDoc, error) {
+// creatorMap 批量取条目创建者摘要（一条 SQL，避免列表 N+1；已注销用户查不到即缺省）
+func (s *LibraryService) creatorMap(docs []model.LibraryDoc) map[uint]*LibraryCreator {
+	ids := make([]uint, 0, len(docs))
+	seen := map[uint]bool{}
+	for _, d := range docs {
+		if d.CreatorID > 0 && !seen[d.CreatorID] {
+			seen[d.CreatorID] = true
+			ids = append(ids, d.CreatorID)
+		}
+	}
+	if len(ids) == 0 {
+		return map[uint]*LibraryCreator{}
+	}
+	var users []model.User
+	if err := s.db.Select("id, username, nickname, avatar").Where("id IN ?", ids).Find(&users).Error; err != nil {
+		return map[uint]*LibraryCreator{}
+	}
+	m := make(map[uint]*LibraryCreator, len(users))
+	for i := range users {
+		u := &users[i]
+		m[u.ID] = &LibraryCreator{ID: u.ID, Username: u.Username, Nickname: u.Nickname, Avatar: u.Avatar}
+	}
+	return m
+}
+
+func (s *LibraryService) Create(in *LibraryInput, creatorID ...uint) (*model.LibraryDoc, error) {
 	if err := in.normalize(); err != nil {
 		return nil, err
 	}
@@ -253,6 +321,9 @@ func (s *LibraryService) Create(in *LibraryInput) (*model.LibraryDoc, error) {
 		return nil, errors.New("该地址已被已删除条目占用，可在书库管理列表中彻底删除后重新使用")
 	}
 	d := &model.LibraryDoc{Published: false, SortOrder: 0}
+	if len(creatorID) > 0 {
+		d.CreatorID = creatorID[0]
+	}
 	in.applyTo(d)
 	if err := s.db.Select(libraryDocWriteFields).Create(d).Error; err != nil {
 		return nil, err
@@ -279,12 +350,15 @@ func (s *LibraryService) Update(id uint, in *LibraryInput) (*model.LibraryDoc, e
 		return nil, errors.New("该地址已被已删除条目占用，可在书库管理列表中彻底删除后重新使用")
 	}
 	in.applyTo(&d)
-	// map 更新确保 false/空串写入（同 SitePage.Update）
+	// map 更新确保 false/空串写入（同 SitePage.Update）；creator_id 创建后不变，不在此列
 	if err := s.db.Model(&model.LibraryDoc{}).Where("id = ?", d.ID).Updates(map[string]interface{}{
 		"slug":         d.Slug,
 		"title":        d.Title,
+		"author":       d.Author,
 		"description":  d.Description,
 		"cover_url":    d.CoverURL,
+		"cover_width":  d.CoverWidth,
+		"cover_height": d.CoverHeight,
 		"published":    d.Published,
 		"sort_order":   d.SortOrder,
 		"entries_auto": d.EntriesAuto,
@@ -294,6 +368,77 @@ func (s *LibraryService) Update(id uint, in *LibraryInput) (*model.LibraryDoc, e
 	return &d, nil
 }

