完善论坛配置与发帖体验：TipTap 富文本、图片上传、修订历史、Feed 排序与后台参数管理。

同步更新 README 与 ROADMAP，反映最新功能与开发状态。

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/package.json

@@ -32,9 +32,7 @@
     "diff": "^9.0.0",
     "dompurify": "^3.4.10",
     "lucide-react": "^1.18.0",
-    "marked": "^18.0.5",
     "postcss": "^8.5.15",
-    "react": "^18.3.1",
     "react-dom": "^18.3.1",
     "react-hook-form": "^7.79.0",
     "react-router-dom": "^6.28.0",