chore: 工具链升级到最新版本（Vite 8 / React 19 / react-router 8 / TS 7 / Go 1.26 依赖更新）

- 前端：vite ^8.2.2、react/react-dom ^19.2.8、react-router ^8.3.1（移除 react-router-dom）、typescript ^7.0.2、zustand ^5.0.15；适配升级带来的类型变化（react-hook-form Resolver、ProseMirror node.parent、tiptap focus 参数、timer undefined 等）
- 后端：升级 gin/jwt/minio-go/gorm/modernc-sqlite/x-crypto 等直接依赖至最新；gowebp v0.1.1 已是最新版本
- tsconfig 移除 baseUrl，paths 改为相对路径以兼容 TS7

frontend/src/pages/admin/AdminSettingsPage.tsx

@@ -294,24 +294,27 @@ export default function AdminSettingsPage() {
           }),
         );
         setAsideWidgets(loadedAsideWidgets);
-        const baseLimits: ForumLimits = {
-          open_posts_in_new_tab: true,
-          open_content_links_in_new_tab: true,
-          aside_show_tag_cloud: false,
-          aside_show_recent_comments: false,
-          aside_show_friend_links: true,
-          aside_show_showcase: false,
-          aside_widgets: loadedAsideWidgets,
-          nav_show_friend_links: true,
-          footer_show_friend_links: true,
-          nav_show_showcase: false,
-          footer_show_showcase: false,
-          feed_list_style: 'title',
-          feed_sort_tabs: normalizeFeedSortTabs(s.limits?.feed_sort_tabs ?? DEFAULT_FEED_SORT_TABS),
-          permalink_enabled: false,
-          permalink_ext: 'html',
-          ...s.limits,
-        };
+        // 默认值在前、server limits 覆盖在后（JSON 缺 key 不覆盖）
+        const baseLimits: ForumLimits = Object.assign(
+          {
+            open_posts_in_new_tab: true,
+            open_content_links_in_new_tab: true,
+            aside_show_tag_cloud: false,
+            aside_show_recent_comments: false,
+            aside_show_friend_links: true,
+            aside_show_showcase: false,
+            aside_widgets: loadedAsideWidgets,
+            nav_show_friend_links: true,
+            footer_show_friend_links: true,
+            nav_show_showcase: false,
+            footer_show_showcase: false,
+            feed_list_style: 'title',
+            feed_sort_tabs: normalizeFeedSortTabs(s.limits?.feed_sort_tabs ?? DEFAULT_FEED_SORT_TABS),
+            permalink_enabled: false,
+            permalink_ext: 'html',
+          } as ForumLimits,
+          s.limits,
+        );
         setLimits(mergeForumLimitsWithAsideWidgets(baseLimits, loadedAsideWidgets));
         setBranding({ ...DEFAULT_BRANDING, ...(s.branding ?? {}) });
         setMail({ ...EMPTY_MAIL, ...s.mail, password: '' });