+// resolveCoverPath 把 /uploads/... 封面 URL 解析为本地绝对路径；外链返回空串
+func (s *LibraryService) resolveCoverPath(coverURL string) (string, bool) {
+	rel := strings.TrimPrefix(strings.TrimSpace(coverURL), "/uploads/")
+	if rel == "" || rel == coverURL || strings.Contains(rel, "..") {
+		return "", false
+	}
+	abs := filepath.Join(s.uploadsDir, filepath.FromSlash(rel))
+	root := filepath.Clean(s.uploadsDir)
+	clean := filepath.Clean(abs)
+	if clean != root && !strings.HasPrefix(clean, root+string(os.PathSeparator)) {
+		return "", false
+	}
+	return clean, true
+}
+
+// measureCoverReader 从图片流读取自然宽高（复用上传层的格式探测与尺寸解码）
+func measureCoverReader(r io.Reader) (w, h int, err error) {
+	data, err := io.ReadAll(r)
+	if err != nil {
+		return 0, 0, err
+	}
+	format, err := detectImageFormat(data)
+	if err != nil {
+		return 0, 0, err
+	}
+	return decodeImageSizeReader(bytes.NewReader(data), format.mime)
+}
+
+// ensureCoverDimensions 若条目有封面但未存自然宽高，则测量并写回库（幂等：已有尺寸直接跳过）。
+// 用于读路径懒回填，避免独立运维接口：首次访问后尺寸即落库，后续 SSR 首帧直接判定横竖版。
+func (s *LibraryService) ensureCoverDimensions(d *model.LibraryDoc) {
+	if d.CoverURL == "" || (d.CoverWidth > 0 && d.CoverHeight > 0) || s.uploadsDir == "" {
+		return
+	}
+	url := strings.TrimSpace(d.CoverURL)
+	var reader io.ReadCloser
+	switch {
+	case strings.HasPrefix(url, "/uploads/"):
+		abs, ok := s.resolveCoverPath(url)
+		if !ok {
+			return
+		}
+		f, err := os.Open(abs)
+		if err != nil {
+			return
+		}
+		reader = f
+	case strings.HasPrefix(url, "http://") || strings.HasPrefix(url, "https://"):
+		client := &http.Client{Timeout: 10 * time.Second}
+		resp, err := client.Get(url)
+		if err != nil {
+			return
+		}
+		reader = resp.Body
+	default:
+		return
+	}
+	w, h, err := measureCoverReader(reader)
+	reader.Close()
+	if err != nil || w <= 0 || h <= 0 {
+		return
+	}
+	if err := s.db.Model(d).Updates(map[string]interface{}{
+		"cover_width":  w,
+		"cover_height": h,
+	}).Error; err != nil {
+		return
+	}
+	d.CoverWidth, d.CoverHeight = w, h
+}
+
 func (s *LibraryService) Delete(id uint) error {
 	result := s.db.Delete(&model.LibraryDoc{}, id)
 	if result.Error != nil {
@@ -349,8 +494,9 @@ func (s *LibraryService) ListPublished() ([]LibraryDocListItem, error) {
 	out := make([]LibraryDocListItem, 0, len(details))
 	for _, d := range details {
 		out = append(out, LibraryDocListItem{
-			ID: d.ID, Slug: d.Slug, Title: d.Title, CoverURL: d.CoverURL,
-			SortOrder: d.SortOrder, FileCount: len(d.Files), Files: d.Files,
+			ID: d.ID, Slug: d.Slug, Title: d.Title, Author: d.Author, Description: d.Description,
+			CoverURL: d.CoverURL, SortOrder: d.SortOrder, FileCount: len(d.Files), Files: d.Files,
+			Creator:   d.Creator,
 			CreatedAt: d.CreatedAt, UpdatedAt: d.UpdatedAt,
 		})
 	}
@@ -364,6 +510,8 @@ func (s *LibraryService) GetPublishedBySlug(slug string) (*LibraryDocDetail, err
 	if err := s.db.Where("slug = ? AND published = ?", slug, true).First(&d).Error; err != nil {
 		return nil, ErrLibraryNotFound
 	}
+	// 懒回填：有封面但未存尺寸时当场测量并写回（首次访问后即稳定，消除横竖版探测闪烁）
+	s.ensureCoverDimensions(&d)
 	out := s.attachFiles([]model.LibraryDoc{d})
 	return &out[0], nil
 }
--- a/backend/service/library_export.go
+++ b/backend/service/library_export.go
@@ -0,0 +1,369 @@
+package service
+
+// 书库导出：单本 / 全部条目打包为 ZIP（JSON 清单 + 章节正文 + 附件原文件 + 本地封面），
+// 用于迁移与备份。清单自描述（format + format_version），为将来的导入功能预留。
+//
+// 单本 ZIP 布局：
+//
+//	book.json            书籍清单（元信息 / 章节树 / 附件清单，路径均相对本目录）
+//	cover.<ext>          本地封面（外链封面不内嵌，仅保留 cover_url）
+//	files/<stored-name>  附件原文件
+//
+// 全库 ZIP 布局：
+//
+//	library.json                 索引（每本书的目录位置）
+//	docs/<slug>/book.json        各书清单
+//	docs/<slug>/cover.<ext>
+//	docs/<slug>/files/<stored-name>
+
+import (
+	"archive/zip"
+	"bytes"
+	"encoding/json"
+	"errors"
+	"io"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/freefire/jiang13-bbs/model"
+)
+
+const (
+	libraryExportFormat     = "jiang13-library"      // 全库包
+	libraryExportBookFormat = "jiang13-library-book" // 单本书包
+	libraryExportVersion    = 1
+)
+
+// 可内嵌进导出包的本地封面扩展名（与上传层支持的图片格式保持一致）
+var libraryExportCoverExts = map[string]struct{}{
+	"jpg": {}, "jpeg": {}, "png": {}, "gif": {}, "webp": {},
+}
+
+// libraryExportFile 附件清单条目
+type libraryExportFile struct {
+	Name          string `json:"name"`             // 原始文件名
+	Stored        string `json:"stored,omitempty"` // ZIP 内相对路径（磁盘缺失时为空）
+	Ext           string `json:"ext"`
+	MIME          string `json:"mime"`
+	Size          int    `json:"size"`
+	DownloadCount int    `json:"download_count"`
+	SortOrder     int    `json:"sort_order"`
+	Missing       bool   `json:"missing,omitempty"` // 数据库有记录但磁盘文件已丢失
+}
+
+// libraryExportSection 章节清单条目（两级树：ParentKey 指向章的 Key）
+type libraryExportSection struct {
+	Key       string `json:"key"`
+	ParentKey string `json:"parent_key,omitempty"`
+	Title     string `json:"title"`
+	Content   string `json:"content"`
+	SortOrder int    `json:"sort_order"`
+}
+
+// libraryExportBook 单本书的完整清单
+type libraryExportBook struct {
+	ID          uint   `json:"id"`
+	CreatedAt   string `json:"created_at"`
+	UpdatedAt   string `json:"updated_at"`
+	Slug        string `json:"slug"`
+	Title       string `json:"title"`
+	Author      string `json:"author"`
+	Description string `json:"description"`
+	CoverURL    string `json:"cover_url"`
+	CoverFile   string `json:"cover_file,omitempty"` // 相对本书目录的内嵌封面路径
+	CoverWidth  int    `json:"cover_width"`
+	CoverHeight int    `json:"cover_height"`
+	Published   bool   `json:"published"`
+	SortOrder   int    `json:"sort_order"`
+	EntriesAuto bool   `json:"entries_auto"`
+
+	Files    []libraryExportFile    `json:"files"`
+	Sections []libraryExportSection `json:"sections"`
+}
+
+// libraryExportIndexEntry 全库索引中的单本概要
+type libraryExportIndexEntry struct {
+	Slug         string `json:"slug"`
+	Title        string `json:"title"`
+	Dir          string `json:"dir"` // 相对 ZIP 根的目录
+	FileCount    int    `json:"file_count"`
+	SectionCount int    `json:"section_count"`
+}
+
+// libraryExportManifest ZIP 根清单：单本包用 Doc，全库包用 Docs 索引
+type libraryExportManifest struct {
+	Format        string                    `json:"format"`
+	FormatVersion int                       `json:"format_version"`
+	ExportedAt    string                    `json:"exported_at"`
+	Doc           *libraryExportBook        `json:"doc,omitempty"`
+	Docs          []libraryExportIndexEntry `json:"docs,omitempty"`
+}
+
+// preparedFile 已打开、待流式拷入 ZIP 的附件
+type preparedFile struct {
+	zipPath string
+	reader  *os.File
+}
+
+// preparedBook 一本书的导出准备结果（清单 + 已打开的文件句柄）
+type preparedBook struct {
+	meta        libraryExportBook
+	dir         string // ZIP 内目录前缀（单本包为空串 = 根目录）
+	coverPath   string // ZIP 内封面路径（空 = 不内嵌）
+	coverReader *os.File
+	files       []preparedFile // 仅磁盘存在的附件
+}
+
+func (b *preparedBook) closeReaders() {
+	if b.coverReader != nil {
+		_ = b.coverReader.Close()
+	}
+	for i := range b.files {
+		_ = b.files[i].reader.Close()
+	}
+}
+
+// LibraryExport 已完成装载、可直接流式写出的导出包
+type LibraryExport struct {
+	Filename   string
+	full       bool
+	exportedAt time.Time
+	books      []preparedBook
+}
+
+// Close 释放导出过程中打开的全部文件句柄
+func (e *LibraryExport) Close() {
+	for i := range e.books {
+		e.books[i].closeReaders()
+	}
+}
+
+// BuildBookExport 装载单本书导出（不存在返回 ErrLibraryNotFound）。
+// 所有失败均发生在写出之前，handler 可安全返回 JSON 错误。
+func (s *LibraryService) BuildBookExport(id uint) (*LibraryExport, error) {
+	d, err := s.Get(id)
+	if err != nil {
+		return nil, err
+	}
+	b, err := s.prepareBook(d, "")
+	if err != nil {
+		return nil, err
+	}
+	name := d.Slug
+	if name == "" {
+		name = "book"
+	}
+	return &LibraryExport{
+		Filename:   name + ".zip",
+		full:       false,
+		exportedAt: time.Now(),
+		books:      []preparedBook{*b},
+	}, nil
+}
+
+// BuildAllExport 装载全库导出（仅在用条目，按 sort_order / id 排序）
+func (s *LibraryService) BuildAllExport() (*LibraryExport, error) {
+	var docs []model.LibraryDoc
+	if err := s.db.Order("sort_order ASC, id ASC").Find(&docs).Error; err != nil {
+		return nil, err
+	}
+	details := s.attachFiles(docs)
+	exp := &LibraryExport{
+		Filename:   "jiang13-library-" + time.Now().Format("20060102-150405") + ".zip",
+		full:       true,
+		exportedAt: time.Now(),
+		books:      make([]preparedBook, 0, len(details)),
+	}
+	for i := range details {
+		// slug 受 [a-z0-9-] 约束，拼接 ZIP 路径无穿越风险；防御性兜底
+		dir := "docs/" + details[i].Slug + "/"
+		if strings.Contains(details[i].Slug, "..") || strings.ContainsAny(details[i].Slug, `/\`) {
+			exp.Close()
+			return nil, errors.New("条目 slug 含非法字符，无法导出")
+		}
+		b, err := s.prepareBook(&details[i], dir)
+		if err != nil {
+			exp.Close()
+			return nil, err
+		}
+		exp.books = append(exp.books, *b)
+	}
+	return exp, nil
+}
+
+// prepareBook 组装单本清单并打开全部待打包文件（dir 为 ZIP 内目录前缀）
+func (s *LibraryService) prepareBook(d *LibraryDocDetail, dir string) (*preparedBook, error) {
+	b := &preparedBook{dir: dir}
+	b.meta = libraryExportBook{
+		ID:          d.ID,
+		CreatedAt:   d.CreatedAt.UTC().Format(time.RFC3339),
+		UpdatedAt:   d.UpdatedAt.UTC().Format(time.RFC3339),
+		Slug:        d.Slug,
+		Title:       d.Title,
+		Author:      d.Author,
+		Description: d.Description,
+		CoverURL:    d.CoverURL,
+		CoverWidth:  d.CoverWidth,
+		CoverHeight: d.CoverHeight,
+		Published:   d.Published,
+		SortOrder:   d.SortOrder,
+		EntriesAuto: d.EntriesAuto,
+		Files:       make([]libraryExportFile, 0, len(d.Files)),
+		Sections:    make([]libraryExportSection, 0, len(d.Sections)),
+	}
+
+	// 章节：按数组序号发 Key，ParentKey 引用父章 Key（attachFiles 已按 sort_order, id 排序）
+	keyByID := make(map[uint]string, len(d.Sections))
+	for i, sec := range d.Sections {
+		keyByID[sec.ID] = "s" + strconv.Itoa(i)
+	}
+	for _, sec := range d.Sections {
+		m := libraryExportSection{
+			Key:       keyByID[sec.ID],
+			Title:     sec.Title,
+			Content:   sec.Content,
+			SortOrder: sec.SortOrder,
+		}
+		if sec.ParentID != nil {
+			m.ParentKey = keyByID[*sec.ParentID]
+		}
+		b.meta.Sections = append(b.meta.Sections, m)
+	}
+
+	// 附件：数据库清单始终保留；磁盘文件存在才打开并记录 ZIP 路径
+	for _, f := range d.Files {
+		m := libraryExportFile{
+			Name:          f.Name,
+			Ext:           f.Ext,
+			MIME:          f.MIME,
+			Size:          f.Size,
+			DownloadCount: f.DownloadCount,
+			SortOrder:     f.SortOrder,
+		}
+		full := filepath.Join(s.dir, f.StoredName)
+		if r, err := os.Open(full); err == nil {
+			m.Stored = "files/" + f.StoredName
+			b.files = append(b.files, preparedFile{zipPath: dir + m.Stored, reader: r})
+		} else {
+			m.Missing = true
+		}
+		b.meta.Files = append(b.meta.Files, m)
+	}
+
+	// 本地封面（/uploads/...）：能解析到磁盘文件则内嵌；外链或缺目录时仅保留 URL
+	if rel, ok := s.resolveCoverPath(d.CoverURL); ok {
+		if ext := coverExtOf(d.CoverURL); ext != "" {
+			if r, err := os.Open(rel); err == nil {
+				b.coverReader = r
+				b.coverPath = dir + "cover." + ext
+				b.meta.CoverFile = "cover." + ext
+			}
+		}
+	}
+	return b, nil
+}
+
+// WriteZip 流式写出 ZIP。调用后文件句柄随之释放；中途的 IO 错误已无法改变 HTTP 状态。
+func (e *LibraryExport) WriteZip(w io.Writer) error {
+	defer e.Close()
+	zw := zip.NewWriter(w)
+
+	index := make([]libraryExportIndexEntry, 0, len(e.books))
+	for i := range e.books {
+		b := &e.books[i]
+		// 全库包每本书在自己的目录内写 book.json；单本包的根清单即 book.json，在循环外写
+		if e.full {
+			if err := writeZipJSON(zw, b.dir+"book.json", b.meta); err != nil {
+				return err
+			}
+		}
+		if b.coverReader != nil {
+			if err := writeZipFile(zw, b.coverPath, b.coverReader); err != nil {
+				return err
+			}
+		}
+		for j := range b.files {
+			if err := writeZipFile(zw, b.files[j].zipPath, b.files[j].reader); err != nil {
+				return err
+			}
+		}
+		index = append(index, libraryExportIndexEntry{
+			Slug:         b.meta.Slug,
+			Title:        b.meta.Title,
+			Dir:          b.dir,
+			FileCount:    len(b.meta.Files),
+			SectionCount: len(b.meta.Sections),
+		})
+	}
+
+	// 单本包根清单为 book.json；全库包根清单为 library.json（各书清单在其目录内）
+	if e.full {
+		root := libraryExportManifest{
+			Format:        libraryExportFormat,
+			FormatVersion: libraryExportVersion,
+			ExportedAt:    e.exportedAt.UTC().Format(time.RFC3339),
+			Docs:          index,
+		}
+		if err := writeZipJSON(zw, "library.json", root); err != nil {
+			return err
+		}
+	} else {
+		root := libraryExportManifest{
+			Format:        libraryExportBookFormat,
+			FormatVersion: libraryExportVersion,
+			ExportedAt:    e.exportedAt.UTC().Format(time.RFC3339),
+			Doc:           &e.books[0].meta,
+		}
+		if err := writeZipJSON(zw, "book.json", root); err != nil {
+			return err
+		}
+	}
+	return zw.Close()
+}
+
+// coverExtOf 从 /uploads/xx.jpg 形式的封面 URL 提取受支持的图片扩展名
+func coverExtOf(coverURL string) string {
+	u := strings.TrimSpace(coverURL)
+	if i := strings.IndexByte(u, '?'); i >= 0 {
+		u = u[:i]
+	}
+	ext := strings.ToLower(strings.TrimPrefix(filepath.Ext(u), "."))
+	if _, ok := libraryExportCoverExts[ext]; !ok {
+		return ""
+	}
+	return ext
+}
+
+// writeZipJSON 写入一个 DEFLATE 压缩的 UTF-8 JSON 条目（关闭 HTML 转义、缩进可读）
+func writeZipJSON(zw *zip.Writer, name string, v any) error {
+	var buf bytes.Buffer
+	enc := json.NewEncoder(&buf)
+	enc.SetEscapeHTML(false)
+	enc.SetIndent("", "  ")
+	if err := enc.Encode(v); err != nil {
+		return err
+	}
+	hdr := &zip.FileHeader{Name: name, Method: zip.Deflate}
+	hdr.SetMode(0o644)
+	f, err := zw.CreateHeader(hdr)
+	if err != nil {
+		return err
+	}
+	_, err = f.Write(buf.Bytes())
+	return err
+}
+
+// writeZipFile 以 STORE 方式原样写入二进制附件（多为已压缩格式，重复 deflate 仅耗 CPU）
+func writeZipFile(zw *zip.Writer, name string, r io.Reader) error {
+	hdr := &zip.FileHeader{Name: name, Method: zip.Store}
+	hdr.SetMode(0o644)
+	f, err := zw.CreateHeader(hdr)
+	if err != nil {
+		return err
+	}
+	_, err = io.Copy(f, r)
+	return err
+}
--- a/backend/service/library_export_test.go
+++ b/backend/service/library_export_test.go
@@ -0,0 +1,199 @@
+package service
+
+import (
+	"archive/zip"
+	"bytes"
+	"encoding/json"
+	"errors"
+	"io"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+// readZipEntry 读取 ZIP 内指定名称的文件内容（不存在返回 nil, false）
+func readZipEntry(t *testing.T, zr *zip.Reader, name string) ([]byte, bool) {
+	t.Helper()
+	for _, f := range zr.File {
+		if f.Name == name {
+			rc, err := f.Open()
+			if err != nil {
+				t.Fatalf("open zip entry %s: %v", name, err)
+			}
+			defer rc.Close()
+			data, err := io.ReadAll(rc)
+			if err != nil {
+				t.Fatalf("read zip entry %s: %v", name, err)
+			}
+			return data, true
+		}
+	}
+	return nil, false
+}
+
+func buildExportZip(t *testing.T, exp *LibraryExport) *zip.Reader {
+	t.Helper()
+	var buf bytes.Buffer
+	if err := exp.WriteZip(&buf); err != nil {
+		t.Fatalf("write zip: %v", err)
+	}
+	zr, err := zip.NewReader(bytes.NewReader(buf.Bytes()), int64(buf.Len()))
+	if err != nil {
+		t.Fatalf("read exported zip: %v", err)
+	}
+	return zr
+}
+
+// seedBookForExport 造一本含章节（章 + 小节）、附件与本地封面的书籍
+func seedBookForExport(t *testing.T, s *LibraryService, uploads string) (docID uint, storedName string) {
+	t.Helper()
+	pub := true
+	doc, err := s.Create(&LibraryInput{Slug: "dao-jia", Title: "道家研究", Author: "老子", Description: "# 介绍"})
+	if err != nil {
+		t.Fatalf("create doc: %v", err)
+	}
+
+	coverDir := filepath.Join(uploads, "images")
+	if err := os.MkdirAll(coverDir, 0o755); err != nil {
+		t.Fatalf("mkdir uploads: %v", err)
+	}
+	coverBytes := encodeJPEGBytes(t, 120, 160)
+	if err := os.WriteFile(filepath.Join(coverDir, "cover.jpg"), coverBytes, 0o644); err != nil {
+		t.Fatalf("write cover: %v", err)
+	}
+	if _, err := s.Update(doc.ID, &LibraryInput{
+		Slug: "dao-jia", Title: "道家研究", Author: "老子", Description: "# 介绍",
+		CoverURL: "/uploads/images/cover.jpg", CoverWidth: 120, CoverHeight: 160,
+		Published: &pub,
+	}); err != nil {
+		t.Fatalf("update cover: %v", err)
+	}
+
+	chapter, err := s.CreateSection(doc.ID, &SectionInput{Title: "第一章", Content: "章正文"})
+	if err != nil {
+		t.Fatalf("create chapter: %v", err)
+	}
+	if _, err := s.CreateSection(doc.ID, &SectionInput{
+		ParentID: &chapter.ID, Title: "小节", Content: "小节正文",
+	}); err != nil {
+		t.Fatalf("create section: %v", err)
+	}
+
+	f, err := s.AddFile(doc.ID, 1, "manual.epub", bytes.NewReader([]byte("EPUB-FILE-BYTES")))
+	if err != nil {
+		t.Fatalf("add file: %v", err)
+	}
+	return doc.ID, f.StoredName
+}
+
+func TestLibraryExportBook(t *testing.T) {
+	s, _ := newLibraryTestService(t)
+	uploads := t.TempDir()
+	s.WithUploadsDir(uploads)
+	docID, storedName := seedBookForExport(t, s, uploads)
+
+	exp, err := s.BuildBookExport(docID)
+	if err != nil {
+		t.Fatalf("build export: %v", err)
+	}
+	defer exp.Close()
+	if exp.Filename != "dao-jia.zip" {
+		t.Fatalf("filename = %q, want dao-jia.zip", exp.Filename)
+	}
+	zr := buildExportZip(t, exp)
+
+	raw, ok := readZipEntry(t, zr, "book.json")
+	if !ok {
+		t.Fatal("缺少 book.json")
+	}
+	var manifest libraryExportManifest
+	if err := json.Unmarshal(raw, &manifest); err != nil {
+		t.Fatalf("parse book.json: %v", err)
+	}
+	if manifest.Format != libraryExportBookFormat || manifest.FormatVersion != libraryExportVersion {
+		t.Fatalf("清单格式异常: %s v%d", manifest.Format, manifest.FormatVersion)
+	}
+	b := manifest.Doc
+	if b == nil {
+		t.Fatal("book.json 缺少 doc")
+	}
+	if b.Title != "道家研究" || b.Slug != "dao-jia" || b.Author != "老子" || !b.Published {
+		t.Fatalf("元信息导出不正确: %+v", b)
+	}
+	if b.CoverFile != "cover.jpg" || b.CoverWidth != 120 || b.CoverHeight != 160 {
+		t.Fatalf("封面信息导出不正确: %+v", b)
+	}
+	if len(b.Sections) != 2 || b.Sections[0].Key != "s0" || b.Sections[1].ParentKey != "s0" {
+		t.Fatalf("章节树导出不正确: %+v", b.Sections)
+	}
+	if len(b.Files) != 1 || b.Files[0].Stored != "files/"+storedName || b.Files[0].Missing {
+		t.Fatalf("附件清单导出不正确: %+v", b.Files)
+	}
+
+	if data, ok := readZipEntry(t, zr, "files/"+storedName); !ok || string(data) != "EPUB-FILE-BYTES" {
+		t.Fatalf("附件内容导出不正确（ok=%v）", ok)
+	}
+	if data, ok := readZipEntry(t, zr, "cover.jpg"); !ok || !bytes.HasPrefix(data, []byte{0xff, 0xd8, 0xff}) {
+		t.Fatalf("封面内容导出不正确（ok=%v）", ok)
+	}
+	// 单本包不应出现全库索引
+	if _, ok := readZipEntry(t, zr, "library.json"); ok {
+		t.Fatal("单本包不应包含 library.json")
+	}
+}
+
+func TestLibraryExportAll(t *testing.T) {
+	s, _ := newLibraryTestService(t)
+	uploads := t.TempDir()
+	s.WithUploadsDir(uploads)
+	docID, storedName := seedBookForExport(t, s, uploads)
+	_ = docID
+
+	exp, err := s.BuildAllExport()
+	if err != nil {
+		t.Fatalf("build all export: %v", err)
+	}
+	defer exp.Close()
+	zr := buildExportZip(t, exp)
+
+	raw, ok := readZipEntry(t, zr, "library.json")
+	if !ok {
+		t.Fatal("缺少 library.json")
+	}
+	var manifest libraryExportManifest
+	if err := json.Unmarshal(raw, &manifest); err != nil {
+		t.Fatalf("parse library.json: %v", err)
+	}
+	if manifest.Format != libraryExportFormat || len(manifest.Docs) != 1 {
+		t.Fatalf("全库索引异常: %+v", manifest)
+	}
+	idx := manifest.Docs[0]
+	if idx.Dir != "docs/dao-jia/" || idx.FileCount != 1 || idx.SectionCount != 2 {
+		t.Fatalf("索引条目异常: %+v", idx)
+	}
+
+	bookRaw, ok := readZipEntry(t, zr, "docs/dao-jia/book.json")
+	if !ok {
+		t.Fatal("缺少 docs/dao-jia/book.json")
+	}
+	var book libraryExportBook
+	if err := json.Unmarshal(bookRaw, &book); err != nil {
+		t.Fatalf("parse nested book.json: %v", err)
+	}
+	if book.Slug != "dao-jia" || book.CoverFile != "cover.jpg" {
+		t.Fatalf("嵌套书籍清单异常: %+v", book)
+	}
+	if _, ok := readZipEntry(t, zr, "docs/dao-jia/files/"+storedName); !ok {
+		t.Fatal("缺少嵌套附件")
+	}
+	if _, ok := readZipEntry(t, zr, "docs/dao-jia/cover.jpg"); !ok {
+		t.Fatal("缺少嵌套封面")
+	}
+}
+
+func TestLibraryExportMissingDoc(t *testing.T) {
+	s, _ := newLibraryTestService(t)
+	if _, err := s.BuildBookExport(999); !errors.Is(err, ErrLibraryNotFound) {
+		t.Fatalf("不存在的条目应返回 ErrLibraryNotFound，got %v", err)
+	}
+}
--- a/backend/service/library_import.go
+++ b/backend/service/library_import.go
@@ -0,0 +1,631 @@
+package service
+
+// 书库导入恢复：解析导出 ZIP（见 library_export.go），在本站重建书籍。
+//
+//   - 单本包（根 book.json，format=jiang13-library-book）与全库包（library.json 索引）
+//   - mode=create（默认）：同 slug 在用条目冲突时跳过该书；软删占用同样拒绝（释放后再来）
+//   - mode=overwrite：覆盖同 slug 在用条目（章节/附件整体替换，元信息按包恢复）
+//   - 附件复用 AddFile（扩展名白名单/大小/20 个上限/随机落盘），磁盘名重新生成但保留下载计数
+//   - 内嵌封面按魔数校验后随机名落盘 uploads/images；外链封面仅保留 URL
+//   - 逐本独立处理：单本书失败不影响包内其他书，结果以报告返回（包本身非法才整体报错）
+
+import (
+	"archive/zip"
+	"bytes"
+	"crypto/rand"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"io"
+	"os"
+	"path"
+	"path/filepath"
+	"strings"
+
+	"github.com/freefire/jiang13-bbs/model"
+	"gorm.io/gorm"
+)
+
+// LibraryImportMaxBytes 导入 ZIP 上传上限（超出由 handler 提前拦截）
+const LibraryImportMaxBytes = 512 << 20
+
+const (
+	LibraryImportModeCreate    = "create"    // 冲突跳过
+	LibraryImportModeOverwrite = "overwrite" // 冲突覆盖
+)
+
+// 失败原因（前端据此区分冲突，可提示覆盖重导）
+const (
+	libraryImportReasonConflict = "conflict" // slug 被在用条目占用（create 模式）
+	libraryImportReasonDeleted  = "deleted"  // slug 被已软删条目占用
+	libraryImportReasonInvalid  = "invalid"  // 清单数据非法
+	libraryImportReasonFailed   = "failed"   // 落盘/写库失败
+)
+
+var (
+	ErrLibraryImportBadZip = errors.New("无法读取导入文件，请上传书库导出的 ZIP 备份包")
+	ErrLibraryImportFormat = errors.New("不是有效的书库导出包：缺少清单文件或清单已损坏")
+	ErrLibraryImportVer    = errors.New("导出版本不受支持")
+	ErrLibraryImportEmpty  = errors.New("备份包内没有可导入的书籍")
+	ErrLibraryImportMode   = errors.New("无效的导入模式")
+)
+
+// LibraryImportItem 成功导入的单本结果
+type LibraryImportItem struct {
+	Slug     string `json:"slug"`
+	Title    string `json:"title"`
+	Action   string `json:"action"` // created / overwritten
+	Sections int    `json:"sections"`
+	Files    int    `json:"files"`
+}
+
+// LibraryImportFailure 单本书失败明细
+type LibraryImportFailure struct {
+	Slug   string `json:"slug"`
+	Title  string `json:"title"`
+	Reason string `json:"reason"`
+	Error  string `json:"error"`
+}
+
+// LibraryImportReport 导入报告
+type LibraryImportReport struct {
+	Mode     string                 `json:"mode"`
+	Total    int                    `json:"total"`
+	Imported []LibraryImportItem    `json:"imported"`
+	Failed   []LibraryImportFailure `json:"failed"`
+}
+
+// bookImportPlan 单本书的导入计划（清单 + ZIP 内目录前缀）
+type bookImportPlan struct {
+	book libraryExportBook
+	dir  string
+}
+
+// plannedSection 重建后的章节（保留原始 key 用于两级映射；sort 为同层级序号）
+type plannedSection struct {
+	key       string
+	parentKey string
+	title     string
+	content   string
+	sort      int
+}
+
+// ImportLibraryZip 从导出 ZIP 恢复书籍。zipPath 为已落盘的临时文件路径。
+func (s *LibraryService) ImportLibraryZip(zipPath, mode string, userID uint) (*LibraryImportReport, error) {
+	if mode != LibraryImportModeCreate && mode != LibraryImportModeOverwrite {
+		return nil, ErrLibraryImportMode
+	}
+	zr, err := zip.OpenReader(zipPath)
+	if err != nil {
+		return nil, ErrLibraryImportBadZip
+	}
+	defer zr.Close()
+
+	entries := make(map[string]*zip.File, len(zr.File))
+	for _, f := range zr.File {
+		if f.FileInfo().IsDir() {
+			continue
+		}
+		entries[strings.ReplaceAll(f.Name, "\\", "/")] = f // 正常包无重名
+	}
+
+	plans, err := parseImportPlans(entries)
+	if err != nil {
+		return nil, err
+	}
+	if len(plans) == 0 {
+		return nil, ErrLibraryImportEmpty
+	}
+
+	rep := &LibraryImportReport{
+		Mode:     mode,
+		Total:    len(plans),
+		Imported: []LibraryImportItem{},
+		Failed:   []LibraryImportFailure{},
+	}
+	imp := &bookImporter{s: s, entries: entries, userID: userID}
+	for _, p := range plans {
+		item, fail := imp.run(p, mode)
+		if fail != nil {
+			rep.Failed = append(rep.Failed, *fail)
+		} else {
+			rep.Imported = append(rep.Imported, *item)
+		}
+	}
+	return rep, nil
+}
+
+// parseImportPlans 识别单本/全库包并解析书籍清单（不读正文/附件）
+func parseImportPlans(entries map[string]*zip.File) ([]bookImportPlan, error) {
+	if rootRaw, ok := entries["library.json"]; ok {
+		var root libraryExportManifest
+		if err := readZipJSON(rootRaw, &root); err != nil {
+			return nil, ErrLibraryImportFormat
+		}
+		if root.Format != libraryExportFormat || root.FormatVersion != libraryExportVersion {
+			return nil, ErrLibraryImportVer
+		}
+		plans := make([]bookImportPlan, 0, len(root.Docs))
+		for _, d := range root.Docs {
+			dir := strings.ReplaceAll(d.Dir, "\\", "/")
+			if !safeImportDir(dir) {
+				return nil, ErrLibraryImportFormat
+			}
+			raw, ok := entries[path.Clean(dir)+"/book.json"]
+			if !ok {
+				return nil, ErrLibraryImportFormat
+			}
+			var b libraryExportBook
+			if err := readZipJSON(raw, &b); err != nil {
+				return nil, ErrLibraryImportFormat
+			}
+			plans = append(plans, bookImportPlan{book: b, dir: dir})
+		}
+		return plans, nil
+	}
+	if rootRaw, ok := entries["book.json"]; ok {
+		var root libraryExportManifest
+		if err := readZipJSON(rootRaw, &root); err != nil {
+			return nil, ErrLibraryImportFormat
+		}
+		if root.Format != libraryExportBookFormat || root.FormatVersion != libraryExportVersion || root.Doc == nil {
+			return nil, ErrLibraryImportVer
+		}
+		return []bookImportPlan{{book: *root.Doc, dir: ""}}, nil
+	}
+	return nil, ErrLibraryImportFormat
+}
+
+// safeImportDir 全库包内目录必须是 docs/<slug>/ 形态（slug 与条目同规则）
+func safeImportDir(dir string) bool {
+	if dir == "" || !strings.HasPrefix(dir, "docs/") || !strings.HasSuffix(dir, "/") {
+		return false
+	}
+	slug := strings.TrimSuffix(strings.TrimPrefix(dir, "docs/"), "/")
+	if strings.Contains(slug, "/") || strings.Contains(slug, "..") {
+		return false
+	}
+	return sitePageSlugRe.MatchString(slug)
+}
+
+// bookImporter 携带一次批量导入的共享上下文
+type bookImporter struct {
+	s       *LibraryService
+	entries map[string]*zip.File
+	userID  uint
+}
+
+func (imp *bookImporter) fail(p bookImportPlan, reason, msg string) *LibraryImportFailure {
+	return &LibraryImportFailure{Slug: p.book.Slug, Title: p.book.Title, Reason: reason, Error: msg}
+}
+
+// run 导入单本书；返回 item 或 failure（二者互斥）
+func (imp *bookImporter) run(p bookImportPlan, mode string) (*LibraryImportItem, *LibraryImportFailure) {
+	b := p.book
+
+	in, err := buildImportInput(&b)
+	if err != nil {
+		return nil, imp.fail(p, libraryImportReasonInvalid, err.Error())
+	}
+	sections, err := buildImportSections(&b)
+	if err != nil {
+		return nil, imp.fail(p, libraryImportReasonInvalid, err.Error())
+	}
+	if err := imp.checkPlannedFiles(p); err != nil {
+		return nil, imp.fail(p, libraryImportReasonInvalid, err.Error())
+	}
+	coverEntry, err := imp.planCover(p)
+	if err != nil {
+		return nil, imp.fail(p, libraryImportReasonInvalid, err.Error())
+	}
+
+	active, deleted, err := imp.s.slugTaken(b.Slug, 0)
+	if err != nil {
+		return nil, imp.fail(p, libraryImportReasonFailed, "查询条目失败")
+	}
+
+	var docID uint
+	action := "created"
+	var oldFiles []model.LibraryFile // overwrite 时待删磁盘附件
+	var oldCoverDisk string          // overwrite 时待删旧封面（仅本地 /uploads）
+	backfillCreator := false         // overwrite 且原条目无创建者时补记导入操作人
+	switch {
+	case active && mode != LibraryImportModeOverwrite:
+		return nil, imp.fail(p, libraryImportReasonConflict, "slug 已被在用条目占用："+b.Slug)
+	case active:
+		var existing model.LibraryDoc
+		if err := imp.s.db.Where("slug = ?", b.Slug).First(&existing).Error; err != nil {
+			return nil, imp.fail(p, libraryImportReasonFailed, "读取原条目失败")
+		}
+		docID = existing.ID
+		// 跨站恢复不导出创建者：原条目无创建者时把本次导入操作人补为创建者
+		backfillCreator = existing.CreatorID == 0
+		_ = imp.s.db.Where("doc_id = ?", docID).Find(&oldFiles).Error
+		if disk, ok := imp.s.resolveCoverPath(existing.CoverURL); ok {
+			oldCoverDisk = disk
+		}
+		action = "overwritten"
+	case deleted:
+		return nil, imp.fail(p, libraryImportReasonDeleted,
+			"该地址被已删除条目占用，请先在书库管理中彻底删除后再导入："+b.Slug)
+	}
+
+	// 内嵌封面先落盘（URL 在事务前确定；create 失败时随条目回滚删除）
+	coverDisk := ""
+	if coverEntry != nil {
+		url, w, h, disk, ferr := imp.materializeCover(coverEntry)
+		if ferr != nil {
+			return nil, imp.fail(p, libraryImportReasonFailed, "封面恢复失败："+ferr.Error())
+		}
+		in.CoverURL, in.CoverWidth, in.CoverHeight, coverDisk = url, w, h, disk
+	}
+	// 无内嵌封面时保留清单原值（外链或原站 /uploads URL）与尺寸
+
+	txErr := imp.s.db.Transaction(func(tx *gorm.DB) error {
+		if action == "created" {
+			d := &model.LibraryDoc{Published: false, SortOrder: 0, CreatorID: imp.userID}
+			in.applyTo(d)
+			if err := tx.Select(libraryDocWriteFields).Create(d).Error; err != nil {
+				return err
+			}
+			docID = d.ID
+		} else {
+			var d model.LibraryDoc
+			if err := tx.First(&d, docID).Error; err != nil {
+				return err
+			}
+			in.applyTo(&d)
+			updates := map[string]interface{}{
+				"slug":         d.Slug,
+				"title":        d.Title,
+				"author":       d.Author,
+				"description":  d.Description,
+				"cover_url":    d.CoverURL,
+				"cover_width":  d.CoverWidth,
+				"cover_height": d.CoverHeight,
+				"published":    d.Published,
+				"sort_order":   d.SortOrder,
+				"entries_auto": d.EntriesAuto,
+			}
+			if backfillCreator {
+				updates["creator_id"] = imp.userID
+			}
+			if err := tx.Model(&model.LibraryDoc{}).Where("id = ?", d.ID).Updates(updates).Error; err != nil {
+				return err
+			}
+			if err := tx.Unscoped().Where("doc_id = ?", docID).Delete(&model.LibrarySection{}).Error; err != nil {
+				return err
+			}
+			if err := tx.Unscoped().Where("doc_id = ?", docID).Delete(&model.LibraryFile{}).Error; err != nil {
+				return err
+			}
+		}
+		return imp.createSections(tx, docID, sections)
+	})
+	if txErr != nil {
+		if action == "created" && coverDisk != "" {
+			_ = os.Remove(coverDisk)
+		}
+		return nil, imp.fail(p, libraryImportReasonFailed, "写入数据库失败："+txErr.Error())
+	}
+
+	// overwrite 事务成功后清理旧附件与旧封面磁盘文件（失败不影响结果）
+	for i := range oldFiles {
+		_ = os.Remove(imp.s.FilePath(&oldFiles[i]))
+	}
+	if oldCoverDisk != "" && oldCoverDisk != coverDisk {
+		_ = os.Remove(oldCoverDisk)
+	}
+
+	// 附件落盘。create 阶段失败需硬删新建条目以释放 slug；overwrite 仅报告失败
+	added := 0
+	var newFiles []model.LibraryFile
+	for _, mf := range b.Files {
+		if mf.Missing || mf.Stored == "" {
+			continue // 导出时磁盘已丢失的附件：清单保留记录但无文件可恢复
+		}
+		f, fail := imp.addPlannedFile(p, docID, mf)
+		if fail != nil {
+			if action == "created" {
+				imp.rollbackCreated(docID, newFiles, coverDisk)
+			}
+			return nil, fail
+		}
+		newFiles = append(newFiles, *f)
+		added++
+	}
+
+	return &LibraryImportItem{
+		Slug:     b.Slug,
+		Title:    b.Title,
+		Action:   action,
+		Sections: len(sections),
+		Files:    added,
+	}, nil
+}
+
+// ---------- 清单解析与预检 ----------
+
+func buildImportInput(b *libraryExportBook) (*LibraryInput, error) {
+	pub, sortOrder, entriesAuto := b.Published, b.SortOrder, b.EntriesAuto
+	in := &LibraryInput{
+		Slug:        b.Slug,
+		Title:       b.Title,
+		Author:      b.Author,
+		Description: b.Description,
+		CoverURL:    b.CoverURL,
+		CoverWidth:  b.CoverWidth,
+		CoverHeight: b.CoverHeight,
+		Published:   &pub,
+		SortOrder:   &sortOrder,
+		EntriesAuto: &entriesAuto,
+	}
+	if err := in.normalize(); err != nil {
+		return nil, err
+	}
+	return in, nil
+}
+
+// buildImportSections 两轮解析：先章（编号）后节（按父分组编号），校验标题/正文/父引用
+func buildImportSections(b *libraryExportBook) ([]plannedSection, error) {
+	if len(b.Sections) > MaxSectionsPerDoc {
+		return nil, errors.New("章节数量超过上限（最多 200）")
+	}
+	keySeen := map[string]bool{}
+	out := make([]plannedSection, 0, len(b.Sections))
+
+	chapterSort := map[string]int{}
+	order := 0
+	for _, sec := range b.Sections {
+		if sec.ParentKey != "" {
+			continue
+		}
+		title := strings.TrimSpace(sec.Title)
+		if title == "" {
+			return nil, errors.New("存在标题为空的章节")
+		}
+		if err := validateSectionText(title, sec.Content); err != nil {
+			return nil, err
+		}
+		if keySeen[sec.Key] {
+			return nil, errors.New("章节标识重复：" + sec.Key)
+		}
+		keySeen[sec.Key] = true
+		chapterSort[sec.Key] = order
+		out = append(out, plannedSection{
+			key: sec.Key, title: title, content: sec.Content, sort: order,
+		})
+		order++
+	}
+
+	childCount := map[string]int{}
+	for _, sec := range b.Sections {
+		if sec.ParentKey == "" {
+			continue
+		}
+		if _, ok := chapterSort[sec.ParentKey]; !ok {
+			return nil, errors.New("小节「" + strings.TrimSpace(sec.Title) + "」找不到所属章节")
+		}
+		title := strings.TrimSpace(sec.Title)
+		if title == "" {
+			return nil, errors.New("存在标题为空的小节")
+		}
+		if err := validateSectionText(title, sec.Content); err != nil {
+			return nil, err
+		}
+		out = append(out, plannedSection{
+			key:       sec.Key,
+			parentKey: sec.ParentKey,
+			title:     title,
+			content:   sec.Content,
+			sort:      childCount[sec.ParentKey],
+		})
+		childCount[sec.ParentKey]++
+	}
+	return out, nil
+}
+
+func validateSectionText(title, content string) error {
+	if len([]rune(title)) > 200 {
+		return errors.New("章节标题不能超过 200 字：" + title)
+	}
+	if len([]rune(content)) > MaxSectionContent {
+		return errors.New("章节正文不能超过 100000 字：" + title)
+	}
+	return nil
+}
+
+// checkPlannedFiles 预检附件：数量、扩展名、ZIP 路径、声明大小、包内是否存在
+func (imp *bookImporter) checkPlannedFiles(p bookImportPlan) error {
+	if len(p.book.Files) > MaxLibraryFilesPerDoc {
+		return errors.New("附件数量超过上限（最多 20 个）")
+	}
+	maxB := imp.s.maxBytes()
+	for _, f := range p.book.Files {
+		if f.Missing || f.Stored == "" {
+			continue
+		}
+		rel, ok := cleanZipRel(f.Stored)
+		if !ok || !strings.HasPrefix(rel, "files/") {
+			return errors.New("附件路径非法：" + f.Stored)
+		}
+		name := sanitizeFilename(f.Name)
+		if name == "" || !LibraryExtAllowed(ExtOfFilename(name)) {
+			return errors.New("附件格式不受支持：" + f.Name)
+		}
+		zf, ok := imp.entries[p.dir+rel]
+		if !ok {
+			return errors.New("备份包缺少附件文件：" + f.Name)
+		}
+		if zf.UncompressedSize64 > uint64(maxB) {
+			return errors.New("附件超过大小上限：" + f.Name)
+		}
+	}
+	return nil
+}
+
+// planCover 返回内嵌封面 ZIP 条目（无则 nil）
+func (imp *bookImporter) planCover(p bookImportPlan) (*zip.File, error) {
+	cf := strings.TrimSpace(p.book.CoverFile)
+	if cf == "" {
+		return nil, nil
+	}
+	rel, ok := cleanZipRel(cf)
+	if !ok || strings.Contains(rel, "/") {
+		return nil, errors.New("封面路径非法：" + cf)
+	}
+	zf, ok := imp.entries[p.dir+rel]
+	if !ok {
+		return nil, errors.New("备份包缺少封面文件")
+	}
+	if zf.UncompressedSize64 > uint64(ImageMaxBytes) {
+		return nil, errors.New("封面不能超过 5MB")
+	}
+	return zf, nil
+}
+
+// ---------- 落盘 ----------
+
+// createSections 两趟写入：先建章（key→新ID），再建节（父引用映射后的章 ID）
+func (imp *bookImporter) createSections(tx *gorm.DB, docID uint, sections []plannedSection) error {
+	keyToID := make(map[string]uint, len(sections))
+	for i := range sections {
+		ps := &sections[i]
+		if ps.parentKey != "" {
+			continue
+		}
+		sec := &model.LibrarySection{DocID: docID, Title: ps.title, Content: ps.content, SortOrder: ps.sort}
+		if err := tx.Create(sec).Error; err != nil {
+			return err
+		}
+		keyToID[ps.key] = sec.ID
+	}
+	for i := range sections {
+		ps := &sections[i]
+		if ps.parentKey == "" {
+			continue
+		}
+		parentID, ok := keyToID[ps.parentKey]
+		if !ok {
+			return errors.New("小节找不到所属章节")
+		}
+		sec := &model.LibrarySection{
+			DocID: docID, ParentID: &parentID,
+			Title: ps.title, Content: ps.content, SortOrder: ps.sort,
+		}
+		if err := tx.Create(sec).Error; err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// addPlannedFile 从 ZIP 读取附件并复用 AddFile 落盘，随后恢复下载计数与排序
+func (imp *bookImporter) addPlannedFile(
+	p bookImportPlan, docID uint, mf libraryExportFile,
+) (*model.LibraryFile, *LibraryImportFailure) {
+	rel, _ := cleanZipRel(mf.Stored)
+	zf, ok := imp.entries[p.dir+rel]
+	if !ok {
+		return nil, imp.fail(p, libraryImportReasonFailed, "备份包缺少附件文件："+mf.Name)
+	}
+	rc, err := zf.Open()
+	if err != nil {
+		return nil, imp.fail(p, libraryImportReasonFailed, "读取附件失败："+mf.Name)
+	}
+	defer rc.Close()
+	f, err := imp.s.AddFile(docID, imp.userID, mf.Name, io.LimitReader(rc, imp.s.maxBytes()+1))
+	if err != nil {
+		return nil, imp.fail(p, libraryImportReasonFailed, "附件恢复失败「"+mf.Name+"」："+err.Error())
+	}
+	if err := imp.s.db.Model(&model.LibraryFile{}).Where("id = ?", f.ID).
+		UpdateColumns(map[string]interface{}{
+			"download_count": mf.DownloadCount,
+			"sort_order":     mf.SortOrder,
+		}).Error; err != nil {
+		return nil, imp.fail(p, libraryImportReasonFailed, "附件信息写入失败："+mf.Name)
+	}
+	return f, nil
+}
+
+// materializeCover 校验图片魔数后以随机名落盘 uploads/images，返回 URL/尺寸/磁盘路径
+func (imp *bookImporter) materializeCover(zf *zip.File) (string, int, int, string, error) {
+	if imp.s.uploadsDir == "" {
+		return "", 0, 0, "", errors.New("未配置上传目录")
+	}
+	rc, err := zf.Open()
+	if err != nil {
+		return "", 0, 0, "", err
+	}
+	defer rc.Close()
+	data, err := io.ReadAll(io.LimitReader(rc, ImageMaxBytes+1))
+	if err != nil {
+		return "", 0, 0, "", err
+	}
+	if int64(len(data)) > ImageMaxBytes {
+		return "", 0, 0, "", errors.New("封面不能超过 5MB")
+	}
+	format, err := detectImageFormat(data)
+	if err != nil {
+		return "", 0, 0, "", err
+	}
+	width, height, err := decodeImageSizeReader(bytes.NewReader(data), format.mime)
+	if err != nil || width < 1 || height < 1 {
+		return "", 0, 0, "", errors.New("无法解析封面图片")
+	}
+	if width > ImageMaxDim || height > ImageMaxDim {
+		return "", 0, 0, "", errors.New("封面边长不能超过 4096px")
+	}
+	nameBytes := make([]byte, 16)
+	if _, err := rand.Read(nameBytes); err != nil {
+		return "", 0, 0, "", err
+	}
+	filename := hex.EncodeToString(nameBytes) + format.ext
+	imagesDir := filepath.Join(imp.s.uploadsDir, "images")
+	if err := os.MkdirAll(imagesDir, 0o755); err != nil {
+		return "", 0, 0, "", err
+	}
+	full := filepath.Join(imagesDir, filename)
+	if err := os.WriteFile(full, data, 0o644); err != nil {
+		return "", 0, 0, "", err
+	}
+	return "/uploads/images/" + filename, width, height, full, nil
+}
+
+// rollbackCreated create 模式落盘阶段失败：硬删条目/章节/文件行与已落盘文件，释放 slug
+func (imp *bookImporter) rollbackCreated(docID uint, newFiles []model.LibraryFile, coverDisk string) {
+	_ = imp.s.db.Unscoped().Where("doc_id = ?", docID).Delete(&model.LibrarySection{}).Error
+	_ = imp.s.db.Unscoped().Where("doc_id = ?", docID).Delete(&model.LibraryFile{}).Error
+	_ = imp.s.db.Unscoped().Delete(&model.LibraryDoc{}, docID).Error
+	for i := range newFiles {
+		_ = os.Remove(imp.s.FilePath(&newFiles[i]))
+	}
+	if coverDisk != "" {
+		_ = os.Remove(coverDisk)
+	}
+}
+
+// ---------- ZIP 工具 ----------
+
+// cleanZipRel 校验 ZIP 内相对路径：拒绝绝对路径与任何 ../ 穿越段
+func cleanZipRel(rel string) (string, bool) {
+	p := path.Clean(strings.ReplaceAll(strings.TrimSpace(rel), "\\", "/"))
+	if p == "." || p == "" || path.IsAbs(p) || p == ".." {
+		return "", false
+	}
+	for _, seg := range strings.Split(p, "/") {
+		if seg == ".." {
+			return "", false
+		}
+	}
+	return p, true
+}
+
+func readZipJSON(zf *zip.File, v any) error {
+	rc, err := zf.Open()
+	if err != nil {
+		return err
+	}
+	defer rc.Close()
+	return json.NewDecoder(rc).Decode(v)
+}
--- a/backend/service/library_import_test.go
+++ b/backend/service/library_import_test.go
@@ -0,0 +1,354 @@
+package service
+
+import (
+	"archive/zip"
+	"bytes"
+	"errors"
+	"image"
+	"image/jpeg"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/freefire/jiang13-bbs/model"
+)
+
+func encodeJPEGBytes(t *testing.T, w, h int) []byte {
+	t.Helper()
+	var buf bytes.Buffer
+	if err := jpeg.Encode(&buf, image.NewRGBA(image.Rect(0, 0, w, h)), &jpeg.Options{Quality: 80}); err != nil {
+		t.Fatalf("encode jpeg: %v", err)
+	}
+	return buf.Bytes()
+}
+
+// writeExportZipFile 把内存导出包落盘为临时 zip（模拟 handler 上传后的临时文件）
+func writeExportZipFile(t *testing.T, exp *LibraryExport) string {
+	t.Helper()
+	p := filepath.Join(t.TempDir(), "export.zip")
+	f, err := os.Create(p)
+	if err != nil {
+		t.Fatalf("create temp zip: %v", err)
+	}
+	if err := exp.WriteZip(f); err != nil {
+		t.Fatalf("write export zip: %v", err)
+	}
+	if err := f.Close(); err != nil {
+		t.Fatalf("close temp zip: %v", err)
+	}
+	return p
+}
+
+// writeZipFileMap 手工构造 ZIP（用于非法包测试）
+func writeZipFileMap(t *testing.T, entries map[string]string) string {
+	t.Helper()
+	buf := new(bytes.Buffer)
+	zw := zip.NewWriter(buf)
+	for name, content := range entries {
+		w, err := zw.Create(name)
+		if err != nil {
+			t.Fatalf("zip create %s: %v", name, err)
+		}
+		if _, err := io.WriteString(w, content); err != nil {
+			t.Fatalf("zip write %s: %v", name, err)
+		}
+	}
+	if err := zw.Close(); err != nil {
+		t.Fatalf("zip close: %v", err)
+	}
+	p := filepath.Join(t.TempDir(), "in.zip")
+	if err := os.WriteFile(p, buf.Bytes(), 0o644); err != nil {
+		t.Fatalf("write temp zip: %v", err)
+	}
+	return p
+}
+
+func assertReportOK(t *testing.T, rep *LibraryImportReport, total int) {
+	t.Helper()
+	if rep == nil {
+		t.Fatal("报告为空")
+	}
+	if rep.Total != total {
+		t.Fatalf("total = %d, want %d", rep.Total, total)
+	}
+	if len(rep.Failed) != 0 {
+		t.Fatalf("存在失败记录: %+v", rep.Failed)
+	}
+	if len(rep.Imported) != total {
+		t.Fatalf("imported = %d, want %d", len(rep.Imported), total)
+	}
+}
+
+// TestLibraryImportBookRoundTrip 单本包：导出 → 导入 → 冲突跳过 → 覆盖导入
+func TestLibraryImportBookRoundTrip(t *testing.T) {
+	// ---- 源库 ----
+	src, _ := newLibraryTestService(t)
+	srcUploads := t.TempDir()
+	src.WithUploadsDir(srcUploads)
+	docID, storedName := seedBookForExport(t, src, srcUploads)
+
+	// 制造两次下载，验证计数随包保留
+	var srcFile model.LibraryFile
+	if err := src.db.Where("stored_name = ?", storedName).First(&srcFile).Error; err != nil {
+		t.Fatalf("find source file: %v", err)
+	}
+	src.IncrDownload(srcFile.ID)
+	src.IncrDownload(srcFile.ID)
+
+	exp, err := src.BuildBookExport(docID)
+	if err != nil {
+		t.Fatalf("build export: %v", err)
+	}
+	zipPath := writeExportZipFile(t, exp)
+	exp.Close()
+
+	// ---- 目标库（空库）----
+	dst, _ := newLibraryTestService(t)
+	dstUploads := t.TempDir()
+	dst.WithUploadsDir(dstUploads)
+
+	// 1) create 导入
+	rep, err := dst.ImportLibraryZip(zipPath, LibraryImportModeCreate, 7)
+	if err != nil {
+		t.Fatalf("import: %v", err)
+	}
+	assertReportOK(t, rep, 1)
+	item := rep.Imported[0]
+	if item.Slug != "dao-jia" || item.Action != "created" || item.Sections != 2 || item.Files != 1 {
+		t.Fatalf("导入条目异常: %+v", item)
+	}
+
+	var doc model.LibraryDoc
+	if err := dst.db.Where("slug = ?", "dao-jia").First(&doc).Error; err != nil {
+		t.Fatalf("find imported doc: %v", err)
+	}
+	if doc.Title != "道家研究" || doc.Description != "# 介绍" || !doc.Published {
+		t.Fatalf("元信息恢复不正确: %+v", doc)
+	}
+	if doc.Author != "老子" {
+		t.Fatalf("作者恢复不正确: %q", doc.Author)
+	}
+	if doc.CreatorID != 7 {
+		t.Fatalf("新建导入创建者应为导入操作人，got %d", doc.CreatorID)
+	}
+	if !strings.HasPrefix(doc.CoverURL, "/uploads/images/") || doc.CoverURL == "/uploads/images/cover.jpg" {
+		t.Fatalf("封面 URL 应为重新落盘的随机名，got %q", doc.CoverURL)
+	}
+	if doc.CoverWidth != 120 || doc.CoverHeight != 160 {
+		t.Fatalf("封面尺寸恢复不正确: %dx%d", doc.CoverWidth, doc.CoverHeight)
+	}
+	coverDisk, ok := dst.resolveCoverPath(doc.CoverURL)
+	if !ok {
+		t.Fatalf("封面路径无法解析: %s", doc.CoverURL)
+	}
+	coverData, err := os.ReadFile(coverDisk)
+	if err != nil {
+		t.Fatalf("封面未落盘: %v", err)
+	}
+	if !bytes.HasPrefix(coverData, []byte{0xff, 0xd8, 0xff}) {
+		t.Fatal("封面内容不是 JPEG")
+	}
+
+	// 章节树：章 + 小节父子关系
+	secs, err := dst.ListSections(doc.ID)
+	if err != nil {
+		t.Fatalf("list sections: %v", err)
+	}
+	if len(secs) != 2 {
+		t.Fatalf("章节数 = %d, want 2", len(secs))
+	}
+	var chapter, child *model.LibrarySection
+	for i := range secs {
+		if secs[i].ParentID == nil {
+			chapter = &secs[i]
+		} else {
+			child = &secs[i]
+		}
+	}
+	if chapter == nil || child == nil {
+		t.Fatalf("章节层级不正确: %+v", secs)
+	}
+	if chapter.Title != "第一章" || chapter.SortOrder != 0 {
+		t.Fatalf("章信息不正确: %+v", chapter)
+	}
+	if child.Title != "小节" || *child.ParentID != chapter.ID || child.SortOrder != 0 {
+		t.Fatalf("小节信息不正确: %+v", child)
+	}
+
+	// 附件：重新随机落盘、内容与下载计数保留
+	var files []model.LibraryFile
+	if err := dst.db.Where("doc_id = ?", doc.ID).Find(&files).Error; err != nil {
+		t.Fatalf("list files: %v", err)
+	}
+	if len(files) != 1 {
+		t.Fatalf("附件数 = %d, want 1", len(files))
+	}
+	nf := files[0]
+	if nf.Name != "manual.epub" || nf.DownloadCount != 2 || nf.StoredName == srcFile.StoredName {
+		t.Fatalf("附件恢复不正确: %+v", nf)
+	}
+	data, err := os.ReadFile(dst.FilePath(&nf))
+	if err != nil {
+		t.Fatalf("附件未落盘: %v", err)
+	}
+	if string(data) != "EPUB-FILE-BYTES" {
+		t.Fatalf("附件内容不正确: %q", data)
+	}
+	firstCoverURL := doc.CoverURL
+
+	// 2) 再次 create：冲突跳过
+	rep2, err := dst.ImportLibraryZip(zipPath, LibraryImportModeCreate, 7)
+	if err != nil {
+		t.Fatalf("re-import: %v", err)
+	}
+	if rep2.Total != 1 || len(rep2.Imported) != 0 || len(rep2.Failed) != 1 {
+		t.Fatalf("冲突报告异常: %+v", rep2)
+	}
+	if rep2.Failed[0].Reason != libraryImportReasonConflict {
+		t.Fatalf("失败原因应为 conflict，got %q", rep2.Failed[0].Reason)
+	}
+	var docCount int64
+	dst.db.Model(&model.LibraryDoc{}).Count(&docCount)
+	if docCount != 1 {
+		t.Fatalf("冲突跳过后书库数量异常: %d", docCount)
+	}
+
+	// 3) overwrite：先加一个计划外附件与旧封面，导入后应被整体替换
+	extra, err := dst.AddFile(doc.ID, 7, "extra.txt", bytes.NewReader([]byte("EXTRA-BYTES")))
+	if err != nil {
+		t.Fatalf("add extra: %v", err)
+	}
+	extraPath := dst.FilePath(extra)
+	if _, err := os.Stat(extraPath); err != nil {
+		t.Fatalf("extra 未先落盘: %v", err)
+	}
+
+	rep3, err := dst.ImportLibraryZip(zipPath, LibraryImportModeOverwrite, 7)
+	if err != nil {
+		t.Fatalf("overwrite import: %v", err)
+	}
+	assertReportOK(t, rep3, 1)
+	if rep3.Imported[0].Action != "overwritten" {
+		t.Fatalf("动作应为 overwritten，got %q", rep3.Imported[0].Action)
+	}
+
+	dst.db.Model(&model.LibraryDoc{}).Count(&docCount)
+	if docCount != 1 {
+		t.Fatalf("覆盖后书库数量异常: %d", docCount)
+	}
+	var doc2 model.LibraryDoc
+	if err := dst.db.Where("slug = ?", "dao-jia").First(&doc2).Error; err != nil {
+		t.Fatalf("find overwritten doc: %v", err)
+	}
+	if secs2, err := dst.ListSections(doc2.ID); err != nil || len(secs2) != 2 {
+		t.Fatalf("覆盖后章节异常: %d %v", len(secs2), err)
+	}
+	if doc2.Author != "老子" || doc2.CreatorID != 7 {
+		t.Fatalf("覆盖后作者/创建者异常: author=%q creator=%d", doc2.Author, doc2.CreatorID)
+	}
+	var files2 []model.LibraryFile
+	if err := dst.db.Where("doc_id = ?", doc2.ID).Find(&files2).Error; err != nil || len(files2) != 1 {
+		t.Fatalf("覆盖后附件数量异常: %d %v", len(files2), err)
+	}
+	if files2[0].Name != "manual.epub" || files2[0].DownloadCount != 2 {
+		t.Fatalf("覆盖后附件内容异常: %+v", files2[0])
+	}
+	if _, err := os.Stat(extraPath); !os.IsNotExist(err) {
+		t.Fatalf("旧附件磁盘文件应被删除，err=%v", err)
+	}
+	oldCoverDisk, _ := dst.resolveCoverPath(firstCoverURL)
+	if _, err := os.Stat(oldCoverDisk); !os.IsNotExist(err) {
+		t.Fatalf("旧封面磁盘文件应被删除，err=%v", err)
+	}
+	if doc2.CoverURL == firstCoverURL {
+		t.Fatal("覆盖后封面应重新落盘为新文件")
+	}
+	newCoverDisk, _ := dst.resolveCoverPath(doc2.CoverURL)
+	if _, err := os.ReadFile(newCoverDisk); err != nil {
+		t.Fatalf("新封面未落盘: %v", err)
+	}
+}
+
+// TestLibraryImportAll 全库包往返
+func TestLibraryImportAll(t *testing.T) {
+	src, _ := newLibraryTestService(t)
+	srcUploads := t.TempDir()
+	src.WithUploadsDir(srcUploads)
+	if _, err := src.Create(&LibraryInput{Slug: "second-book", Title: "第二本"}); err != nil {
+		t.Fatalf("create second doc: %v", err)
+	}
+	seedBookForExport(t, src, srcUploads)
+
+	exp, err := src.BuildAllExport()
+	if err != nil {
+		t.Fatalf("build all export: %v", err)
+	}
+	zipPath := writeExportZipFile(t, exp)
+	exp.Close()
+
+	dst, _ := newLibraryTestService(t)
+	dst.WithUploadsDir(t.TempDir())
+	rep, err := dst.ImportLibraryZip(zipPath, LibraryImportModeCreate, 1)
+	if err != nil {
+		t.Fatalf("import all: %v", err)
+	}
+	assertReportOK(t, rep, 2)
+	slugs := map[string]bool{}
+	for _, it := range rep.Imported {
+		slugs[it.Slug] = true
+	}
+	if !slugs["dao-jia"] || !slugs["second-book"] {
+		t.Fatalf("导入书集不正确: %+v", slugs)
+	}
+}
+
+// TestLibraryImportRejectBadPackage 非法包整体拒绝
+func TestLibraryImportRejectBadPackage(t *testing.T) {
+	s, _ := newLibraryTestService(t)
+	s.WithUploadsDir(t.TempDir())
+
+	badPath := filepath.Join(t.TempDir(), "bad.zip")
+	if err := os.WriteFile(badPath, []byte("this is not a zip"), 0o644); err != nil {
+		t.Fatalf("write: %v", err)
+	}
+	if _, err := s.ImportLibraryZip(badPath, LibraryImportModeCreate, 1); !errors.Is(err, ErrLibraryImportBadZip) {
+		t.Fatalf("非 zip 应返回 ErrLibraryImportBadZip，got %v", err)
+	}
+
+	noManifest := writeZipFileMap(t, map[string]string{"files/a.epub": "x"})
+	if _, err := s.ImportLibraryZip(noManifest, LibraryImportModeCreate, 1); !errors.Is(err, ErrLibraryImportFormat) {
+		t.Fatalf("缺清单应返回 ErrLibraryImportFormat，got %v", err)
+	}
+
+	if _, err := s.ImportLibraryZip(badPath, "bogus", 1); !errors.Is(err, ErrLibraryImportMode) {
+		t.Fatalf("非法模式应返回 ErrLibraryImportMode，got %v", err)
+	}
+}
+
+// TestCleanZipRel 路径穿越校验
+func TestCleanZipRel(t *testing.T) {
+	cases := []struct {
+		in   string
+		want bool
+	}{
+		{"", false},
+		{".", false},
+		{"..", false},
+		{"../evil", false},
+		{"a/../../b", false},
+		{"/etc/passwd", false},
+		{`docs\..\..\x`, false},
+		{"files/a.epub", true},
+		{"docs/x/book.json", true},
+		{`docs\x/cover.jpg`, true},
+		{"a//b", true},
+	}
+	for _, tc := range cases {
+		_, ok := cleanZipRel(tc.in)
+		if ok != tc.want {
+			t.Errorf("cleanZipRel(%q) = %v, want %v", tc.in, ok, tc.want)
+		}
+	}
+}
--- a/backend/service/library_test.go
+++ b/backend/service/library_test.go
@@ -18,7 +18,7 @@ func newLibraryTestService(t *testing.T) (*LibraryService, string) {
 	if err != nil {
 		t.Fatalf("open sqlite: %v", err)
 	}
-	if err := db.AutoMigrate(&model.LibraryDoc{}, &model.LibraryFile{}, &model.LibrarySection{}); err != nil {
+	if err := db.AutoMigrate(&model.User{}, &model.LibraryDoc{}, &model.LibraryFile{}, &model.LibrarySection{}); err != nil {
 		t.Fatalf("migrate: %v", err)
 	}
 	dir := t.TempDir()
@@ -45,6 +45,7 @@ func TestLibraryNormalize(t *testing.T) {
 		{"标题为空", func(i *LibraryInput) { i.Title = " " }, "标题不能为空"},
 		{"标题超限", func(i *LibraryInput) { i.Title = strings.Repeat("书", 201) }, "标题不能超过"},
 		{"介绍超限", func(i *LibraryInput) { i.Description = strings.Repeat("介", 20001) }, "介绍不能超过"},
+		{"作者超限", func(i *LibraryInput) { i.Author = strings.Repeat("作", 101) }, "作者不能超过"},
 		{"合法", func(i *LibraryInput) {}, ""},
 	}
 	for _, tc := range cases {
@@ -63,6 +64,58 @@ func TestLibraryNormalize(t *testing.T) {
 	}
 }

