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

frontend/components/PostRow.tsx

@@ -1,5 +1,5 @@
 import Link from "next/link";
-import { ArrowLeft } from "lucide-react";
+import { ArrowLeft, Pin, Star } from "lucide-react";
 import type { PostListItem } from "@/lib/api";
 import { formatRelative } from "@/lib/format";
 import { getPublicSettingsCached } from "@/lib/serverData";
@@ -44,6 +44,8 @@ export default async function PostRow({
   const pt = normalizePostType(post.post_type);
   const statusBadge = pt !== "discussion" ? typeStatusLabel(pt, post.type_status) : "";
   const statusClass = statusBadge ? typeStatusClass(pt, post.type_status) : "";
+  // 移动端徽章过多会挤占标题字数：仅隐藏「进行中」（开放式状态，详情页仍可见），终态徽章保留
+  const hideStatusOnMobile = statusBadge === "进行中";
   const authorName = post.user.nickname || post.user.username;
 
   return (
@@ -70,8 +72,16 @@ export default async function PostRow({
       <div className="flex-1 min-w-0">
         <div className="flex items-center gap-2 min-w-0">
           {/* 仅置顶/推荐在标题左侧 */}
-          {post.pinned > 0 && <span className="badge-pin shrink-0">置顶</span>}
-          {post.recommended && <span className="badge-rec shrink-0">推荐</span>}
+          {post.pinned > 0 && (
+            <span className="badge-pin shrink-0" title="置顶" aria-label="置顶">
+              <Pin size={12} fill="currentColor" strokeWidth={2.2} aria-hidden />
+            </span>
+          )}
+          {post.recommended && (
+            <span className="badge-rec shrink-0" title="推荐" aria-label="推荐">
+              <Star size={12} fill="currentColor" strokeWidth={2.2} aria-hidden />
+            </span>
+          )}
           <div className="min-w-0 flex items-center gap-2 flex-1 overflow-hidden">
             <Link
               href={postPath(urlStyle, post.id)}
@@ -88,7 +98,11 @@ export default async function PostRow({
               <span className="badge-type shrink-0">{postTypeLabel(post.post_type)}</span>
             )}
             {statusBadge && statusClass && (
-              <span className={`${statusClass} shrink-0`}>{statusBadge}</span>
+              <span
+                className={`${statusClass} shrink-0${hideStatusOnMobile ? " hidden sm:inline-flex" : ""}`}
+              >
+                {statusBadge}
+              </span>
             )}
           </div>
         </div>