+func TestLibraryAuthorAndCreator(t *testing.T) {
+	s, _ := newLibraryTestService(t)
+	user := &model.User{Username: "curator", Nickname: "馆长", Avatar: "/a.png"}
+	if err := s.db.Create(user).Error; err != nil {
+		t.Fatalf("create user: %v", err)
+	}
+
+	pub := true
+	doc, err := s.Create(&LibraryInput{
+		Slug: "authored", Title: "署名本", Author: "  鲁迅  ", Published: &pub,
+	}, user.ID)
+	if err != nil {
+		t.Fatalf("create: %v", err)
+	}
+	if doc.Author != "鲁迅" || doc.CreatorID != user.ID {
+		t.Fatalf("作者应裁剪、创建者应落库，got %+v", doc)
+	}
+
+	list, err := s.ListPublished()
+	if err != nil {
+		t.Fatalf("list: %v", err)
+	}
+	if len(list) != 1 || list[0].Author != "鲁迅" {
+		t.Fatalf("列表作者异常: %+v", list)
+	}
+	if c := list[0].Creator; c == nil || c.ID != user.ID || c.Nickname != "馆长" {
+		t.Fatalf("列表创建者摘要异常: %+v", c)
+	}
+
+	detail, err := s.GetPublishedBySlug("authored")
+	if err != nil {
+		t.Fatalf("detail: %v", err)
+	}
+	if detail.Creator == nil || detail.Creator.Username != "curator" {
+		t.Fatalf("详情创建者摘要异常: %+v", detail.Creator)
+	}
+
+	// 作者可清空；更新不改变创建者归属
+	if _, err := s.Update(doc.ID, &LibraryInput{
+		Slug: "authored", Title: "署名本", Author: "", Published: &pub,
+	}); err != nil {
+		t.Fatalf("update: %v", err)
+	}
+	var again model.LibraryDoc
+	if err := s.db.First(&again, doc.ID).Error; err != nil {
+		t.Fatalf("reload: %v", err)
+	}
+	if again.Author != "" || again.CreatorID != user.ID {
+		t.Fatalf("更新后作者/创建者异常: %+v", again)
+	}
+}
+
 func TestLibrarySlugUnique(t *testing.T) {
 	s, _ := newLibraryTestService(t)
 	if _, err := s.Create(&LibraryInput{Slug: "epub-latest", Title: "A"}); err != nil {
--- a/backend/service/media_library.go
+++ b/backend/service/media_library.go
@@ -30,6 +30,27 @@ var mediaLibraryCategories = []struct {
 	{"brand", "brand", "品牌资源"},
 }

+// 衍生分类：不对应 uploads 子目录，按附件 source 归类
+const (
+	mediaCategoryBook     = "book"
+	mediaCategoryBookName = "书籍"
+)
+
+// mediaCategoryForAttachment 附件在媒体库中的展示分类：
+// 书库封面 / 正文插图（source=library_cover|library_content）统一归“书籍”，
+// 其余按 kind 对应磁盘目录分类。
+func mediaCategoryForAttachment(kind, source string) (key, name string) {
+	if source == model.AttachmentSourceLibraryCover || source == model.AttachmentSourceLibraryContent {
+		return mediaCategoryBook, mediaCategoryBookName
+	}
+	for _, cat := range mediaLibraryCategories {
+		if cat.Key == kind {
+			return cat.Key, cat.Name
+		}
+	}
+	return kind, kind
+}
+
 // MediaLibraryItem 媒体库条目
 type MediaLibraryItem struct {
 	URL          string     `json:"url"`                    // 展示地址（有 WebP 时为 WebP）
@@ -43,6 +64,7 @@ type MediaLibraryItem struct {
 	Height       int        `json:"height"`
 	Uploader     string     `json:"uploader,omitempty"` // 上传者昵称（取自附件记录，无记录为空）
 	UploadedAt   *time.Time `json:"uploaded_at,omitempty"`
+	RefCount     int        `json:"ref_count,omitempty"`    // 引用计数（>1 表示内容相同的重复上传共享此文件）
 	SourceURL    string     `json:"source_url,omitempty"`   // 来源回链（帖子/评论锚点/用户主页）
 	SourceLabel  string     `json:"source_label,omitempty"` // 来源描述（如：帖子《…》下的评论）
 }
@@ -53,6 +75,7 @@ func (s *UploadService) AdminMediaLibrary() ([]MediaLibraryItem, map[string]int,
 	// 附件元数据索引：URL → 记录（联出上传者昵称）
 	type attMeta struct {
 		Kind      string
+		Source    string
 		URL       string
 		MIME      string
 		Size      int
@@ -64,41 +87,49 @@ func (s *UploadService) AdminMediaLibrary() ([]MediaLibraryItem, map[string]int,
 	}
 	var rows []attMeta
 	if err := s.db.Table("attachments").
-		Select("attachments.kind, attachments.url, attachments.mime, attachments.size, attachments.width, attachments.height, attachments.created_at, users.nickname, users.username").
+		Select("attachments.kind, attachments.source, attachments.url, attachments.mime, attachments.size, attachments.width, attachments.height, attachments.created_at, users.nickname, users.username").
 		Joins("LEFT JOIN users ON users.id = attachments.user_id").
 		Scan(&rows).Error; err != nil {
 		return nil, nil, err
 	}
-	metaByURL := make(map[string]attMeta, len(rows))
-	// 远程存储对象（/api/media/）不在磁盘上，直接作为条目加入
-	items := make([]MediaLibraryItem, 0, len(rows))
-	categoryName := func(key string) string {
-		for _, cat := range mediaLibraryCategories {
-			if cat.Key == key {
-				return cat.Name
-			}
-		}
-		return key
+	// 同 URL 多条记录（内容寻址去重后，重复上传共享同一文件）：
+	// 上传者/时间取最早一条，计数即该文件的引用次数
+	type urlMeta struct {
+		meta  attMeta
+		count int
 	}
+	agg := make(map[string]*urlMeta, len(rows))
 	for _, r := range rows {
-		metaByURL[r.URL] = r // 本地文件在磁盘扫描时按 URL 合并元数据
-		if !strings.HasPrefix(r.URL, "/api/media/") {
-			continue
+		if a, ok := agg[r.URL]; ok {
+			a.count++
+			if r.CreatedAt.Before(a.meta.CreatedAt) {
+				a.meta = r
+			}
+		} else {
+			agg[r.URL] = &urlMeta{meta: r, count: 1}
+		}
+	}
+	// 远程存储对象（/api/media/）不在磁盘上，按 URL 去重后直接作为条目加入
+	items := make([]MediaLibraryItem, 0, len(agg))
+	for url, a := range agg {
+		r := a.meta
+		if !strings.HasPrefix(url, "/api/media/") {
+			continue // 本地文件在磁盘扫描时按 URL 合并元数据
+		}
+		if r.Kind != model.AttachmentKindImage && r.Kind != model.AttachmentKindAvatar {
+			continue // 未知 kind 不进媒体库
 		}
 		uploader := r.Nickname
 		if uploader == "" {
 			uploader = r.Username
 		}
-		cat := r.Kind
-		if cat != model.AttachmentKindImage && cat != model.AttachmentKindAvatar {
-			continue // 未知 kind 不进媒体库
-		}
+		catKey, catName := mediaCategoryForAttachment(r.Kind, r.Source)
 		ca := r.CreatedAt
 		items = append(items, MediaLibraryItem{
-			URL: r.URL, Category: cat, CategoryName: categoryName(cat),
-			Name: strings.TrimPrefix(r.URL, "/api/media/"), MIME: r.MIME,
+			URL: url, Category: catKey, CategoryName: catName,
+			Name: strings.TrimPrefix(url, "/api/media/"), MIME: r.MIME,
 			Size: int64(r.Size), Width: r.Width, Height: r.Height,
-			Uploader: uploader, UploadedAt: &ca,
+			Uploader: uploader, UploadedAt: &ca, RefCount: a.count,
 		})
 	}

@@ -138,8 +169,9 @@ func (s *UploadService) AdminMediaLibrary() ([]MediaLibraryItem, map[string]int,
 				mt := info.ModTime()
 				item.UploadedAt = &mt
 			}
-			if m, ok := metaByURL[url]; ok {
+			if a, ok := agg[url]; ok {
 				// 附件记录有上传者与准确创建时间，覆盖磁盘信息
+				m := a.meta
 				uploader := m.Nickname
 				if uploader == "" {
 					uploader = m.Username
@@ -147,12 +179,18 @@ func (s *UploadService) AdminMediaLibrary() ([]MediaLibraryItem, map[string]int,
 				ca := m.CreatedAt
 				item.Uploader = uploader
 				item.UploadedAt = &ca
+				item.RefCount = a.count
 				if m.Size > 0 {
 					item.Size = int64(m.Size)
 				}
 				if m.Width > 0 {
 					item.Width, item.Height = m.Width, m.Height
 				}
+				// 书库封面 / 正文插图改归“书籍”分类
+				if m.Source == model.AttachmentSourceLibraryCover || m.Source == model.AttachmentSourceLibraryContent {
+					item.Category = mediaCategoryBook
+					item.CategoryName = mediaCategoryBookName
+				}
 			}
 			// 无尺寸记录时读图片头解析宽高（失败不阻断，保持 0）
 			if item.Width == 0 && item.Size > 0 && item.Size <= 20<<20 {
@@ -243,6 +281,8 @@ func (s *UploadService) attachMediaSources(items []MediaLibraryItem) {
 	postByURL := map[string]postRef{}
 	type commentRef struct {
 		id, postID uint
+		floor      uint
+		isRoot     bool
 	}
 	commentByURL := map[string]commentRef{}

@@ -299,6 +339,19 @@ func (s *UploadService) attachMediaSources(items []MediaLibraryItem) {
 		}
 	}

+	// 评论锚点改用所属帖内相对楼层号（#comment-{floor}，楼中楼追加 -r{id}）
+	commentIDs := make([]uint, 0, len(commentByURL))
+	for _, cm := range commentByURL {
+		commentIDs = append(commentIDs, cm.id)
+	}
+	commentAnchors := CommentAnchors(s.db, commentIDs)
+	for u, cm := range commentByURL {
+		if a, ok := commentAnchors[cm.id]; ok {
+			cm.floor, cm.isRoot = a.Floor, a.IsRoot
+			commentByURL[u] = cm
+		}
+	}
+
 	// 评论来源要带宿主帖子标题，一次性补齐
 	postTitle := func(id uint) string {
 		var p model.Post
@@ -374,7 +427,15 @@ func (s *UploadService) attachMediaSources(items []MediaLibraryItem) {
 				break
 			}
 			if cm, ok := commentByURL[u]; ok {
-				it.SourceURL = fmt.Sprintf("/post/%d#comment-%d", cm.postID, cm.id)
+				if cm.floor > 0 {
+					if cm.isRoot {
+						it.SourceURL = fmt.Sprintf("/post/%d#comment-%d", cm.postID, cm.floor)
+					} else {
+						it.SourceURL = fmt.Sprintf("/post/%d#comment-%d-r%d", cm.postID, cm.floor, cm.id)
+					}
+				} else {
+					it.SourceURL = fmt.Sprintf("/post/%d", cm.postID)
+				}
 				title := commentPostTitle[cm.postID]
 				if title != "" {
 					it.SourceLabel = "帖子《" + truncate(title, 40) + "》下的评论"
--- a/backend/service/media_library_test.go
+++ b/backend/service/media_library_test.go
@@ -25,7 +25,7 @@ func newMediaLibraryService(t *testing.T) (*UploadService, string) {
 	if err != nil {
 		t.Fatalf("open sqlite: %v", err)
 	}
-	if err := db.AutoMigrate(&model.Attachment{}, &model.User{}, &model.Post{}, &model.Comment{}); err != nil {
+	if err := db.AutoMigrate(&model.Attachment{}, &model.Blob{}, &model.User{}, &model.Post{}, &model.Comment{}); err != nil {
 		t.Fatalf("migrate: %v", err)
 	}
 	dir := t.TempDir()
@@ -250,8 +250,7 @@ func TestAdminMediaLibraryAttachSources(t *testing.T) {
 	if !ok {
 		t.Fatal("comment image missing")
 	}
-	if cimg.SourceURL != fmt.Sprintf("/post/%d#comment-", post.ID) &&
-		!strings.HasPrefix(cimg.SourceURL, fmt.Sprintf("/post/%d#comment-", post.ID)) {
+	if cimg.SourceURL != fmt.Sprintf("/post/%d#comment-1", post.ID) {
 		t.Fatalf("comment source url wrong: %+v", cimg)
 	}
 	if !strings.Contains(cimg.SourceLabel, "下的评论") {
@@ -259,6 +258,139 @@ func TestAdminMediaLibraryAttachSources(t *testing.T) {
 	}
 }

+func TestAdminMediaLibraryBookCategory(t *testing.T) {
+	s, dir := newMediaLibraryService(t)
+
+	// 书籍封面（本地磁盘）与正文插图（远程对象），另有一张普通帖子插图
+	writeMediaFile(t, dir, "images/cover.webp", []byte("fake-webp-bytes"))
+
+	if err := s.db.Create(&model.User{Username: "alice", Nickname: "爱丽丝"}).Error; err != nil {
+		t.Fatalf("create user: %v", err)
+	}
+	var alice model.User
+	if err := s.db.Where("username = ?", "alice").First(&alice).Error; err != nil {
+		t.Fatalf("load user: %v", err)
+	}
+	created := time.Date(2026, 9, 1, 10, 0, 0, 0, time.UTC)
+	mkAtt := func(source, url string) {
+		if err := s.db.Create(&model.Attachment{
+			UserID: alice.ID, Kind: model.AttachmentKindImage, Source: source,
+			URL: url, MIME: "image/webp", Size: 100, Width: 10, Height: 10,
+			CreatedAt: created,
+		}).Error; err != nil {
+			t.Fatalf("create attachment %s: %v", source, err)
+		}
+	}
+	mkAtt(model.AttachmentSourceLibraryCover, "/uploads/images/cover.webp")
+	mkAtt(model.AttachmentSourceLibraryContent, "/api/media/book-content")
+	mkAtt(model.AttachmentSourcePost, "/api/media/post-image")
+
+	items, counts, err := s.AdminMediaLibrary()
+	if err != nil {
+		t.Fatalf("AdminMediaLibrary: %v", err)
+	}
+	byURL := map[string]MediaLibraryItem{}
+	for _, it := range items {
+		byURL[it.URL] = it
+	}
+
+	// 封面（磁盘）与正文插图（远程）都归“书籍”
+	for _, u := range []string{"/uploads/images/cover.webp", "/api/media/book-content"} {
+		it, ok := byURL[u]
+		if !ok {
+			t.Fatalf("%s missing", u)
+		}
+		if it.Category != "book" || it.CategoryName != "书籍" {
+			t.Fatalf("%s should be book category, got %q/%q", u, it.Category, it.CategoryName)
+		}
+	}
+
+	// 普通帖子插图仍归 image
+	if post := byURL["/api/media/post-image"]; post.Category != "image" {
+		t.Fatalf("post image should stay image category, got %q", post.Category)
+	}
+
+	if counts["book"] != 2 || counts["image"] != 1 {
+		t.Fatalf("counts wrong: %v", counts)
+	}
+}
+
+func TestAdminMediaLibraryDedupAggregation(t *testing.T) {
+	s, dir := newMediaLibraryService(t)
+
+	writeMediaFile(t, dir, "images/dup.webp", []byte("fake-webp-bytes"))
+
+	mkUser := func(username, nickname string) model.User {
+		if err := s.db.Create(&model.User{Username: username, Nickname: nickname}).Error; err != nil {
+			t.Fatalf("create user: %v", err)
+		}
+		var u model.User
+		if err := s.db.Where("username = ?", username).First(&u).Error; err != nil {
+			t.Fatalf("load user: %v", err)
+		}
+		return u
+	}
+	alice := mkUser("alice", "爱丽丝")
+	bob := mkUser("bob", "阿Bob")
+
+	early := time.Date(2026, 9, 1, 10, 0, 0, 0, time.UTC)
+	late := early.Add(2 * time.Hour)
+
+	// 同一张图被两人先后上传（内容寻址去重后共享同一文件/对象）
+	mkAtt := func(u model.User, url string, at time.Time) {
+		if err := s.db.Create(&model.Attachment{
+			UserID: u.ID, Kind: model.AttachmentKindImage,
+			URL: url, MIME: "image/webp",
+			Size: 100, Width: 10, Height: 10, CreatedAt: at,
+		}).Error; err != nil {
+			t.Fatalf("create attachment %s: %v", url, err)
+		}
+	}
+	mkAtt(alice, "/uploads/images/dup.webp", early)
+	mkAtt(bob, "/uploads/images/dup.webp", late)
+	mkAtt(bob, "/api/media/rdup", early)
+	mkAtt(alice, "/api/media/rdup", late)
+
+	items, _, err := s.AdminMediaLibrary()
+	if err != nil {
+		t.Fatalf("AdminMediaLibrary: %v", err)
+	}
+
+	countByURL := map[string]int{}
+	byURL := map[string]MediaLibraryItem{}
+	for _, it := range items {
+		countByURL[it.URL]++
+		byURL[it.URL] = it
+	}
+
+	// 本地去重文件：单个条目，上传者/时间取最早上传的爱丽丝，引用计数 2
+	local, ok := byURL["/uploads/images/dup.webp"]
+	if !ok {
+		t.Fatal("dedup local file missing")
+	}
+	if countByURL["/uploads/images/dup.webp"] != 1 {
+		t.Fatal("dedup local file should appear exactly once")
+	}
+	if local.Uploader != "爱丽丝" || local.RefCount != 2 {
+		t.Fatalf("local dedup meta wrong: %+v", local)
+	}
+	if local.UploadedAt == nil || !local.UploadedAt.Equal(early) {
+		t.Fatalf("local dedup time should be earliest upload, got %v", local.UploadedAt)
+	}
+
+	// 远程对象同 URL 两条记录：也只出一个条目，取最早的 bob
+	remote, ok := byURL["/api/media/rdup"]
+	if !ok {
+		t.Fatal("dedup remote object missing")
+	}
+	if countByURL["/api/media/rdup"] != 1 {
+		t.Fatal("dedup remote object should appear exactly once")
+	}
+	if remote.Uploader != "阿Bob" || remote.RefCount != 2 {
+		t.Fatalf("remote dedup meta wrong: %+v", remote)
+	}
+}
+
 func TestMediaThumb(t *testing.T) {
 	s, dir := newMediaLibraryService(t)

--- a/backend/service/media_thumbs.go
+++ b/backend/service/media_thumbs.go
@@ -1,27 +1,19 @@
 package service

 import (
-	"bytes"
 	"crypto/sha1"
 	"encoding/hex"
 	"errors"
-	"image"
-	_ "image/gif"
-	_ "image/jpeg"
-	_ "image/png"
 	"os"
 	"path/filepath"
 	"strings"
-
-	webpenc "github.com/gen2brain/webp"
-	"golang.org/x/image/draw"
-	xwebp "golang.org/x/image/webp"
 )

 // 媒体库缩略图：管理后台网格不再直连原图（全量图片一次加载网络压力大）。
 // 服务端按需生成最长边 480px 的 WebP 缩略图，落盘 .thumbs/（按 URL 哈希命名）缓存，
 // 源文件更新后（mtime 更新）自动重建。仅覆盖本地 /uploads/ 图片；
 // 远程存储对象与解码失败（如动图 WebP）由调用方回退原图。
+// 解码/缩放/编码/原子落盘共用 image_variants.go 的图片处理核心。

 // MediaThumbMaxSide 缩略图最长边（网格单元 ~200px，2x DPR 足够）
 const MediaThumbMaxSide = 480
@@ -70,12 +62,7 @@ func (s *UploadService) MediaThumb(url string) ([]byte, error) {
 	if err != nil {
 		return nil, err
 	}
-	var img image.Image
-	if ext == ".webp" {
-		img, err = xwebp.Decode(bytes.NewReader(data))
-	} else {
-		img, _, err = image.Decode(bytes.NewReader(data))
-	}
+	img, err := decodeImageBytes(data, ext == ".webp")
 	if err != nil {
 		return nil, err // 如动图 WebP，调用方回退原图
 	}
@@ -94,21 +81,13 @@ func (s *UploadService) MediaThumb(url string) ([]byte, error) {
 		nh = MediaThumbMaxSide
 		nw = max(1, w*MediaThumbMaxSide/h)
 	}
-	dst := image.NewRGBA(image.Rect(0, 0, nw, nh))
-	draw.CatmullRom.Scale(dst, dst.Bounds(), img, b, draw.Src, nil)
+	dst := scaleImage(img, nw, nh)

-	var buf bytes.Buffer
-	if err := webpenc.Encode(&buf, dst, webpenc.Options{Quality: 78}); err != nil {
+	out, err := encodeLossyWebP(dst, VariantWebPQuality)
+	if err != nil {
 		return nil, err
 	}
 	// 原子落缓存（失败仅影响下次重复生成，不阻断响应）
-	if err := os.MkdirAll(filepath.Dir(thumbPath), 0o755); err == nil {
-		tmp := thumbPath + ".partial"
-		if err := os.WriteFile(tmp, buf.Bytes(), 0o644); err == nil {
-			if err := os.Rename(tmp, thumbPath); err != nil {
-				_ = os.Remove(tmp)
-			}
-		}
-	}
-	return buf.Bytes(), nil
+	_ = atomicWriteFile(thumbPath, out)
+	return out, nil
 }
--- a/backend/service/operations_mail.go
+++ b/backend/service/operations_mail.go
@@ -24,6 +24,9 @@ import (

 type mailPayload struct{ To, Subject, Body string }

+// ErrEmailRegistered 注册发码时邮箱已被占用，handler 据此返回 400 业务提示
+var ErrEmailRegistered = errors.New("该邮箱已被注册，请直接登录")
+
 func (o *Operations) smtp(ctx context.Context, c MailConfig, p *mailPayload, id string) error {
 	password, e := o.open(c.Password, "mail:password")
 	if e != nil {
@@ -392,6 +395,16 @@ func (o *Operations) SendCode(email, purpose, ip string) (int, error) {
 			return 0, nil
 		}
 	}
+	if purpose == "register" {
+		// 入口拦截：邮箱已被占用则不发码，省一次邮件资源，也给用户明确提示
+		var n int64
+		if e = o.db.Model(&model.User{}).Where("LOWER(email) = ?", email).Count(&n).Error; e != nil {
+			return 0, e
+		}
+		if n > 0 {
+			return 0, ErrEmailRegistered
+		}
+	}
 	code := randomCode()
 	hash := counterKey(email + ":" + purpose + ":" + code)
 	e = o.db.Transaction(func(tx *gorm.DB) error {
@@ -402,6 +415,7 @@ func (o *Operations) SendCode(email, purpose, ip string) (int, error) {
 	})
 	return 0, e
 }
+
 const (
 	codeVerifyMaxAttempts = 5
 	codeVerifyWindow      = 15 * 60 // 秒，与验证码有效期一致
--- a/backend/service/operations_storage.go
+++ b/backend/service/operations_storage.go
@@ -16,6 +16,8 @@ import (
 	"path/filepath"
 	"strings"
 	"time"
+
+	"gorm.io/gorm"
 )

 func (o *Operations) s3(c StorageConfig) (*minio.Client, error) {
@@ -137,6 +139,65 @@ func (o *Operations) StoreFile(path, mimeType string, public bool) (string, erro
 	}
 	return id, nil
 }
+
+// blobObjectID 内容寻址对象的稳定 ID：公开/私有加不同前缀，同字节也不共享可见性。
+func blobObjectID(hash string, public bool) string {
+	if public {
+		return "pub_" + hash
+	}
+	return "prv_" + hash
+}
+
+// StoreFileHashed 按内容 hash 幂等上传：同一 (hash, public) 只存一份，重复上传跳过传输。
+// 本地后端返回空 ID（文件留在本地 blob 目录，由调用方做引用计数）。
+func (o *Operations) StoreFileHashed(path, mimeType string, public bool, hash string) (string, error) {
+	v, version, e := o.read(o.db, "storage")
+	if e != nil {
+		return "", errors.New("读取存储配置失败")
+	}
+	c := *v.(*StorageConfig)
+	if c.Backend == "local" {
+		return "", nil
+	}
+	id := blobObjectID(hash, public)
+	// hash 相同字节必然相同：对象已存在时直接复用，省掉整次上传
+	var existing model.StoredObject
+	if e := o.db.First(&existing, "id = ?", id).Error; e == nil {
+		return id, nil
+	} else if !errors.Is(e, gorm.ErrRecordNotFound) {
+		return "", e
+	}
+	client, e := o.s3(c)
+	if e != nil {
+		return "", e
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), 60*time.Second)
+	defer cancel()
+	f, e := os.Open(path)
+	if e != nil {
+		return "", e
+	}
+	stat, e := f.Stat()
+	if e != nil {
+		_ = f.Close()
+		return "", e
+	}
+	key := c.Prefix + "objects/" + id
+	if _, e = client.PutObject(ctx, c.Bucket, key, f, stat.Size(), minio.PutObjectOptions{ContentType: mimeType, DisableMultipart: true}); e != nil {
+		_ = f.Close()
+		return "", errors.New("上传到 S3 失败，当前目标未自动切换")
+	}
+	_ = f.Close()
+	obj := model.StoredObject{ID: id, ConfigName: fmt.Sprintf("storage-%d", version), Key: key, MIME: mimeType, Public: public}
+	if e = o.db.Create(&obj).Error; e != nil {
+		if isUniqueConflict(e) { // 并发：另一请求已写入同内容对象，直接复用
+			return id, nil
+		}
+		_ = client.RemoveObject(ctx, c.Bucket, key, minio.RemoveObjectOptions{})
+		return "", errors.New("保存文件记录失败")
+	}
+	return id, nil
+}
 func (o *Operations) OpenObject(ctx context.Context, id string, requirePublic bool) (io.ReadCloser, string, error) {
 	var obj model.StoredObject
 	if e := o.db.First(&obj, "id = ?", id).Error; e != nil {
--- a/backend/service/overview.go
+++ b/backend/service/overview.go
@@ -72,18 +72,18 @@ type NewUserItem struct {

 // OverviewData 首页聚合数据
 type OverviewData struct {
-	Stats              OverviewStats      `json:"stats"`
-	Hot                []PostListItem     `json:"hot"`
-	ActiveUsers        []ActiveUser       `json:"active_users"`
-	Boards             []BoardCount       `json:"boards"`
-	Announcements      []AnnouncementItem `json:"announcements"`
-	AnnouncementsTotal int64              `json:"announcements_total"`
-	SidebarPages       []SidebarPageItem  `json:"sidebar_pages"`
-	NewUsers           []NewUserItem      `json:"new_users"`
-	Checkin            *CheckinStatus     `json:"checkin,omitempty"`
-	Ads                []PublicAdItem     `json:"ads"`
-	AdsPanelTitle      string             `json:"ads_panel_title"`
-	AdsEnabled         bool               `json:"ads_enabled"`
+	Stats              OverviewStats       `json:"stats"`
+	Hot                []PostListItem      `json:"hot"`
+	ActiveUsers        []ActiveUser        `json:"active_users"`
+	Boards             []BoardCount        `json:"boards"`
+	Announcements      []AnnouncementItem  `json:"announcements"`
+	AnnouncementsTotal int64               `json:"announcements_total"`
+	SidebarPages       []SidebarPageItem   `json:"sidebar_pages"`
+	NewUsers           []NewUserItem       `json:"new_users"`
+	Checkin            *CheckinStatus      `json:"checkin,omitempty"`
+	Ads                []PublicAdItem      `json:"ads"`
+	AdsPanelTitle      string              `json:"ads_panel_title"`
+	AdsEnabled         bool                `json:"ads_enabled"`
 	Sponsors           []PublicSponsorItem `json:"sponsors"`
 	SponsorsPanelTitle string              `json:"sponsors_panel_title"`
 	SponsorsEnabled    bool                `json:"sponsors_enabled"`
--- a/backend/service/post.go
+++ b/backend/service/post.go
@@ -457,37 +457,37 @@ type PostAttachmentDTO struct {

 // PostDetail 帖子详情（含可见性裁剪与附件）
 type PostDetail struct {
-	ID            uint                `json:"id"`
-	BoardID       uint                `json:"board_id"`
-	UserID        uint                `json:"user_id"`
-	Title         string              `json:"title"`
-	Content       string              `json:"content"`
-	Tags          string              `json:"tags"`
-	PostType      string              `json:"post_type"`
-	ContentAccess string              `json:"content_access"`
-	AccessPoints  int                 `json:"access_points"`
-	TypeMeta      string              `json:"type_meta"`
-	TypeStatus    string              `json:"type_status,omitempty"`
-	Pinned        int                 `json:"pinned"`
-	Recommended   bool                `json:"recommended"`
-	Locked        bool                `json:"locked"` // 管理员手动锁定：普通用户不可编辑/回复（staff 豁免）
-	Status        string              `json:"status"`
-	LikeCount     int                 `json:"like_count"`
-	ViewCount     int                 `json:"view_count"`
-	CommentCount  int                 `json:"comment_count"`
-	Liked         bool                `json:"liked"`
-	Favorited     bool                `json:"favorited"` // 当前查看者是否已收藏（详情接口实时填充）
-	Edited        bool                `json:"edited"`    // 是否存在编辑历史快照（决定"更新于/编辑历史"入口展示）
+	ID            uint   `json:"id"`
+	BoardID       uint   `json:"board_id"`
+	UserID        uint   `json:"user_id"`
+	Title         string `json:"title"`
+	Content       string `json:"content"`
+	Tags          string `json:"tags"`
+	PostType      string `json:"post_type"`
+	ContentAccess string `json:"content_access"`
+	AccessPoints  int    `json:"access_points"`
+	TypeMeta      string `json:"type_meta"`
+	TypeStatus    string `json:"type_status,omitempty"`
+	Pinned        int    `json:"pinned"`
+	Recommended   bool   `json:"recommended"`
+	Locked        bool   `json:"locked"` // 管理员手动锁定：普通用户不可编辑/回复（staff 豁免）
+	Status        string `json:"status"`
+	LikeCount     int    `json:"like_count"`
+	ViewCount     int    `json:"view_count"`
+	CommentCount  int    `json:"comment_count"`
+	Liked         bool   `json:"liked"`
+	Favorited     bool   `json:"favorited"` // 当前查看者是否已收藏（详情接口实时填充）
+	Edited        bool   `json:"edited"`    // 是否存在编辑历史快照（决定"更新于/编辑历史"入口展示）
 	// 最后一条已发布评论时间；null=无回复（旧帖判定回落 created_at）
 	LastReplyAt *time.Time `json:"last_reply_at,omitempty"`
 	// 旧帖回复确认提示：按查看者实时计算，命中才返回；前端存在即弹确认框
-	NecroReply    *NecroReplyHint `json:"necro_reply,omitempty"`
-	CreatedAt     time.Time       `json:"created_at"`
-	UpdatedAt     time.Time       `json:"updated_at"`
-	Board         model.Board     `json:"board"`
-	User          model.User      `json:"user"`
-	ContentLocked bool            `json:"content_locked"`
-	AccessHint    string          `json:"access_hint,omitempty"`
+	NecroReply    *NecroReplyHint     `json:"necro_reply,omitempty"`
+	CreatedAt     time.Time           `json:"created_at"`
+	UpdatedAt     time.Time           `json:"updated_at"`
+	Board         model.Board         `json:"board"`
+	User          model.User          `json:"user"`
+	ContentLocked bool                `json:"content_locked"`
+	AccessHint    string              `json:"access_hint,omitempty"`
 	Attachments   []PostAttachmentDTO `json:"attachments"`
 	Question      *QuestionState      `json:"question,omitempty"`
 	Poll          *PollState          `json:"poll,omitempty"`
@@ -620,7 +620,7 @@ func buildPostDetail(post *model.Post) *PostDetail {
 		ContentAccess: model.NormalizeContentAccess(post.ContentAccess),
 		AccessPoints:  post.AccessPoints, TypeMeta: post.TypeMeta,
 		TypeStatus: ComputeTypeStatus(post.PostType, post.TypeMeta),
-		Pinned: post.Pinned, Recommended: post.Recommended, Locked: post.Locked, Status: post.Status,
+		Pinned:     post.Pinned, Recommended: post.Recommended, Locked: post.Locked, Status: post.Status,
 		LikeCount: post.LikeCount, ViewCount: post.ViewCount, CommentCount: post.CommentCount,
 		Liked: post.Liked, CreatedAt: post.CreatedAt, UpdatedAt: post.UpdatedAt,
 		Board: post.Board, User: post.User,
--- a/backend/service/post_file.go
+++ b/backend/service/post_file.go
@@ -2,10 +2,12 @@ package service

 import (
 	"crypto/rand"
+	"crypto/sha256"
 	"encoding/hex"
 	"errors"
 	"fmt"
 	"io"
+	"log"
 	"os"
 	"path/filepath"
 	"unicode/utf8"
@@ -145,8 +147,9 @@ func (s *PostFileService) SaveDraftFile(userID uint, originalName string, src io
 	if err != nil {
 		return nil, err
 	}
-	// LimitReader 多读 1 字节以区分「刚好上限」与「超限」
-	written, copyErr := io.Copy(f, io.LimitReader(src, maxB+1))
+	// LimitReader 多读 1 字节以区分「刚好上限」与「超限」；落盘同时计算内容 hash
+	hasher := sha256.New()
+	written, copyErr := io.Copy(io.MultiWriter(f, hasher), io.LimitReader(src, maxB+1))
 	_ = f.Close()
 	if copyErr != nil {
 		_ = os.Remove(tmp)
@@ -167,28 +170,45 @@ func (s *PostFileService) SaveDraftFile(userID uint, originalName string, src io
 		return nil, err
 	}

-	att := &model.PostAttachment{
-		PostID:      0,
-		UserID:      userID,
-		Name:        name,
-		StoredName:  stored,
-		MIME:        mimeType,
-		Size:        int(written),
-		PricePoints: pricePoints,
-	}
+	// 内容寻址：私有 blob 以 hash 命名（不带扩展名，下载时以 att.MIME + 原文件名下发）
+	hash := hex.EncodeToString(hasher.Sum(nil))
+	final := absPath(s.dir, hash)
+	var objectID string
 	if s.ops != nil {
-		id, e := s.ops.StoreFile(full, att.MIME, false)
+		id, e := s.ops.StoreFileHashed(full, mimeType, false, hash)
 		if e != nil {
 			_ = os.Remove(full)
 			return nil, e
 		}
-		att.ObjectID = id
+		objectID = id
 		if id != "" {
 			_ = os.Remove(full)
 		}
 	}
-	if err := s.db.Create(att).Error; err != nil {
-		_ = os.Remove(full)
+	if objectID == "" {
+		if e := placeLocalBlob(full, final); e != nil {
+			return nil, e
+		}
+	}
+
+	att := &model.PostAttachment{
+		PostID:      0,
+		UserID:      userID,
+		Name:        name,
+		StoredName:  hash,
+		BlobHash:    hash,
+		ObjectID:    objectID,
+		MIME:        mimeType,
+		Size:        int(written),
+		PricePoints: pricePoints,
+	}
+	if err := s.db.Transaction(func(tx *gorm.DB) error {
+		if e := acquireBlobRef(tx, hash, false, int(written), mimeType, objectID); e != nil {
+			return e
+		}
+		return tx.Create(att).Error
+	}); err != nil {
+		s.releasePostBlobBestEffort(hash)
 		return nil, err
 	}
 	return att, nil
@@ -283,14 +303,51 @@ func (s *PostFileService) DeleteOwn(userID, attID uint) error {
 	if att.UserID != userID {
 		return ErrAttachmentForbidden
 	}
-	path := absPath(s.dir, att.StoredName)
 	if err := s.db.Delete(&att).Error; err != nil {
 		return err
 	}
+	if att.BlobHash != "" {
+		return s.releasePostBlob(&att)
+	}
 	if s.ops != nil && att.ObjectID != "" {
 		return s.ops.RemoveObject(att.ObjectID)
 	}
-	_ = os.Remove(path)
+	_ = os.Remove(absPath(s.dir, att.StoredName))
+	return nil
+}
+
+// releasePostBlob 私有附件 blob 引用计数-1；最后一个引用删除时回收物理文件
+func (s *PostFileService) releasePostBlob(att *model.PostAttachment) error {
+	b, last, err := releaseBlobRef(s.db, att.BlobHash, false)
+	if err != nil || !last {
+		return err
+	}
+	return s.removePrivateBlobObject(b)
+}
+
+// releasePostBlobBestEffort 附件记录落库失败时回滚刚加的引用，错误只记日志
+func (s *PostFileService) releasePostBlobBestEffort(hash string) {
+	b, last, err := releaseBlobRef(s.db, hash, false)
+	if err != nil {
+		log.Printf("[post-file] 回滚 blob 引用失败 hash=%s: %v", hash, err)
+		return
+	}
+	if !last {
+		return
+	}
+	if err := s.removePrivateBlobObject(b); err != nil {
+		log.Printf("[post-file] 回滚 blob 物理文件失败 hash=%s: %v", hash, err)
+	}
+}
+
+// removePrivateBlobObject 引用归零后的物理回收（私有 blob 文件名即 hash，无扩展名）
+func (s *PostFileService) removePrivateBlobObject(b model.Blob) error {
+	if b.ObjectID != "" && s.ops != nil {
+		return s.ops.RemoveObject(b.ObjectID)
+	}
+	if err := os.Remove(absPath(s.dir, b.Hash)); err != nil && !os.IsNotExist(err) {
+		log.Printf("[post-file] 删除 blob 文件失败 hash=%s: %v", b.Hash, err)
+	}
 	return nil
 }

--- a/backend/service/post_interact.go
+++ b/backend/service/post_interact.go
@@ -472,6 +472,7 @@ func EnsureDeadlineOnPublish(typeMeta, postType string, publishedAt time.Time) (
 type AcceptedAnswer struct {
 	ID        uint               `json:"id"`
 	Floor     int                `json:"floor"`
+	IsRoot    bool               `json:"is_root"` // false = 楼中楼回复，锚点需 #comment-{floor}-r{id}
 	Content   string             `json:"content"`
 	CreatedAt time.Time          `json:"created_at"`
 	Deleted   bool               `json:"deleted,omitempty"`
@@ -736,6 +737,7 @@ func (s *PostService) loadAcceptedAnswer(postID, commentID uint, floor int, view
 	ans := &AcceptedAnswer{
 		ID:        c.ID,
 		Floor:     floor,
+		IsRoot:    c.ParentID == nil,
 		CreatedAt: c.CreatedAt,
 	}
 	staff := c.DeletedAt.Valid && c.DeletedBy != 0 && c.DeletedBy != c.UserID
--- a/backend/service/ratelimit.go
+++ b/backend/service/ratelimit.go
@@ -85,6 +85,7 @@ const (
 	RateAdSubmit     = "ad_submit"     // 广告申购 5/分钟（按 IP）
 	RateCaptcha      = "captcha"       // 验证码刷新 30/分钟
 	RateTelemetry    = "telemetry"     // 页面浏览埋点 120/分钟（按 IP）
+	RateSnippet      = "snippet"       // 代码片段创建/Fork 10/分钟
 )

 // DefaultRateLimiter 创建默认速率限制器
@@ -102,5 +103,6 @@ func DefaultRateLimiter() *RateLimiter {
 	rl.SetLimit(RateAdSubmit, 5)      // 广告申购 5/分钟
 	rl.SetLimit(RateCaptcha, 30)      // 验证码 30/分钟
 	rl.SetLimit(RateTelemetry, 120)   // 埋点 120/分钟
+	rl.SetLimit(RateSnippet, 10)      // 代码片段 10/分钟
 	return rl
 }
--- a/backend/service/setting.go
+++ b/backend/service/setting.go
@@ -202,6 +202,7 @@ type PublicSiteSettings struct {
 	BrandMark            string       `json:"brand_mark"`
 	BrandLogoSize        string       `json:"brand_logo_size"`
 	BrandLogoFit         string       `json:"brand_logo_fit"`
+	BrandSloganVisible   bool         `json:"brand_slogan_visible"`
 	FooterLinks          []FooterLink `json:"footer_links"`

 	// 积分增长规则（经济规则公开透明，签到卡等可直出）
--- a/backend/service/site_page.go
+++ b/backend/service/site_page.go
@@ -12,7 +12,7 @@ import (
 )

 var (
-	sitePageSlugRe       = regexp.MustCompile(`^[a-z0-9]+(?:-[a-z0-9]+)*$`)
+	sitePageSlugRe        = regexp.MustCompile(`^[a-z0-9]+(?:-[a-z0-9]+)*$`)
 	ErrSitePageNotDeleted = errors.New("仅已删除的单页可彻底删除")
 )

--- a/backend/service/snippet.go
+++ b/backend/service/snippet.go
--- a/backend/service/timeline_release.go
+++ b/backend/service/timeline_release.go
@@ -90,7 +90,7 @@ func (s *SettingService) ImportTimelineFromReleases(urls []string) (*TimelineGit
 	client := &http.Client{
 		Timeout: timelineGitHTTPTimeout,
 		Transport: &http.Transport{
-			DialContext:          publicOnlyDial,
+			DialContext:         publicOnlyDial,
 			TLSHandshakeTimeout: timelineGitHTTPTimeout,
 			ForceAttemptHTTP2:   true,
 		},
--- a/backend/service/upload.go
+++ b/backend/service/upload.go
@@ -113,46 +113,57 @@ func (s *UploadService) SaveAvatar(userID uint, data []byte) (*model.Attachment,
 		return nil, errors.New("头像尺寸需在 64~512px 之间")
 	}

-	nameBytes := make([]byte, 16)
-	if _, err := rand.Read(nameBytes); err != nil {
-		return nil, err
-	}
-	filename := hex.EncodeToString(nameBytes) + ".webp"
+	hash := sha256Hex(data)
+	filename := hash + ".webp"
 	fullPath := filepath.Join(s.dir, "avatars", filename)
-	if err := os.WriteFile(fullPath, data, 0o644); err != nil {
-		return nil, err
+	url := "/uploads/avatars/" + filename
+	var objectID string
+	writeLocal := func() error {
+		if _, err := os.Stat(fullPath); err == nil {
+			return nil // 同内容头像已落盘，字节必然一致，无需重写
+		}
+		return os.WriteFile(fullPath, data, 0o644)
 	}
-
-	att := &model.Attachment{
-		UserID: userID,
-		Kind:   model.AttachmentKindAvatar,
-		URL:    "/uploads/avatars/" + filename,
-		MIME:   "image/webp",
-		Size:   len(data),
-		Width:  cfg.Width,
-		Height: cfg.Height,
-	}
-
 	if s.ops != nil {
-		id, e := s.ops.StoreFile(fullPath, att.MIME, true)
+		if err := writeLocal(); err != nil {
+			return nil, err
+		}
+		id, e := s.ops.StoreFileHashed(fullPath, "image/webp", true, hash)
 		if e != nil {
 			_ = os.Remove(fullPath)
 			return nil, e
 		}
+		objectID = id
 		if id != "" {
-			att.URL = "/api/media/" + id
+			url = "/api/media/" + id
 			_ = os.Remove(fullPath)
 		}
+	} else if err := writeLocal(); err != nil {
+		return nil, err
 	}
-	// 附件记录与用户头像更新在同一事务内完成
+
+	att := &model.Attachment{
+		UserID:   userID,
+		Kind:     model.AttachmentKindAvatar,
+		URL:      url,
+		BlobHash: hash,
+		MIME:     "image/webp",
+		Size:     len(data),
+		Width:    cfg.Width,
+		Height:   cfg.Height,
+	}
+	// 附件记录、blob 引用与用户头像更新在同一事务内完成
 	err = s.db.Transaction(func(tx *gorm.DB) error {
+		if err := acquireBlobRef(tx, hash, true, len(data), "image/webp", objectID); err != nil {
+			return err
+		}
 		if err := tx.Create(att).Error; err != nil {
 			return err
 		}
 		return tx.Model(&model.User{}).Where("id = ?", userID).Update("avatar", att.URL).Error
 	})
 	if err != nil {
-		_ = os.Remove(fullPath) // DB 失败时清理已落盘文件
+		s.releaseBlobBestEffort(hash, true, "/uploads/avatars/"+filename)
 		return nil, err
 	}
 	return att, nil
@@ -238,7 +249,7 @@ func (s *UploadService) transcodeImageToWebP(tmp, name, ext string) (string, str
 }

 // SaveImage 流式保存帖子插图：校验格式/大小/尺寸 → JPEG/PNG 转 WebP → 落盘 → 写 attachments（kind=image）
-func (s *UploadService) SaveImage(userID uint, src io.Reader) (*model.Attachment, error) {
+func (s *UploadService) SaveImage(userID uint, src io.Reader, source string) (*model.Attachment, error) {
 	if src == nil {
 		return nil, errors.New("文件为空")
 	}
@@ -351,28 +362,51 @@ func (s *UploadService) SaveImage(userID uint, src io.Reader) (*model.Attachment
 		}
 	}

-	att := &model.Attachment{
-		UserID: userID,
-		Kind:   model.AttachmentKindImage,
-		URL:    "/uploads/images/" + storeName,
-		MIME:   storeMime,
-		Size:   int(storeSize),
-		Width:  w,
-		Height: h,
+	// 对最终存储字节做内容寻址（JPEG/PNG 已在上面转成 WebP，同图重复上传才能命中）
+	hash, err := hashFile(storePath)
+	if err != nil {
+		_ = os.Remove(storePath)
+		return nil, err
 	}
+	finalName := hash + strings.ToLower(filepath.Ext(storeName))
+	url := "/uploads/images/" + finalName
+	var objectID string
 	if s.ops != nil {
-		id, e := s.ops.StoreFile(storePath, att.MIME, true)
+		id, e := s.ops.StoreFileHashed(storePath, storeMime, true, hash)
 		if e != nil {
 			_ = os.Remove(storePath)
 			return nil, e
 		}
+		objectID = id
 		if id != "" {
-			att.URL = "/api/media/" + id
+			// 远程后端：以对象 ID 为访问地址，本地临时副本回收
+			url = "/api/media/" + id
 			_ = os.Remove(storePath)
+		} else if e := placeLocalBlob(storePath, filepath.Join(s.dir, "images", finalName)); e != nil {
+			return nil, e
 		}
+	} else if e := placeLocalBlob(storePath, filepath.Join(s.dir, "images", finalName)); e != nil {
+		return nil, e
 	}
-	if err := s.db.Create(att).Error; err != nil {
-		_ = os.Remove(storePath)
+
+	att := &model.Attachment{
+		UserID:   userID,
+		Kind:     model.AttachmentKindImage,
+		Source:   normalizeImageSource(source),
+		URL:      url,
+		BlobHash: hash,
+		MIME:     storeMime,
+		Size:     int(storeSize),
+		Width:    w,
+		Height:   h,
+	}
+	if err := s.db.Transaction(func(tx *gorm.DB) error {
+		if err := acquireBlobRef(tx, hash, true, int(storeSize), storeMime, objectID); err != nil {
+			return err
+		}
+		return tx.Create(att).Error
+	}); err != nil {
+		s.releaseBlobBestEffort(hash, true, url)
 		return nil, err
 	}
 	return att, nil
@@ -585,9 +619,20 @@ func (s *UploadService) CopyBackgroundFromMedia(userID, attachmentID uint) (stri
 	return s.SaveBackground(f)
 }

+// normalizeImageSource 把外部传入的图片来源收敛到白名单，未知值回退为 post
+func normalizeImageSource(s string) string {
+	switch s {
+	case model.AttachmentSourceLibraryCover, model.AttachmentSourceLibraryContent:
+		return s
+	default:
+		return model.AttachmentSourcePost
+	}
+}
+
 // CopyImageFromMedia 把当前用户媒体库里的一张图复制一份新插图（落 uploads/images 并记一条本人附件）
 // 用于书籍封面等长期引用场景：与原图解耦，原图删除后副本仍可用
-func (s *UploadService) CopyImageFromMedia(userID, attachmentID uint) (*model.Attachment, error) {
+// source 决定副本的来源标记（如 library_cover）
+func (s *UploadService) CopyImageFromMedia(userID, attachmentID uint, source string) (*model.Attachment, error) {
 	var att model.Attachment
 	if err := s.db.Where("id = ? AND user_id = ?", attachmentID, userID).First(&att).Error; err != nil {
 		return nil, errors.New("图片不存在或不属于你")
@@ -600,7 +645,7 @@ func (s *UploadService) CopyImageFromMedia(userID, attachmentID uint) (*model.At
 			return nil, e
 		}
 		defer r.Close()
-		return s.SaveImage(userID, r)
+		return s.SaveImage(userID, r, source)
 	}
 	abs, ok := s.safeUploadPath(att.URL)
 	if !ok {
@@ -611,7 +656,7 @@ func (s *UploadService) CopyImageFromMedia(userID, attachmentID uint) (*model.At
 		return nil, errors.New("读取图片失败")
 	}
 	defer f.Close()
-	return s.SaveImage(userID, f)
+	return s.SaveImage(userID, f, source)
 }

 // BackgroundFileExists 确认 URL 对应文件在 backgrounds 目录内
@@ -667,6 +712,15 @@ func (s *UploadService) ListMedia(userID uint) ([]model.Attachment, error) {
 	return list, err
 }

+// FindMediaBySource 按来源查本人附件（存在返回记录，不存在返回 error）
+func (s *UploadService) FindMediaBySource(userID, attachmentID uint, source string) (*model.Attachment, error) {
+	var att model.Attachment
+	if err := s.db.Where("id = ? AND user_id = ? AND source = ?", attachmentID, userID, source).First(&att).Error; err != nil {
+		return nil, err
+	}
+	return &att, nil
+}
+
 // ErrAttachmentInUse 图片正被帖子内容引用，不可物理删除
 var ErrAttachmentInUse = errors.New("该图片已被帖子使用，无法删除")

@@ -701,6 +755,10 @@ func (s *UploadService) DeleteAttachment(userID, attachmentID uint) error {
 		return err
 	}

+	if att.BlobHash != "" {
+		return s.releaseAttachmentBlob(&att)
+	}
+
 	if s.ops != nil && strings.HasPrefix(att.URL, "/api/media/") {
 		if e := s.ops.RemoveObject(RemoteObjectID(att.URL)); e != nil {
 			return errors.New("记录已删除，远程文件清理未完成，请联系管理员")
@@ -715,4 +773,47 @@ func (s *UploadService) DeleteAttachment(userID, attachmentID uint) error {
 	return nil
 }

+// releaseAttachmentBlob 公开图片 blob 引用计数-1；最后一个引用删除时回收物理文件
+func (s *UploadService) releaseAttachmentBlob(att *model.Attachment) error {
+	b, last, err := releaseBlobRef(s.db, att.BlobHash, true)
+	if err != nil || !last {
+		return err
+	}
+	return s.removePublicBlobObject(b, att.URL)
+}
+
+// releaseBlobBestEffort 业务记录落库失败时回滚刚加的引用，错误只记日志
+func (s *UploadService) releaseBlobBestEffort(hash string, public bool, localURL string) {
+	b, last, err := releaseBlobRef(s.db, hash, public)
+	if err != nil {
+		log.Printf("[upload] 回滚 blob 引用失败 hash=%s: %v", hash, err)
+		return
+	}
+	if !last {
+		return
+	}
+	if err := s.removePublicBlobObject(b, localURL); err != nil {
+		log.Printf("[upload] 回滚 blob 物理文件失败 hash=%s: %v", hash, err)
+	}
+}
+
+// removePublicBlobObject 引用归零后的物理回收：远程对象失败需上抛（与历史行为一致），
+// 本地文件失败只记日志（下次同内容上传会自愈覆盖）。
+func (s *UploadService) removePublicBlobObject(b model.Blob, localURL string) error {
+	if b.ObjectID != "" && s.ops != nil {
+		if e := s.ops.RemoveObject(b.ObjectID); e != nil {
+			return errors.New("记录已删除，远程文件清理未完成，请联系管理员")
+		}
+		return nil
+	}
+	if localURL == "" {
+		return nil
+	}
+	abs := filepath.Join(s.dir, filepath.FromSlash(strings.TrimPrefix(localURL, "/uploads/")))
+	if err := os.Remove(abs); err != nil && !os.IsNotExist(err) {
+		log.Printf("[upload] 删除 blob 文件失败 hash=%s path=%s: %v", b.Hash, abs, err)
+	}
+	return nil
+}
+
 func (s *UploadService) WithOperations(o *Operations) { s.ops = o }
--- a/backend/service/upload_webp_test.go
+++ b/backend/service/upload_webp_test.go
@@ -25,7 +25,7 @@ func newUploadTestService(t *testing.T) (*UploadService, string) {
 	if err != nil {
 		t.Fatalf("open sqlite: %v", err)
 	}
-	if err := db.AutoMigrate(&model.Attachment{}); err != nil {
+	if err := db.AutoMigrate(&model.Attachment{}, &model.Blob{}); err != nil {
 		t.Fatalf("migrate: %v", err)
 	}
 	dir := t.TempDir()
@@ -60,7 +60,7 @@ func TestSaveImageTranscodesJPEGToWebP(t *testing.T) {
 		t.Fatalf("encode jpeg: %v", err)
 	}

-	att, err := s.SaveImage(1, bytes.NewReader(in.Bytes()))
+	att, err := s.SaveImage(1, bytes.NewReader(in.Bytes()), "post")
 	if err != nil {
 		t.Fatalf("SaveImage: %v", err)
 	}
@@ -98,7 +98,7 @@ func TestSaveImageTranscodesPNGLosslessKeepsAlpha(t *testing.T) {
 		t.Fatalf("encode png: %v", err)
 	}

-	att, err := s.SaveImage(1, bytes.NewReader(in.Bytes()))
+	att, err := s.SaveImage(1, bytes.NewReader(in.Bytes()), "post")
 	if err != nil {
 		t.Fatalf("SaveImage: %v", err)
 	}
@@ -133,7 +133,7 @@ func TestSaveImageKeepsGIFAsIs(t *testing.T) {
 		t.Fatalf("encode gif: %v", err)
 	}

-	att, err := s.SaveImage(1, bytes.NewReader(in.Bytes()))
+	att, err := s.SaveImage(1, bytes.NewReader(in.Bytes()), "post")
 	if err != nil {
 		t.Fatalf("SaveImage: %v", err)
 	}
@@ -156,7 +156,7 @@ func TestSaveImageKeepsWebPAsIs(t *testing.T) {
 		t.Fatalf("encode webp: %v", err)
 	}

-	att, err := s.SaveImage(1, bytes.NewReader(in.Bytes()))
+	att, err := s.SaveImage(1, bytes.NewReader(in.Bytes()), "post")
 	if err != nil {
 		t.Fatalf("SaveImage: %v", err)
 	}
--- a/docs/images/wechat.png
+++ b/docs/images/wechat.png
--- a/docs/images/zfb.png
+++ b/docs/images/zfb.png
--- a/docs/images/书库.png
+++ b/docs/images/书库.png
--- a/docs/images/代码片段.png
+++ b/docs/images/代码片段.png
--- a/docs/images/帖子详情.png
+++ b/docs/images/帖子详情.png
--- a/docs/images/管理后台.png
+++ b/docs/images/管理后台.png
--- a/docs/images/访问统计.png
+++ b/docs/images/访问统计.png
--- a/docs/images/首页.png
+++ b/docs/images/首页.png
--- a/frontend/app/about/page.tsx
+++ b/frontend/app/about/page.tsx
@@ -9,7 +9,7 @@ import {
 } from "@/lib/api";
 import { authCookieHeader } from "@/lib/cookies";
 import { getMeCached, getPublicSettingsCached } from "@/lib/serverData";
-import { isAdminOrAbove } from "@/lib/roles";
+import { hasPerm, PERMS } from "@/lib/roles";
 import { formatDate } from "@/lib/format";
 import { pageGlyph } from "@/lib/pageGlyph";
 import {
@@ -94,7 +94,7 @@ export default async function AboutIndexPage() {
  const announcements = overview?.announcements ?? [];
  const siteLead = settings.site_description?.trim() || undefined;
  const urlStyle = settings.url_style;
-  const canManagePages = !!me.user && isAdminOrAbove(me.user.role);
+  const canManagePages = !!me.user && hasPerm(me.user, PERMS.PAGES);

  const left = <SiteDocIdentity kind="about" lead={siteLead} />;
  const right = <SiteDocAnnoNav items={announcements} />;
--- a/frontend/app/admin/ads/AdsAdmin.tsx
+++ b/frontend/app/admin/ads/AdsAdmin.tsx
@@ -46,6 +46,7 @@ import Modal from "@/components/Modal";
 import { AdText } from "@/components/AdText";
 import { formatRelative } from "@/lib/format";
 import { toast } from "@/lib/toast";
+import { densitySrcSet, isOwnImage, pickVariantWidth, variantURL } from "@/lib/responsiveImage";

 type StatusFilter = "" | "pending" | "active" | "rejected" | "expired";
 type SectionId = "overview" | "queue" | "promote" | "sponsors";
@@ -882,8 +883,14 @@ function AdCard({
      {/* 预览缩略 */}
      <div className="j13-ads-thumb shrink-0" aria-hidden>
        {ad.kind === "image" && ad.image_url ? (
+          // 88×44 缩略位：本站图走 96/160 密度变体；外链图保持原地址
          // eslint-disable-next-line @next/next/no-img-element
-          <img src={ad.image_url} alt="" className="h-full w-full object-contain" />
+          <img
+            src={isOwnImage(ad.image_url) ? variantURL(ad.image_url, pickVariantWidth(88)) : ad.image_url}
+            srcSet={isOwnImage(ad.image_url) ? densitySrcSet(ad.image_url, 88) : undefined}
+            alt=""
+            className="h-full w-full object-contain"
+          />
        ) : ad.kind === "text" && ad.title ? (
          <div className="flex h-full w-full items-center justify-center p-1.5">
            <AdText title={ad.title} textColor={ad.text_color} bgColor={ad.bg_color} />
@@ -990,8 +997,14 @@ function PaymentEditor({
      {/* 二维码：点击即上传 */}
      <label className="j13-ads-qrbox shrink-0 cursor-pointer" title="点击上传/更换收款码">
        {payment.qr_url ? (
+          // 96×96 收款码位：本站图走 96/160 变体
          // eslint-disable-next-line @next/next/no-img-element
-          <img src={payment.qr_url} alt="" className="h-full w-full object-contain" />
+          <img
+            src={isOwnImage(payment.qr_url) ? variantURL(payment.qr_url, pickVariantWidth(96)) : payment.qr_url}
+            srcSet={isOwnImage(payment.qr_url) ? densitySrcSet(payment.qr_url, 96) : undefined}
+            alt=""
+            className="h-full w-full object-contain"
+          />
        ) : (
          <span className="flex flex-col items-center gap-1 text-[11px]" style={{ color: "var(--ink-3)" }}>
            <Upload size={16} />
@@ -1084,8 +1097,14 @@ function SponsorEditor({
      {/* Logo：点击即上传 */}
      <label className="j13-ads-logo shrink-0 cursor-pointer" title="点击上传/更换 Logo">
        {item.logo_url ? (
+          // 120×56 Logo 位：本站图走 160/256 变体
          // eslint-disable-next-line @next/next/no-img-element
-          <img src={item.logo_url} alt="" className="h-full w-full rounded-lg object-contain" />
+          <img
+            src={isOwnImage(item.logo_url) ? variantURL(item.logo_url, pickVariantWidth(120)) : item.logo_url}
+            srcSet={isOwnImage(item.logo_url) ? densitySrcSet(item.logo_url, 120) : undefined}
+            alt=""
+            className="h-full w-full rounded-lg object-contain"
+          />
        ) : (
          <span className="flex flex-col items-center gap-1 text-[11px]" style={{ color: "var(--ink-3)" }}>
            <Upload size={15} />
--- a/frontend/app/admin/ads/page.tsx
+++ b/frontend/app/admin/ads/page.tsx
@@ -12,7 +12,7 @@ import {
  type SponsorsConfig,
 } from "@/lib/api";
 import { getMeCached } from "@/lib/serverData";
-import { isAdminOrAbove } from "@/lib/roles";
+import { hasPerm, PERMS } from "@/lib/roles";
 import Forbidden from "../Forbidden";

 export const metadata: Metadata = {
@@ -22,7 +22,7 @@ export const metadata: Metadata = {
 export default async function AdminAdsPage() {
  const cookie = authCookieHeader(await cookies());
  const me = await getMeCached(cookie || undefined);
-  if (!me.user || !isAdminOrAbove(me.user.role)) {
+  if (!me.user || !hasPerm(me.user, PERMS.ADS)) {
    return <Forbidden text="推广与赞助管理仅管理员及以上角色可操作。" />;
  }

--- a/frontend/app/admin/analytics/details/page.tsx
+++ b/frontend/app/admin/analytics/details/page.tsx
@@ -138,7 +138,7 @@ function DetailsInner() {
            <div className="w-full sm:w-56">
              <AdminSearchField
                value={path}
-                onChange={(v) => { setPath(v); }}
+                onChange={(v) => { setPath(v); resetPage(); }}
                onSubmit={resetPage}
                onClear={() => { setPath(""); resetPage(); }}
                placeholder="路径模糊匹配，回车应用"
@@ -148,7 +148,7 @@ function DetailsInner() {
            <div className="w-full sm:w-48">
              <AdminSearchField
                value={ip}
-                onChange={setIp}
+                onChange={(v) => { setIp(v); resetPage(); }}
                onSubmit={resetPage}
                onClear={() => { setIp(""); resetPage(); }}
                placeholder="按 IP 精确筛选"
@@ -158,7 +158,7 @@ function DetailsInner() {
            <div className="w-full sm:w-44">
              <AdminSearchField
                value={bot}
-                onChange={setBot}
+                onChange={(v) => { setBot(v); resetPage(); }}
                onSubmit={resetPage}
                onClear={() => { setBot(""); resetPage(); }}
                placeholder="按爬虫名精确筛选"
--- a/frontend/app/admin/announcements/[id]/edit/page.tsx
+++ b/frontend/app/admin/announcements/[id]/edit/page.tsx
@@ -3,7 +3,7 @@ import { Suspense } from "react";
 import { cookies } from "next/headers";
 import { authCookieHeader } from "@/lib/cookies";
 import { getMeCached } from "@/lib/serverData";
-import { isAdminOrAbove } from "@/lib/roles";
+import { hasPerm, PERMS } from "@/lib/roles";
 import Forbidden from "../../../Forbidden";
 import AnnouncementEditLoader from "./AnnouncementEditLoader";

@@ -19,7 +19,7 @@ export default async function AdminAnnouncementEditPage({ params }: PageProps) {
  const { id } = await params;
  const cookie = authCookieHeader(await cookies());
  const me = await getMeCached(cookie || undefined);
-  if (!me.user || !isAdminOrAbove(me.user.role)) {
+  if (!me.user || !hasPerm(me.user, PERMS.ANNOUNCEMENTS)) {
    return <Forbidden text="公告管理仅管理员及以上角色可操作。" />;
  }

--- a/frontend/app/admin/announcements/new/page.tsx
+++ b/frontend/app/admin/announcements/new/page.tsx
@@ -3,7 +3,7 @@ import { Suspense } from "react";
 import { cookies } from "next/headers";
 import { authCookieHeader } from "@/lib/cookies";
 import { getMeCached } from "@/lib/serverData";
-import { isAdminOrAbove } from "@/lib/roles";
+import { hasPerm, PERMS } from "@/lib/roles";
 import Forbidden from "../../Forbidden";
 import AnnouncementComposeClient from "../AnnouncementComposeClient";

@@ -14,7 +14,7 @@ export const metadata: Metadata = {
 export default async function AdminAnnouncementNewPage() {
  const cookie = authCookieHeader(await cookies());
  const me = await getMeCached(cookie || undefined);
-  if (!me.user || !isAdminOrAbove(me.user.role)) {
+  if (!me.user || !hasPerm(me.user, PERMS.ANNOUNCEMENTS)) {
    return <Forbidden text="公告管理仅管理员及以上角色可操作。" />;
  }

--- a/frontend/app/admin/announcements/page.tsx
+++ b/frontend/app/admin/announcements/page.tsx
@@ -5,18 +5,18 @@ import AnnouncementAdmin from "./AnnouncementAdmin";
 import { authCookieHeader } from "@/lib/cookies";
 import { fetchAdminAnnouncements, type Announcement } from "@/lib/api";
 import { getMeCached } from "@/lib/serverData";
-import { isAdminOrAbove } from "@/lib/roles";
+import { hasPerm, PERMS } from "@/lib/roles";
 import Forbidden from "../Forbidden";

 export const metadata: Metadata = {
  title: "站点公告管理",
 };

-// 公告管理仅管理员及以上可用（板块管理员无公告权；后端路由另有守卫）
+// 公告管理：管理员及以上角色自带；超管/站长亦可授予任意账号
 export default async function AdminAnnouncementsPage() {
  const cookie = authCookieHeader(await cookies());
  const me = await getMeCached(cookie || undefined);
-  if (!me.user || !isAdminOrAbove(me.user.role)) {
+  if (!me.user || !hasPerm(me.user, PERMS.ANNOUNCEMENTS)) {
    return <Forbidden text="公告管理仅管理员及以上角色可操作。" />;
  }

--- a/frontend/app/admin/appearance/BgMediaPicker.tsx
+++ b/frontend/app/admin/appearance/BgMediaPicker.tsx
@@ -5,6 +5,7 @@ import { useEffect, useState } from "react";
 import Modal from "@/components/Modal";
 import { apiMyMedia, type MediaAttachment } from "@/lib/api";
 import { mediaURLFitsBackground, type BgSurface } from "@/lib/bg";
+import { isOwnImage, variantURL, widthSrcSet } from "@/lib/responsiveImage";

 const SURFACE_LABEL: Record<BgSurface, string> = {
  site: "前台背景",
@@ -101,7 +102,9 @@ export default function BgMediaPicker({
            >
              {/* eslint-disable-next-line @next/next/no-img-element */}
              <img
-                src={item.url}
+                src={isOwnImage(item.url) ? variantURL(item.url, 160) : item.url}
+                srcSet={isOwnImage(item.url) ? widthSrcSet(item.url, [96, 160, 256, 384]) : undefined}
+                sizes="(max-width:520px) 23vw, 96px"
                alt={`${SURFACE_LABEL[surface]}候选图`}
                className="w-full h-full object-cover"
                loading="lazy"
--- a/frontend/app/admin/content/ContentAdmin.tsx
+++ b/frontend/app/admin/content/ContentAdmin.tsx
@@ -42,7 +42,7 @@ import {
 } from "@/lib/api";
 import { canModerateAuthor } from "@/lib/roles";
 import { formatRelative } from "@/lib/format";
-import { postPath } from "@/lib/urlStyle";
+import { postPath, commentAnchor } from "@/lib/urlStyle";
 import { toast } from "@/lib/toast";
 import { realtime, RT_MODERATION_CHANGED } from "@/lib/realtime";
 import Avatar from "@/components/Avatar";
@@ -692,7 +692,7 @@ export default function ContentAdmin({
                    c.post_title
                  ) : (
                    <Link
-                      href={`${postPath(urlStyle, c.post_id)}#comment-${c.id}`}
+                      href={`${postPath(urlStyle, c.post_id)}${commentAnchor(c.floor, c.is_root, c.id)}`}
                      className="hover:underline"
                      style={{ color: "var(--accent)" }}
                    >
--- a/frontend/app/admin/friend-links/FriendLinksAdmin.tsx
+++ b/frontend/app/admin/friend-links/FriendLinksAdmin.tsx
@@ -22,6 +22,7 @@ import {
  type FriendLinkStatus,
 } from "@/lib/api";
 import { AdminPageHeader, AdminSettingsPage, AdminEmpty } from "@/components/admin";
+import { densitySrcSet, isOwnImage, pickVariantWidth, variantURL } from "@/lib/responsiveImage";

 interface Props {
  initialLinks: FriendLink[];
@@ -237,9 +238,11 @@ export default function FriendLinksAdmin({ initialLinks, initError }: Props) {
                style={{ borderTop: "1px solid var(--line)" }}
              >
                {l.logo_url ? (
+                  // 36px 位：本站图走 48/96 变体；外链保持原样
                  // eslint-disable-next-line @next/next/no-img-element
                  <img
-                    src={l.logo_url}
+                    src={isOwnImage(l.logo_url) ? variantURL(l.logo_url, pickVariantWidth(36)) : l.logo_url}
+                    srcSet={isOwnImage(l.logo_url) ? densitySrcSet(l.logo_url, 36) : undefined}
                    alt=""
                    width={36}
                    height={36}
--- a/frontend/app/admin/layout.tsx
+++ b/frontend/app/admin/layout.tsx
@@ -5,7 +5,7 @@ import { redirect } from "next/navigation";
 import { ShieldAlert } from "lucide-react";
 import { authCookieHeader, REFRESH_COOKIE, CSRF_COOKIE, TOKEN_COOKIE } from "@/lib/cookies";
 import { getMeCached, getPublicSettingsCached } from "@/lib/serverData";
-import { canAccessAdminMessages, isStaff } from "@/lib/roles";
+import { canAccessAdminMessages, hasAnyChannelPerm, isStaff } from "@/lib/roles";
 import AdminShell from "@/components/admin/AdminShell";
 import AdminSessionRecover from "./AdminSessionRecover";

@@ -15,7 +15,7 @@ export const metadata: Metadata = {
 };

 // 权限以 Go 端为唯一判定；此处仅决定管理界面是否直出。
-// 允许：管理角色，或仅有消息管理/群管权限的用户（仅消息菜单可见）。
+// 允许：管理角色 / 消息管理/群管权限 / 任一渠道权限（公告/单页/书库/广告）。
 export default async function AdminLayout({ children }: { children: React.ReactNode }) {
  const cookieStore = await cookies();
  const cookie = authCookieHeader(cookieStore);
@@ -24,7 +24,8 @@ export default async function AdminLayout({ children }: { children: React.ReactN
  const theme = cookieStore.get("j13-theme")?.value === "dark" ? "dark" : "light";

  const allowed =
-    !!me.user && (isStaff(me.user.role) || canAccessAdminMessages(me.user));
+    !!me.user &&
+    (isStaff(me.user.role) || canAccessAdminMessages(me.user) || hasAnyChannelPerm(me.user));

  if (!allowed || !me.user) {
    // 已登录但无后台权限：保留提示卡片
--- a/frontend/app/admin/library/LibraryAdmin.tsx
+++ b/frontend/app/admin/library/LibraryAdmin.tsx
@@ -1,6 +1,6 @@
 "use client";

-import { useMemo, useRef, useState } from "react";
+import { useMemo, useRef, useState, type ChangeEvent } from "react";
 import {
  BookOpen,
  Download,
@@ -17,6 +17,7 @@ import {
  apiAdminCreateLibraryDoc,
  apiAdminDeleteLibraryDoc,
  apiAdminDeleteLibraryFile,
+  apiAdminImportLibraryZip,
  apiAdminListLibraryDocs,
  apiAdminPurgeLibraryDoc,
  apiAdminUpdateLibraryDoc,
@@ -25,17 +26,20 @@ import {
  apiUploadPostImage,
  type LibraryDoc,
  type LibraryFileItem,
+  type LibraryImportReport,
  type LibraryInput,
 } from "@/lib/api";
 import { formatDateTime, formatRelative } from "@/lib/format";
-import { libraryDocPath } from "@/lib/urlStyle";
+import { libraryDocPath, userPath } from "@/lib/urlStyle";
 import { useUrlStyle } from "@/components/SiteBrandProvider";
 import { toast } from "@/lib/toast";
 import ConfirmDialog from "@/components/ConfirmDialog";
+import Avatar from "@/components/Avatar";
 import MarkdownEditor from "@/components/MarkdownEditor";
 import { AdminEmpty, AdminField, AdminPageHeader, AdminStatusChip, AdminSwitch } from "@/components/admin";
 import LibrarySectionsPanel from "./LibrarySectionsPanel";
 import LibraryCoverPicker from "./LibraryCoverPicker";
+import { densitySrcSet, isOwnImage, pickVariantWidth, variantURL } from "@/lib/responsiveImage";

 // 与后端 libraryAllowedExts 保持一致；前端先拦一道，后端仍会校验
 const ALLOWED_EXTS = new Set([
@@ -59,9 +63,12 @@ function formatSize(n: number): string {

 interface DocForm {
  title: string;
+  author: string;
  slug: string;
  description: string;
  cover_url: string;
+  cover_width: number;
+  cover_height: number;
  published: boolean;
  sort_order: number;
  entries_auto: boolean;
@@ -69,9 +76,12 @@ interface DocForm {

 const EMPTY_FORM: DocForm = {
  title: "",
+  author: "",
  slug: "",
  description: "",
  cover_url: "",
+  cover_width: 0,
+  cover_height: 0,
  published: false,
  sort_order: 0,
  entries_auto: false,
@@ -80,9 +90,12 @@ const EMPTY_FORM: DocForm = {
 function formOfDoc(d: LibraryDoc): DocForm {
  return {
    title: d.title,
+    author: d.author ?? "",
    slug: d.slug,
    description: d.description ?? "",
    cover_url: d.cover_url ?? "",
+    cover_width: d.cover_width ?? 0,
+    cover_height: d.cover_height ?? 0,
    published: d.published,
    sort_order: d.sort_order,
    entries_auto: d.entries_auto ?? false,
@@ -145,6 +158,13 @@ export default function LibraryAdmin({
  const [fileDeleteTarget, setFileDeleteTarget] = useState<LibraryFileItem | null>(null);
  const [fileDeleteBusy, setFileDeleteBusy] = useState(false);

+  // 书库导入恢复（上传导出 ZIP）
+  const importInputRef = useRef<HTMLInputElement>(null);
+  const [importing, setImporting] = useState(false);
+  const [importReport, setImportReport] = useState<LibraryImportReport | null>(null);
+  // create 模式遇到 conflict 时保留 File，供确认后 overwrite 重传
+  const [importOverwrite, setImportOverwrite] = useState<{ file: File; count: number } | null>(null);
+
  // 条目删除（软删）与彻底删除
  const [docDeleteTarget, setDocDeleteTarget] = useState<LibraryDoc | null>(null);
  const [docDeleteBusy, setDocDeleteBusy] = useState(false);
@@ -170,6 +190,34 @@ export default function LibraryAdmin({
    }
  }

+  async function runImport(file: File, mode: "create" | "overwrite") {
+    setImporting(true);
+    setImportReport(null);
+    try {
+      const rep = await apiAdminImportLibraryZip(file, mode);
+      setImportReport(rep);
+      const okN = rep.imported.length;
+      const failN = rep.failed.length;
+      if (okN > 0) toast(`成功导入 ${okN} 本书${failN ? `，${failN} 本未导入` : ""}`, "ok");
+      else toast("没有书籍被导入，请查看失败明细", "error");
+      await reload();
+      if (mode === "create") {
+        const conflicts = rep.failed.filter((f) => f.reason === "conflict").length;
+        if (conflicts > 0) setImportOverwrite({ file, count: conflicts });
+      }
+    } catch (e) {
+      toast(e instanceof Error ? e.message : "导入失败");
+    } finally {
+      setImporting(false);
+    }
+  }
+
+  function onPickImportFile(e: ChangeEvent<HTMLInputElement>) {
+    const file = e.target.files?.[0];
+    e.target.value = ""; // 允许重选同一文件
+    if (file) void runImport(file, "create");
+  }
+
  function openNew() {
    setForm(EMPTY_FORM);
    setSnapshot(JSON.stringify(EMPTY_FORM));
@@ -221,8 +269,11 @@ export default function LibraryAdmin({
      const input: LibraryInput = {
        slug,
        title,
+        author: form.author.trim(),
        description: form.description,
        cover_url: form.cover_url.trim(),
+        cover_width: form.cover_width,
+        cover_height: form.cover_height,
        published: form.published,
        sort_order: form.sort_order,
        entries_auto: form.entries_auto,
@@ -250,9 +301,13 @@ export default function LibraryAdmin({
    if (!file) return;
    setCoverBusy(true);
    try {
-      const res = await apiUploadPostImage(file);
+      const res = await apiUploadPostImage(file, undefined, "library_cover");
      if (res.url) {
-        patchForm({ cover_url: res.url });
+        patchForm({
+          cover_url: res.url,
+          cover_width: res.attachment?.width ?? 0,
+          cover_height: res.attachment?.height ?? 0,
+        });
      } else {
        setFormError(res.error || "封面上传失败");
      }
@@ -267,8 +322,8 @@ export default function LibraryAdmin({
  async function pickCoverFromMedia(attachmentId: number) {
    setCoverBusy(true);
    try {
-      const url = await apiLibraryCoverFromMedia(attachmentId);
-      patchForm({ cover_url: url });
+      const { url, width, height } = await apiLibraryCoverFromMedia(attachmentId);
+      patchForm({ cover_url: url, cover_width: width, cover_height: height });
    } catch (e) {
      setFormError(e instanceof Error ? e.message : "选用图库图片失败");
    } finally {
@@ -374,17 +429,103 @@ export default function LibraryAdmin({
        title="书库管理"
        description="书籍、文档与页面作品。书籍由介绍、目录与章节正文组成，像书一样阅读；附件仅提供下载分发。"
        actions={
-          <button
-            type="button"
-            className="btn btn-primary"
-            onClick={() => guardNav(openNew)}
-            disabled={saving}
-          >
-            <Plus size={15} /> 新建条目
-          </button>
+          <>
+            <a
+              href="/api/admin/library/export"
+              className="btn btn-ghost"
+              title="把全部书籍打包为 ZIP（介绍、章节、附件与封面），用于迁移或备份"
+            >
+              <Download size={15} aria-hidden />
+              导出全部
+            </a>
+            <button
+              type="button"
+              className="btn btn-ghost"
+              onClick={() => importInputRef.current?.click()}
+              disabled={importing}
+              title="上传导出的 ZIP 备份包，恢复书籍（介绍、章节、附件与封面）"
+            >
+              {importing ? (
+                <Loader2 size={15} className="animate-spin" aria-hidden />
+              ) : (
+                <Upload size={15} aria-hidden />
+              )}
+              {importing ? "导入中…" : "导入恢复"}
+            </button>
+            <input
+              ref={importInputRef}
+              type="file"
+              accept=".zip,application/zip"
+              className="hidden"
+              onChange={onPickImportFile}
+            />
+            <button
+              type="button"
+              className="btn btn-primary"
+              onClick={() => guardNav(openNew)}
+              disabled={saving}
+            >
+              <Plus size={15} /> 新建条目
+            </button>
+          </>
        }
      />

+      {importReport ? (
+        <div
+          className="panel mx-3.5 sm:mx-4 my-3 px-4 py-3 text-[13px]"
+          role="status"
+          style={{ borderColor: "var(--line)" }}
+        >
+          <div className="flex items-center gap-2">
+            <strong style={{ color: "var(--ink)" }}>
+              导入完成：成功 {importReport.imported.length} 本
+              （新建 {importReport.imported.filter((i) => i.action === "created").length} / 覆盖{" "}
+              {importReport.imported.filter((i) => i.action === "overwritten").length}），失败{" "}
+              {importReport.failed.length} 本
+            </strong>
+            <button
+              type="button"
+              className="ml-auto btn btn-ghost"
+              style={{ padding: "2px 6px" }}
+              onClick={() => setImportReport(null)}
+              aria-label="关闭导入结果"
+            >
+              <X size={14} aria-hidden />
+            </button>
+          </div>
+          {importReport.failed.length > 0 ? (
+            <ul className="mt-2 flex flex-col gap-1">
+              {importReport.failed.map((f, i) => (
+                <li key={`${f.slug}-${i}`} className="meta flex flex-wrap items-baseline gap-x-2">
+                  <span style={{ color: "var(--ink-2)" }}>
+                    {f.title || f.slug}
+                    {f.slug ? `（${f.slug}）` : ""}
+                  </span>
+                  <span
+                    style={{
+                      color:
+                        f.reason === "conflict" || f.reason === "deleted"
+                          ? "var(--warn, #b45309)"
+                          : "var(--danger, #b91c1c)",
+                    }}
+                  >
+                    {f.reason === "conflict"
+                      ? "同名书籍已存在，可覆盖导入"
+                      : f.reason === "deleted"
+                        ? "地址被已删除条目占用，需先彻底删除"
+                        : f.reason === "invalid"
+                          ? "备份数据不受支持"
+                          : "导入失败"}
+                  </span>
+                  <span>{f.error}</span>
+                </li>
+              ))}
+            </ul>
+          ) : null}
+        </div>
+      ) : null}
+
      <div
        className="admin-library-split"
        data-view={editorOpen ? "editor" : "list"}
@@ -435,9 +576,11 @@ export default function LibraryAdmin({
                        }}
                      >
                        {d.cover_url ? (
+                          // 36px 封面位：本站图走 48/96 变体
                          // eslint-disable-next-line @next/next/no-img-element
                          <img
-                            src={d.cover_url}
+                            src={isOwnImage(d.cover_url) ? variantURL(d.cover_url, pickVariantWidth(36)) : d.cover_url}
+                            srcSet={isOwnImage(d.cover_url) ? densitySrcSet(d.cover_url, 36) : undefined}
                            alt=""
                            className="w-9 h-9 rounded-lg object-cover shrink-0"
                            style={{ border: "1px solid var(--line)" }}
@@ -560,6 +703,16 @@ export default function LibraryAdmin({
                    ? `${editingDoc.sections?.length ?? 0} 章节 · ${editingDoc.files?.length ?? 0} 附件`
                    : ""}
                </span>
+                {typeof editingId === "number" ? (
+                  <a
+                    href={`/api/admin/library/docs/${editingId}/export`}
+                    className="btn btn-line btn-sm shrink-0"
+                    title="导出本书为 ZIP（介绍、章节、附件与本地封面），用于迁移或备份"
+                  >
+                    <Download size={13} aria-hidden />
+                    导出备份
+                  </a>
+                ) : null}
              </div>

              {/* 书籍信息 tab（两个 tab 均保持挂载，避免章节编辑状态丢失）。
@@ -586,6 +739,15 @@ export default function LibraryAdmin({
                        className="admin-doc-title"
                      />

+                      <AdminField
+                        id="lib-author"
+                        label="作者"
+                        maxLength={100}
+                        value={form.author}
+                        onChange={(author) => patchForm({ author })}
+                        placeholder="作者或编著者，多位可用逗号分隔（可选）"
+                      />
+
                      <div className="admin-doc-field">
                        <label className="admin-doc-label" htmlFor="lib-slug">
                          访问地址
@@ -628,6 +790,7 @@ export default function LibraryAdmin({
                          placeholder="条目介绍，支持 Markdown…"
                          rows={12}
                          ariaLabel="条目介绍"
+                          uploadSource="library_content"
                        />
                      </div>
                    </div>
@@ -636,56 +799,58 @@ export default function LibraryAdmin({
                    <aside className="flex flex-col gap-4 lg:min-h-0">
                      <div className="admin-doc-field">
                        <p className="admin-doc-label">封面（可选）</p>
-                        <div className="flex items-center gap-2.5">
+                        <div className="flex flex-col gap-2">
                          {form.cover_url ? (
                            // eslint-disable-next-line @next/next/no-img-element
                            <img
-                              src={form.cover_url}
+                              src={isOwnImage(form.cover_url) ? variantURL(form.cover_url, 256) : form.cover_url}
                              alt="封面预览"
-                              className="w-12 h-12 rounded-lg object-cover shrink-0"
+                              className="w-full h-32 rounded-xl object-cover"
                              style={{ border: "1px solid var(--line)" }}
                            />
                          ) : (
                            <button
                              type="button"
-                              className="w-12 h-12 rounded-lg flex items-center justify-center shrink-0"
+                              className="w-full h-32 rounded-xl flex flex-col items-center justify-center gap-1.5"
                              style={{ border: "1px dashed var(--control-border)" }}
                              aria-label="上传封面"
                              onClick={() => coverInputRef.current?.click()}
                            >
-                              <ImagePlus size={16} style={{ color: "var(--ink-3)" }} aria-hidden />
+                              <ImagePlus size={20} style={{ color: "var(--ink-3)" }} aria-hidden />
+                              <span className="text-[11.5px]" style={{ color: "var(--ink-3)" }}>
+                                点击上传封面
+                              </span>
                            </button>
                          )}
-                          <div className="flex flex-col gap-1">
-                            <div className="flex gap-1.5">
-                              <button
-                                type="button"
-                                className="btn btn-line btn-sm flex-1"
-                                disabled={coverBusy}
-                                onClick={() => coverInputRef.current?.click()}
-                              >
-                                {coverBusy ? (
-                                  <Loader2 size={13} className="animate-spin" aria-hidden />
-                                ) : (
-                                  <ImagePlus size={13} aria-hidden />
-                                )}
-                                {form.cover_url ? "更换" : "上传"}
-                              </button>
-                              <button
-                                type="button"
-                                className="btn btn-line btn-sm flex-1"
-                                disabled={coverBusy}
-                                onClick={() => setCoverPickerOpen(true)}
-                              >
-                                <Images size={13} aria-hidden />
-                                图库
-                              </button>
-                            </div>
+                          <div className="flex items-center gap-1.5">
+                            <button
+                              type="button"
+                              className="btn btn-line btn-sm"
+                              disabled={coverBusy}
+                              onClick={() => coverInputRef.current?.click()}
+                            >
+                              {coverBusy ? (
+                                <Loader2 size={13} className="animate-spin" aria-hidden />
+                              ) : (
+                                <ImagePlus size={13} aria-hidden />
+                              )}
+                              {form.cover_url ? "更换" : "上传"}
+                            </button>
+                            <button
+                              type="button"
+                              className="btn btn-line btn-sm"
+                              disabled={coverBusy}
+                              onClick={() => setCoverPickerOpen(true)}
+                            >
+                              <Images size={13} aria-hidden />
+                              图库
+                            </button>
                            {form.cover_url ? (
                              <button
                                type="button"
-                                className="admin-doc-textbtn"
-                                onClick={() => patchForm({ cover_url: "" })}
+                                className="admin-doc-textbtn ml-auto"
+                                style={{ minHeight: 0, minWidth: 0, padding: "1px 6px", fontSize: 12 }}
+                                onClick={() => patchForm({ cover_url: "", cover_width: 0, cover_height: 0 })}
                              >
                                移除
                              </button>
@@ -749,6 +914,30 @@ export default function LibraryAdmin({
                        <p className="admin-doc-hint">数字越小越靠前。</p>
                      </div>

+                      {typeof editingId === "number" && editingDoc?.creator ? (
+                        <div className="admin-doc-field">
+                          <p className="admin-doc-label">创建者</p>
+                          <a
+                            href={userPath(urlStyle, editingDoc.creator.id)}
+                            target="_blank"
+                            rel="noopener noreferrer"
+                            className="inline-flex items-center gap-2 text-[13px] font-medium max-w-full"
+                            style={{ color: "var(--ink)" }}
+                            title={`@${editingDoc.creator.username}`}
+                          >
+                            <Avatar
+                              size={22}
+                              name={editingDoc.creator.nickname || editingDoc.creator.username}
+                              src={editingDoc.creator.avatar}
+                            />
+                            <span className="truncate">
+                              {editingDoc.creator.nickname || editingDoc.creator.username}
+                            </span>
+                          </a>
+                          <p className="admin-doc-hint">条目创建后归属不变。</p>
+                        </div>
+                      ) : null}
+
                      {/* 附件管理：长列表列内滚动 */}
                      <div className="admin-doc-field flex flex-col lg:flex-1 lg:min-h-0">
                        <p className="admin-doc-label shrink-0">
@@ -956,6 +1145,27 @@ export default function LibraryAdmin({
        </section>
      </div>

+      {/* 导入遇到同名书籍：确认后覆盖重传（保留同一 File） */}
+      <ConfirmDialog
+        open={!!importOverwrite}
+        title="覆盖导入同名书籍？"
+        message={
+          importOverwrite
+            ? `备份包中有 ${importOverwrite.count} 本书的地址已被现有书籍占用。选择覆盖将用备份包整体替换这些书籍的介绍、章节、附件与封面，现有内容不可恢复；其余书籍正常新建。`
+            : ""
+        }
+        danger
+        busy={importing}
+        confirmLabel="覆盖导入"
+        cancelLabel="保留现有"
+        onCancel={() => !importing && setImportOverwrite(null)}
+        onConfirm={() => {
+          const pending = importOverwrite;
+          setImportOverwrite(null);
+          if (pending) void runImport(pending.file, "overwrite");
+        }}
+      />
+
      {/* 未保存关闭/切换确认 */}
      <ConfirmDialog
        open={!!pendingNav}
--- a/frontend/app/admin/library/LibraryCoverPicker.tsx
+++ b/frontend/app/admin/library/LibraryCoverPicker.tsx
@@ -4,8 +4,35 @@ import { Images, Loader2 } from "lucide-react";
 import { useEffect, useState } from "react";
 import Modal from "@/components/Modal";
 import { apiMyMedia, type MediaAttachment } from "@/lib/api";
+import { isOwnImage, variantURL, widthSrcSet } from "@/lib/responsiveImage";

-/** 书籍封面图库选择弹窗：列出本人媒体库图片，选中后由父组件复制一份作封面素材 */
+/** 来源标签映射 */
+const SOURCE_LABELS: Record<string, string> = {
+  library_cover: "书籍封面",
+  library_content: "书籍内容",
+  post: "帖子插图",
+};
+
+function sourceLabel(source?: string): string {
+  return SOURCE_LABELS[source || "post"] || source || "帖子插图";
+}
+
+/** 按来源分组（library_cover 优先，其次 library_content，最后 post/其他） */
+function groupBySource(items: MediaAttachment[]): [string, MediaAttachment[]][] {
+  const groups = new Map<string, MediaAttachment[]>();
+  for (const item of items) {
+    const key = item.source || "post";
+    if (!groups.has(key)) groups.set(key, []);
+    groups.get(key)!.push(item);
+  }
+  // 按优先级排序
+  const order = ["library_cover", "library_content", "post"];
+  return Array.from(groups.entries()).sort(
+    ([a], [b]) => order.indexOf(a) - order.indexOf(b)
+  );
+}
+
+/** 书籍封面图库选择弹窗：列出本人媒体库图片，按来源分组 */
 export default function LibraryCoverPicker({
  open,
  onClose,
@@ -45,13 +72,15 @@ export default function LibraryCoverPicker({
    };
  }, [open]);

+  const groups = groupBySource(items);
+
  return (
    <Modal
      open={open}
      title="从图库选择封面"
-      description="选择后会复制一份作为封面素材，之后删除原图不影响封面。"
+      description="已选作封面的图片会单独分组，再次选择直接复用。"
      onClose={onClose}
-      maxWidthClass="max-w-lg"
+      maxWidthClass="max-w-2xl"
      dismissOnOverlay
    >
      {loading ? (
@@ -67,28 +96,52 @@ export default function LibraryCoverPicker({
          图库还没有图片。上传封面或发帖插图后，会自动出现在这里。
        </p>
      ) : (
-        <div className="grid grid-cols-4 sm:grid-cols-5 gap-2 max-h-[46vh] overflow-y-auto">
-          {items.map((item) => (
-            <button
-              key={item.id}
-              type="button"
-              onClick={() => {
-                onPick(item);
-                onClose();
-              }}
-              className="relative group aspect-square rounded-xl overflow-hidden"
-              style={{ boxShadow: "0 0 0 1px var(--line)", background: "var(--panel-2)" }}
-              data-tip="复制一份用作封面"
-            >
-              {/* eslint-disable-next-line @next/next/no-img-element */}
-              <img src={item.url} alt="图库候选封面" className="w-full h-full object-contain" loading="lazy" />
-              <span
-                className="pointer-events-none absolute inset-0 flex items-center justify-center opacity-0 group-hover:opacity-100"
-                style={{ background: "color-mix(in srgb, var(--ink) 40%, transparent)", color: "#fff" }}
+        <div className="flex flex-col gap-5 max-h-[60vh] overflow-y-auto">
+          {groups.map(([source, groupItems]) => (
+            <section key={source}>
+              <h4
+                className="text-[11.5px] font-bold tracking-wide uppercase mb-2 px-0.5"
+                style={{ color: "var(--ink-3)" }}
              >
-                <Images size={14} />
-              </span>
-            </button>
+                {sourceLabel(source)}
+                <span className="ml-1.5 font-normal opacity-70">({groupItems.length})</span>
+              </h4>
+              <div className="grid grid-cols-4 sm:grid-cols-5 gap-2">
+                {groupItems.map((item) => (
+                  <button
+                    key={item.id}
+                    type="button"
+                    onClick={() => {
+                      onPick(item);
+                      onClose();
+                    }}
+                    className="relative group aspect-square rounded-xl overflow-hidden"
+                    style={{ boxShadow: "0 0 0 1px var(--line)", background: "var(--panel-2)" }}
+                    data-tip={
+                      item.source === "library_cover"
+                        ? "已作封面，点击直接复用"
+                        : "复制一份用作封面"
+                    }
+                  >
+                    {/* eslint-disable-next-line @next/next/no-img-element */}
+                    <img
+                      src={isOwnImage(item.url) ? variantURL(item.url, 160) : item.url}
+                      srcSet={isOwnImage(item.url) ? widthSrcSet(item.url, [96, 160, 256, 384]) : undefined}
+                      sizes="(max-width:520px) 23vw, 96px"
+                      alt="图库候选封面"
+                      className="w-full h-full object-contain"
+                      loading="lazy"
+                    />
+                    <span
+                      className="pointer-events-none absolute inset-0 flex items-center justify-center opacity-0 group-hover:opacity-100"
+                      style={{ background: "color-mix(in srgb, var(--ink) 40%, transparent)", color: "#fff" }}
+                    >
+                      <Images size={14} />
+                    </span>
+                  </button>
+                ))}
+              </div>
+            </section>
          ))}
        </div>
      )}
--- a/frontend/app/admin/library/LibrarySectionsPanel.tsx
+++ b/frontend/app/admin/library/LibrarySectionsPanel.tsx
@@ -410,6 +410,7 @@ export default function LibrarySectionsPanel({
                  placeholder="本章正文，支持 Markdown…"
                  rows={16}
                  ariaLabel="章节正文"
+                  uploadSource="library_content"
                />
              </div>
            </div>
--- a/frontend/app/admin/library/page.tsx
+++ b/frontend/app/admin/library/page.tsx
@@ -5,7 +5,7 @@ import LibraryAdmin from "./LibraryAdmin";
 import { authCookieHeader } from "@/lib/cookies";
 import { fetchAdminLibraryDocs, type LibraryDoc } from "@/lib/api";
 import { getMeCached } from "@/lib/serverData";
-import { isAdminOrAbove } from "@/lib/roles";
+import { hasPerm, PERMS } from "@/lib/roles";
 import Forbidden from "../Forbidden";

 export const metadata: Metadata = {
@@ -15,7 +15,7 @@ export const metadata: Metadata = {
 export default async function AdminLibraryPage() {
  const cookie = authCookieHeader(await cookies());
  const me = await getMeCached(cookie || undefined);
-  if (!me.user || !isAdminOrAbove(me.user.role)) {
+  if (!me.user || !hasPerm(me.user, PERMS.LIBRARY)) {
    return <Forbidden text="书库管理仅管理员及以上角色可操作。" />;
  }

--- a/frontend/app/admin/media/MediaLibrary.tsx
+++ b/frontend/app/admin/media/MediaLibrary.tsx
@@ -5,6 +5,7 @@ import { Images, Copy, ExternalLink, Eye, Check } from "lucide-react";
 import Modal from "@/components/Modal";
 import AdminEmpty from "@/components/admin/AdminEmpty";
 import type { MediaLibraryItem } from "@/lib/api";
+import { isOwnImage, variantURL, widthSrcSet } from "@/lib/responsiveImage";

 function formatBytes(n: number): string {
  if (n < 1024) return `${n} B`;
@@ -24,10 +25,11 @@ function formatDims(item: MediaLibraryItem): string {
  return "—";
 }

-/** 网格缩略图：本地图走服务端缩略接口（磁盘缓存），远程对象直连原图（头像类本身小） */
+/** 网格缩略图：本站图走统一变体端点（磁盘缓存，256 档）；非本站图原样返回 */
 function thumbSrc(item: MediaLibraryItem): string {
-  if (item.url.startsWith("/uploads/")) {
-    return `/api/admin/media-library/thumb?u=${encodeURIComponent(item.url)}`;
+  // 网格缩略走统一变体端点（256 档）；非本站图原样返回
+  if (isOwnImage(item.url)) {
+    return variantURL(item.url, 256);
  }
  return item.url;
 }
@@ -143,6 +145,8 @@ export default function MediaLibrary({
            <span className="block relative aspect-square overflow-hidden">
              <img
                src={thumbSrc(item)}
+                srcSet={isOwnImage(item.url) ? widthSrcSet(item.url, [160, 256, 384, 512]) : undefined}
+                sizes="(min-width:1280px) 16vw, (min-width:1024px) 25vw, (min-width:640px) 33vw, 50vw"
                alt={item.name}
                loading="lazy"
                className="absolute inset-0 w-full h-full object-cover"
@@ -175,7 +179,8 @@ export default function MediaLibrary({
      <Modal
        open={active !== null}
        onClose={() => setActive(null)}
-        title={active?.name ?? ""}
+        title={<span className="break-all">{active?.name ?? ""}</span>}
+        ariaLabel={active?.name ?? ""}
        description={active ? `${active.category_name}${active.uploader ? ` · 上传者 ${active.uploader}` : ""}` : undefined}
        maxWidthClass="max-w-2xl"
        dismissOnOverlay
@@ -214,6 +219,14 @@ export default function MediaLibrary({
                ["格式", active.mime],
                ["上传者", active.uploader || "—"],
                ["时间", formatTime(active.uploaded_at)],
+                ...(active.ref_count && active.ref_count > 1
+                  ? [
+                      [
+                        "引用",
+                        `${active.ref_count} 次上传 · 去重节省 ${formatBytes(active.size * (active.ref_count - 1))}`,
+                      ],
+                    ]
+                  : []),
              ].map(([k, v]) => (
                <div key={k} className="flex items-baseline gap-2 min-w-0">
                  <dt className="meta shrink-0 w-11 text-right">{k}</dt>
--- a/frontend/app/admin/pages/[id]/edit/page.tsx
+++ b/frontend/app/admin/pages/[id]/edit/page.tsx
@@ -3,7 +3,7 @@ import { Suspense } from "react";
 import { cookies } from "next/headers";
 import { authCookieHeader } from "@/lib/cookies";
 import { getMeCached } from "@/lib/serverData";
-import { isAdminOrAbove } from "@/lib/roles";
+import { hasPerm, PERMS } from "@/lib/roles";
 import Forbidden from "../../../Forbidden";
 import PageEditLoader from "./PageEditLoader";

@@ -19,7 +19,7 @@ export default async function AdminPageEditPage({ params }: PageProps) {
  const { id } = await params;
  const cookie = authCookieHeader(await cookies());
  const me = await getMeCached(cookie || undefined);
-  if (!me.user || !isAdminOrAbove(me.user.role)) {
+  if (!me.user || !hasPerm(me.user, PERMS.PAGES)) {
    return <Forbidden text="单页管理仅管理员及以上角色可操作。" />;
  }

--- a/frontend/app/admin/pages/new/page.tsx
+++ b/frontend/app/admin/pages/new/page.tsx
@@ -3,7 +3,7 @@ import { Suspense } from "react";
 import { cookies } from "next/headers";
 import { authCookieHeader } from "@/lib/cookies";
 import { getMeCached } from "@/lib/serverData";
-import { isAdminOrAbove } from "@/lib/roles";
+import { hasPerm, PERMS } from "@/lib/roles";
 import Forbidden from "../../Forbidden";
 import PageComposeClient from "../PageComposeClient";

@@ -14,7 +14,7 @@ export const metadata: Metadata = {
 export default async function AdminPageNewPage() {
  const cookie = authCookieHeader(await cookies());
  const me = await getMeCached(cookie || undefined);
-  if (!me.user || !isAdminOrAbove(me.user.role)) {
+  if (!me.user || !hasPerm(me.user, PERMS.PAGES)) {
    return <Forbidden text="单页管理仅管理员及以上角色可操作。" />;
  }

--- a/frontend/app/admin/pages/page.tsx
+++ b/frontend/app/admin/pages/page.tsx
@@ -5,7 +5,7 @@ import PagesAdmin from "./PagesAdmin";
 import { authCookieHeader } from "@/lib/cookies";
 import { fetchAdminSitePages, type SitePage } from "@/lib/api";
 import { getMeCached } from "@/lib/serverData";
-import { isAdminOrAbove } from "@/lib/roles";
+import { hasPerm, PERMS } from "@/lib/roles";
 import Forbidden from "../Forbidden";

 export const metadata: Metadata = {
@@ -15,7 +15,7 @@ export const metadata: Metadata = {
 export default async function AdminPagesPage() {
  const cookie = authCookieHeader(await cookies());
  const me = await getMeCached(cookie || undefined);
-  if (!me.user || !isAdminOrAbove(me.user.role)) {
+  if (!me.user || !hasPerm(me.user, PERMS.PAGES)) {
    return <Forbidden text="单页管理仅管理员及以上角色可操作。" />;
  }

--- a/frontend/app/admin/settings/BasicIdentityPanel.tsx
+++ b/frontend/app/admin/settings/BasicIdentityPanel.tsx
@@ -2,7 +2,7 @@

 import { X } from "lucide-react";
 import { useEffect, useRef, useState } from "react";
-import { AdminField, AdminSettingsActions, AdminSettingsGroup } from "@/components/admin";
+import { AdminField, AdminSettingsActions, AdminSettingsGroup, AdminSwitch } from "@/components/admin";
 import { apiUpdateSiteSettings, apiOperations, type PublicSettings } from "@/lib/api";
 import { BRAND_LIMITS, runeCount, siteDocumentTitle } from "@/lib/brand";
 import { toast } from "@/lib/toast";
@@ -25,6 +25,7 @@ export default function BasicIdentityPanel({
  }, []);
  const [wordmark, setWordmark] = useState(initial.site_wordmark);
  const [slogan, setSlogan] = useState(initial.site_slogan);
+  const [sloganVisible, setSloganVisible] = useState(initial.brand_slogan_visible);
  const [desc, setDesc] = useState(initial.site_description);
  const [keywords, setKeywords] = useState<string[]>(initial.site_keywords);
  const [kwInput, setKwInput] = useState("");
@@ -32,6 +33,7 @@ export default function BasicIdentityPanel({
    name: initial.site_name,
    wordmark: initial.site_wordmark,
    slogan: initial.site_slogan,
+    sloganVisible: initial.brand_slogan_visible,
    desc: initial.site_description,
    keywords: initial.site_keywords,
  });
@@ -44,6 +46,7 @@ export default function BasicIdentityPanel({
    name.trim() !== saved.name ||
    wordmark.trim() !== saved.wordmark ||
    slogan.trim() !== saved.slogan ||
+    sloganVisible !== saved.sloganVisible ||
    desc.trim() !== saved.desc ||
    JSON.stringify(keywords) !== JSON.stringify(saved.keywords);

@@ -85,6 +88,7 @@ export default function BasicIdentityPanel({
    setName(saved.name);
    setWordmark(saved.wordmark);
    setSlogan(saved.slogan);
+    setSloganVisible(saved.sloganVisible);
    setDesc(saved.desc);
    setKeywords([...saved.keywords]);
    setKwInput("");
@@ -98,6 +102,7 @@ export default function BasicIdentityPanel({
      name: name.trim(),
      wordmark: wordmark.trim(),
      slogan: slogan.trim(),
+      sloganVisible,
      desc: desc.trim(),
      keywords: [...keywords],
    };
@@ -115,6 +120,7 @@ export default function BasicIdentityPanel({
        site_name: snap.name,
        site_wordmark: snap.wordmark,
        site_slogan: snap.slogan,
+        brand_slogan_visible: snap.sloganVisible,
        site_description: snap.desc,
        site_keywords: snap.keywords,
      });
@@ -123,12 +129,14 @@ export default function BasicIdentityPanel({
        name: res.site_name,
        wordmark: res.site_wordmark,
        slogan: res.site_slogan,
+        sloganVisible: res.brand_slogan_visible,
        desc: res.site_description,
        keywords: res.site_keywords,
      });
      setName((v) => (v.trim() === snap.name ? res.site_name : v));
      setWordmark((v) => (v.trim() === snap.wordmark ? res.site_wordmark : v));
      setSlogan((v) => (v.trim() === snap.slogan ? res.site_slogan : v));
+      setSloganVisible((v) => (v === snap.sloganVisible ? res.brand_slogan_visible : v));
      setDesc((v) => (v.trim() === snap.desc ? res.site_description : v));
      setKeywords((prev) =>
        JSON.stringify(prev) === JSON.stringify(snap.keywords) ? res.site_keywords : prev,
@@ -199,18 +207,49 @@ export default function BasicIdentityPanel({
          />
        </div>

-        <AdminField
-          id="site-slogan"
-          label="标语"
-          className="admin-identity-field"
-          maxLength={BRAND_LIMITS.slogan}
-          value={slogan}
-          onChange={(v) => {
-            setSlogan(v);
-            clearSaveError();
-          }}
-          placeholder="技术分享与讨论"
-        />
+        <div className="admin-identity-field">
+          <div className="admin-field-head">
+            <label className="field-label" htmlFor="site-slogan">
+              标语
+            </label>
+            <span className="admin-field-count" aria-hidden>
+              {slogan.length}/{BRAND_LIMITS.slogan}
+            </span>
+          </div>
+          <div
+            className="flex items-center gap-2 mb-2"
+            title={slogan.trim() ? "在页眉站名下方显示副标题" : "先填写标语后可开启"}
+          >
+            <AdminSwitch
+              checked={sloganVisible}
+              disabled={!slogan.trim()}
+              onChange={() => {
+                setSloganVisible((v) => !v);
+                clearSaveError();
+              }}
+              label="页眉显示标语"
+            />
+            <span
+              className="text-[12px]"
+              style={{ color: slogan.trim() ? "var(--ink-2)" : "var(--ink-3)" }}
+            >
+              页眉显示标语
+            </span>
+          </div>
+          <div className="admin-field-shell">
+            <input
+              id="site-slogan"
+              className="admin-field-input"
+              maxLength={BRAND_LIMITS.slogan}
+              value={slogan}
+              onChange={(e) => {
+                setSlogan(e.target.value);
+                clearSaveError();
+              }}
+              placeholder="技术分享与讨论"
+            />
+          </div>
+        </div>
        <p className="admin-identity-title-preview" aria-live="polite">
          浏览器标题预览 · <strong>{preview}</strong>
        </p>
--- a/frontend/app/admin/settings/BrandMediaPicker.tsx
+++ b/frontend/app/admin/settings/BrandMediaPicker.tsx
@@ -3,8 +3,9 @@
 import { Images, Loader2 } from "lucide-react";
 import { useEffect, useState } from "react";
 import Modal from "@/components/Modal";
-import { apiMyMedia, type MediaAttachment } from "@/lib/api";
-import { mediaURLFitsSlot, type BrandSlot } from "@/lib/brand";
+import { apiAdminMediaLibrary, apiMyMedia } from "@/lib/api";
+import { normalizeBrandURL, type BrandSlot } from "@/lib/brand";
+import { isOwnImage, variantURL, widthSrcSet } from "@/lib/responsiveImage";

 const SLOT_LABEL: Record<BrandSlot, string> = {
  logo_light: "浅色 Logo",
@@ -12,6 +13,13 @@ const SLOT_LABEL: Record<BrandSlot, string> = {
  favicon: "Favicon",
 };

+/** 选图条目：本人附件带 attachmentId；品牌目录历史图仅 URL（已在品牌目录，无需复制） */
+export type BrandPickItem = {
+  key: string;
+  url: string;
+  attachmentId: number | null;
+};
+
 export default function BrandMediaPicker({
  open,
  slot,
@@ -21,9 +29,9 @@ export default function BrandMediaPicker({
  open: boolean;
  slot: BrandSlot;
  onClose: () => void;
-  onPick: (item: MediaAttachment) => void;
+  onPick: (item: BrandPickItem) => void;
 }) {
-  const [items, setItems] = useState<MediaAttachment[]>([]);
+  const [items, setItems] = useState<BrandPickItem[]>([]);
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState("");

@@ -32,16 +40,29 @@ export default function BrandMediaPicker({
    let cancelled = false;
    setLoading(true);
    setError("");
-    void apiMyMedia()
-      .then((res) => {
+    // 本人附件 + 媒体库盘点里的品牌目录历史图（品牌图不落附件，需合并展示）
+    Promise.all([apiMyMedia(), apiAdminMediaLibrary().catch(() => null)])
+      .then(([mediaRes, libRes]) => {
        if (cancelled) return;
-        if (res.error) {
-          setError(res.error);
+        if (mediaRes.error) {
+          setError(mediaRes.error);
          setItems([]);
          return;
        }
-        const all = res.attachments || [];
-        setItems(all.filter((item) => mediaURLFitsSlot(slot, item.url)));
+        const out: BrandPickItem[] = (mediaRes.attachments || []).map((a) => ({
+          key: `att-${a.id}`,
+          url: a.url,
+          attachmentId: a.id,
+        }));
+        const seen = new Set(out.map((i) => i.url));
+        for (const it of libRes?.items || []) {
+          if (it.category !== "brand") continue;
+          if (!normalizeBrandURL(slot, it.url)) continue;
+          if (seen.has(it.url)) continue;
+          seen.add(it.url);
+          out.unshift({ key: `brand-${it.url}`, url: it.url, attachmentId: null });
+        }
+        setItems(out);
      })
      .catch(() => {
        if (!cancelled) setError("加载媒体库失败");
@@ -58,7 +79,7 @@ export default function BrandMediaPicker({
    <Modal
      open={open}
      title={`从媒体库选择 · ${SLOT_LABEL[slot]}`}
-      description="只列出格式符合的图片。保存后会复制一份到品牌目录，之后删除原图不会影响 Logo。"
+      description="位图选中后进入裁剪并转成 WebP；SVG / ICO 与历史品牌图直接引用，之后删除原图不会影响 Logo。"
      onClose={onClose}
      maxWidthClass="max-w-lg"
      dismissOnOverlay
@@ -72,12 +93,12 @@ export default function BrandMediaPicker({
          {error}
        </p>
      ) : items.length === 0 ? (
-        <p className="meta text-[13px] py-6 text-center">没有可用图片。Logo 需要 PNG / WebP / SVG，Favicon 还可选 ICO。</p>
+        <p className="meta text-[13px] py-6 text-center">媒体库还没有图片，先上传一张吧。</p>
      ) : (
        <div className="grid grid-cols-4 sm:grid-cols-5 gap-2">
          {items.map((item) => (
            <button
-              key={item.id}
+              key={item.key}
              type="button"
              onClick={() => {
                onPick(item);
@@ -88,7 +109,14 @@ export default function BrandMediaPicker({
              data-tip="用作草稿预览，点保存后才生效"
            >
              {/* eslint-disable-next-line @next/next/no-img-element */}
-              <img src={item.url} alt={`${SLOT_LABEL[slot]}候选图`} className="w-full h-full object-contain" loading="lazy" />
+              <img
+                src={isOwnImage(item.url) ? variantURL(item.url, 160) : item.url}
+                srcSet={isOwnImage(item.url) ? widthSrcSet(item.url, [96, 160, 256, 384]) : undefined}
+                sizes="(max-width:520px) 23vw, 96px"
+                alt={`${SLOT_LABEL[slot]}候选图`}
+                className="w-full h-full object-contain"
+                loading="lazy"
+              />
              <span
                className="pointer-events-none absolute inset-0 flex items-center justify-center opacity-0 group-hover:opacity-100"
                style={{ background: "color-mix(in srgb, var(--ink) 40%, transparent)", color: "#fff" }}
--- a/frontend/app/admin/settings/BrandSeoPanel.tsx
+++ b/frontend/app/admin/settings/BrandSeoPanel.tsx
@@ -1,26 +1,27 @@
 "use client";

-import { Check, ImagePlus, Images, Link2, X } from "lucide-react";
+import { Check, Crop, ImagePlus, Images, Link2, X } from "lucide-react";
 import { useEffect, useRef, useState, type Dispatch, type SetStateAction } from "react";
 import {
  AdminSegmented,
  AdminSettingsActions,
  AdminSettingsGroup,
 } from "@/components/admin";
+import BrandCropModal from "@/components/BrandCropModal";
 import BrandLockup from "@/components/BrandLockup";
 import { apiBrandFromMedia, apiUpdateSiteSettings, apiUploadBrand, type PublicSettings } from "@/lib/api";
 import {
-  BRAND_LOGO_FITS,
-  BRAND_LOGO_SIZES,
  brandAccept,
  brandAliasPath,
  brandFileOk,
+  normalizeBrandURL,
  type BrandLogoFit,
  type BrandLogoSize,
  type BrandMark,
  type BrandSlot,
 } from "@/lib/brand";
 import { toast } from "@/lib/toast";
+import { densitySrcSet, isOwnImage, pickVariantWidth, variantURL } from "@/lib/responsiveImage";
 import BrandMediaPicker from "./BrandMediaPicker";

 type SlotDraft = {
@@ -76,6 +77,9 @@ export default function BrandSeoPanel({
  const [saving, setSaving] = useState(false);
  const [saveError, setSaveError] = useState("");
  const [picker, setPicker] = useState<BrandSlot | null>(null);
+  const [cropSlot, setCropSlot] = useState<BrandSlot | null>(null);
+  const [cropSeedFile, setCropSeedFile] = useState<File | null>(null);
+  const [cropSeedUrl, setCropSeedUrl] = useState("");
  const [copiedSlot, setCopiedSlot] = useState<BrandSlot | null>(null);
  const blobs = useRef<string[]>([]);
  const saveGen = useRef(0);
@@ -122,6 +126,18 @@ export default function BrandSeoPanel({
    return draft.committed;
  };

+  const openCrop = (slot: BrandSlot, file: File | null, url: string) => {
+    setCropSlot(slot);
+    setCropSeedFile(file);
+    setCropSeedUrl(url);
+  };
+
+  const closeCrop = () => {
+    setCropSlot(null);
+    setCropSeedFile(null);
+    setCropSeedUrl("");
+  };
+
  const discard = () => {
    [light, dark, favicon].forEach((d) => {
      if (d.blob) URL.revokeObjectURL(d.blob);
@@ -233,8 +249,13 @@ export default function BrandSeoPanel({
      <div key={slot} className={`admin-brand-asset${compact ? " is-compact" : ""}`}>
        <div className={`admin-brand-swatch ${swatchClass}`}>
          {preview ? (
+            // 预览槽（≤56px 高，宽标可能更宽）：本站图走 160/384 密度变体
            // eslint-disable-next-line @next/next/no-img-element
-            <img src={preview} alt="" />
+            <img
+              src={isOwnImage(preview) ? variantURL(preview, pickVariantWidth(384)) : preview}
+              srcSet={isOwnImage(preview) ? densitySrcSet(preview, 384) : undefined}
+              alt=""
+            />
          ) : (
            <span>未设置</span>
          )}
@@ -271,7 +292,14 @@ export default function BrandSeoPanel({
                    toast(err);
                    return;
                  }
-                  replaceFile(slot, file);
+                  // SVG / ICO 无需裁剪，直接走原流程
+                  const isVector = file.name.toLowerCase().endsWith(".svg");
+                  const isIco = file.name.toLowerCase().endsWith(".ico");
+                  if (isVector || isIco) {
+                    replaceFile(slot, file);
+                    return;
+                  }
+                  openCrop(slot, file, "");
                }}
              />
            </label>
@@ -283,6 +311,17 @@ export default function BrandSeoPanel({
            >
              <Images size={14} /> 库
            </button>
+            {preview && !/\.(svg|ico)(\?.*)?$/i.test(preview) ? (
+              <button
+                type="button"
+                className="btn btn-line btn-sm"
+                disabled={saving}
+                title="调整画幅、铺法或重新裁剪"
+                onClick={() => openCrop(slot, null, preview)}
+              >
+                <Crop size={14} /> 调整
+              </button>
+            ) : null}
            <button
              type="button"
              className="admin-icon-btn"
@@ -331,7 +370,7 @@ export default function BrandSeoPanel({
              frame
              name={initial.site_name}
              wordmark={initial.site_wordmark}
-              slogan={initial.site_slogan}
+              slogan={initial.brand_slogan_visible ? initial.site_slogan : ""}
              logoLight={previewOf(light)}
              logoDark={previewOf(dark)}
            />
@@ -358,46 +397,9 @@ export default function BrandSeoPanel({
            />
          </div>
          {mark !== "text" ? (
-            <>
-              <div className="admin-brand-studio-field">
-                <span className="admin-brand-studio-kicker">比例</span>
-                <div className="admin-brand-size-row" role="group" aria-label="Logo 比例">
-                  {BRAND_LOGO_SIZES.map((item) => {
-                    const on = logoSize === item.id;
-                    return (
-                      <button
-                        key={item.id}
-                        type="button"
-                        className={`admin-brand-size-chip${on ? " is-on" : ""}`}
-                        onClick={() => {
-                          setLogoSize(item.id);
-                          if (saveError) setSaveError("");
-                        }}
-                      >
-                        <span className="admin-brand-size-chip-label">{item.label}</span>
-                        <span className="admin-brand-size-chip-px">
-                          {item.w}×{item.h}
-                        </span>
-                      </button>
-                    );
-                  })}
-                </div>
-              </div>
-              <div className="admin-brand-studio-field">
-                <span className="admin-brand-studio-kicker">铺法</span>
-                <AdminSegmented
-                  role="group"
-                  size="sm"
-                  ariaLabel="适配方式"
-                  value={logoFit}
-                  onChange={(v) => {
-                    setLogoFit(v);
-                    if (saveError) setSaveError("");
-                  }}
-                  options={BRAND_LOGO_FITS.map((item) => ({ key: item.id, label: item.label }))}
-                />
-              </div>
-            </>
+            <p className="admin-brand-studio-field text-[11.5px] self-center mb-0.5" style={{ color: "var(--ink-3)" }}>
+              画幅与铺法在上传/调整图片的裁剪弹窗中设置
+            </p>
          ) : null}
        </div>

@@ -412,11 +414,60 @@ export default function BrandSeoPanel({
        onClose={() => setPicker(null)}
        onPick={(item) => {
          if (!picker) return;
-          const [prev, set] = drafts[picker];
-          if (prev.blob) URL.revokeObjectURL(prev.blob);
-          set({ ...prev, file: null, blob: "", mediaId: item.id, mediaUrl: item.url });
+          const slot = picker;
+          setPicker(null);
+          // 已是品牌目录的历史图（含裁剪产物）：直接引用，不再复制
+          const brandURL = normalizeBrandURL(slot, item.url);
+          if (brandURL) {
+            const [prev, set] = drafts[slot];
+            if (prev.blob) URL.revokeObjectURL(prev.blob);
+            set({ committed: brandURL, file: null, blob: "", mediaId: null, mediaUrl: "" });
+            return;
+          }
+          const lower = item.url.toLowerCase();
+          const isVector = lower.endsWith(".svg");
+          const isIco = lower.endsWith(".ico");
+          // SVG / ICO 不可裁剪，复制一份进品牌目录后引用
+          if ((isVector || isIco) && item.attachmentId != null) {
+            const [prev, set] = drafts[slot];
+            if (prev.blob) URL.revokeObjectURL(prev.blob);
+            set({ ...prev, file: null, blob: "", mediaId: item.attachmentId, mediaUrl: item.url });
+            return;
+          }
+          openCrop(slot, null, item.url);
        }}
      />
+      {cropSlot ? (
+        <BrandCropModal
+          open
+          slot={cropSlot}
+          seedFile={cropSeedFile}
+          seedUrl={cropSeedUrl}
+          logoSize={logoSize}
+          logoFit={logoFit}
+          onSizeChange={(s) => {
+            setLogoSize(s);
+            if (saveError) setSaveError("");
+          }}
+          onFitChange={(f) => {
+            setLogoFit(f);
+            if (saveError) setSaveError("");
+          }}
+          onClose={closeCrop}
+          onSeedConsumed={() => {
+            setCropSeedFile(null);
+            setCropSeedUrl("");
+          }}
+          onCropped={(url) => {
+            const [, set] = drafts[cropSlot];
+            set((prev) => {
+              if (prev.blob) URL.revokeObjectURL(prev.blob);
+              return { committed: url, file: null, blob: "", mediaId: null, mediaUrl: "" };
+            });
+            closeCrop();
+          }}
+        />
+      ) : null}
    </AdminSettingsGroup>
  );
 }
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
freefire	e7b0686947	chore: bump version to 0.2.10	2026-10-09 19:07:57 +08:00
freefire	da72843c70	feat: 代码片段功能与 Markdown 内嵌片段渲染、文档截图等	2026-10-09 18:53:38 +08:00
freefire	5598e1cbb7	chore: bump version to 0.2.9	2026-10-03 02:40:45 +08:00
freefire	46e0cdc0b3	feat: 媒体库 blob 去重存储与品牌/注册等前端调整新增： - blob_store 二进制去重存储 + blob_dedup 测试其它： - 后端 settings/auth/media_library/upload/operations 服务与 handler 调整 - 前端品牌（BrandLockup/BrandCropModal/BrandSeoPanel）、注册、媒体库、分析详情页、Header/SiteChrome 等更新	2026-10-03 02:38:11 +08:00
freefire	8cfdfcbbf0	chore: bump version to 0.2.8	2026-10-02 01:48:02 +08:00
freefire	11f2131e4b	fix: 书库阅读页/帖子详情页/SiteDocMasthead/TOC 等前端细节修复	2026-10-02 01:47:14 +08:00
freefire	7912b67ddc	chore: bump version to 0.2.7	2026-10-02 01:41:19 +08:00
freefire	99c0f0319d	feat: 品牌裁剪弹窗/Markdown 行内短代码与详情视频块等新增： - BrandCropModal 品牌图裁剪弹窗 + cropImage 工具 - Markdown 行内短代码（inlineShortcodes + remark 插件） - MdDetails 折叠块、MdVideo 视频块组件 - directiveBlocks/inlineShortcodes 测试其它： - 聊天后端（handler/service chat）调整 - Markdown 渲染链路、编辑器、全局样式与品牌相关面板更新	2026-10-02 01:40:06 +08:00
freefire	3e98052c16	chore: bump version to 0.2.6	2026-10-01 03:08:23 +08:00
freefire	ff2ab286fb	feat: 书库导入导出/图片变体/书籍搜索/小组件运行时等新增： - 书库导入导出（library_import/library_export）及测试 - 图片变体生成（image_variants）与响应式图片（responsiveImage） - 书籍搜索（bookSearch）+ BookSearch/LibrarySearchGrid 组件 - 小组件运行时（widgetRuntime）与静态检查（widgetLint） - 上传缓存中间件（upload_cache）与字体 CSS 提取脚本其它： - 后端 handlers/services 全量调整 - 前端页面、组件、库函数与配置更新	2026-10-01 03:06:05 +08:00
@@ -1 +1 @@
 .2.5
 .2.10