feat: 新增帖子最后回复展示、文章目录与三栏布局，优化点赞按钮与导航栏

这是一次包含多个功能升级的提交：
1. 后端新增批量查询帖子最后回复的逻辑，在前端帖子列表项中展示最后回复信息
2. 重构点赞按钮，新增文章样式变体并统一样式逻辑
3. 重写工作台导航栏，精简默认展示的菜单选项
4. 新增文章目录组件，为帖子详情页添加文章目录导航
5. 重构帖子详情页，实现三栏响应式布局，新增板块卡片、作者信息栏与同板块热议推荐
6. 重构帖子列表行组件，优化排版与信息展示逻辑
7. 重构帖子管理操作组件，使用下拉菜单整合所有管理功能
8. 新增全局通用的滚动容器与点赞按钮样式

frontend/components/PostRow.tsx

@@ -1,19 +1,29 @@
 import Link from "next/link";
+import { ArrowLeft } from "lucide-react";
 import type { PostListItem } from "@/lib/api";
 import LikeButton from "./LikeButton";
 import Avatar from "./Avatar";
 import { IconComment, IconEye } from "./Icons";
 
-function formatTime(dateStr: string) {
-  const d = new Date(dateStr);
-  return `${d.getFullYear()}.${String(d.getMonth() + 1).padStart(2, "0")}.${String(
-    d.getDate()
-  ).padStart(2, "0")}`;
+/** 发帖/回复时间统一为相对时间：刚刚 / N分钟前 / N小时前 / N天前 / N个月前 / N年前 */
+function formatRelative(dateStr: string) {
+  const t = new Date(dateStr).getTime();
+  const diff = Date.now() - t;
+  const min = 60_000,
+    hour = 60 * min,
+    day = 24 * hour;
+  if (diff < min) return "刚刚";
+  if (diff < hour) return `${Math.floor(diff / min)}分钟前`;
+  if (diff < day) return `${Math.floor(diff / hour)}小时前`;
+  if (diff < 30 * day) return `${Math.floor(diff / day)}天前`;
+  if (diff < 365 * day) return `${Math.floor(diff / (30 * day))}个月前`;
+  return `${Math.floor(diff / (365 * day))}年前`;
 }
 
 /**
- * 帖子列表行：头像 + 标题 + 作者元信息 + 统计 + 点赞
- * 用于首页/板块页，以细线串联，悬浮浅色反馈
+ * 帖子列表行（参考社区信息流样式）：
+ * 大头像 + 加粗标题（徽章内联）+ 第二行「板块 · 作者 · 发布时间 ← 最后回复」+
+ * 右侧评论数等统计垂直居中。用于首页/板块页/搜索结果。
  */
 export default function PostRow({
   post,
@@ -30,13 +40,16 @@ export default function PostRow({
   showViews?: boolean;
   showLike?: boolean;
 }) {
+  const lastReply = post.last_reply;
+  const replied = lastReply && new Date(lastReply.created_at).getTime() > new Date(post.created_at).getTime() + 60_000;
+
   return (
     <div
-      className="group relative flex items-center gap-3 sm:gap-4 px-4 sm:px-5 border-t transition-colors hover:bg-[var(--panel-2)] j13-fade-up"
+      className="group relative flex items-center gap-3.5 sm:gap-4 px-4 sm:px-5 border-t transition-colors hover:bg-[var(--panel-2)] j13-fade-up"
       style={{
         borderColor: "var(--line)",
-        paddingTop: compact ? 13 : 16,
-        paddingBottom: compact ? 13 : 16,
+        paddingTop: compact ? 15 : 18,
+        paddingBottom: compact ? 15 : 18,
         animationDelay: `${Math.min(index, 9) * 35}ms`,
       }}
     >
@@ -46,57 +59,74 @@ export default function PostRow({
         aria-label={post.user.nickname}
         tabIndex={-1}
       >
-        <Avatar name={post.user.nickname || post.user.username} size={compact ? 38 : 42} />
+        <Avatar name={post.user.nickname || post.user.username} size={compact ? 44 : 46} />
       </Link>
 
       <div className="flex-1 min-w-0">
-        {(post.pinned > 0 || post.recommended) && (
-          <div className="flex items-center gap-1.5 mb-1.5 flex-wrap">
-            {post.pinned > 0 && <span className="badge-pin">置顶</span>}
-            {post.recommended && <span className="badge-rec">推荐</span>}
-          </div>
-        )}
-        <Link href={`/post/${post.id}`} className="stretch-link" aria-label={post.title}>
-          <h3
-            className="font-semibold text-[15px] sm:text-[16px] leading-snug truncate transition-colors group-hover:text-[var(--accent)]"
-            style={{ color: "var(--ink)" }}
+        <div className="flex items-center gap-2 min-w-0">
+          {post.pinned > 0 && <span className="badge-pin shrink-0">置顶</span>}
+          {post.recommended && <span className="badge-rec shrink-0">推荐</span>}
+          <Link
+            href={`/post/${post.id}`}
+            className="stretch-link min-w-0 flex-1"
+            aria-label={post.title}
           >
-            {post.title}
-          </h3>
-        </Link>
-        <div className="meta relative z-[2] flex items-center gap-2.5 mt-1.5 flex-wrap">
+            <h3
+              className="font-bold text-[16px] sm:text-[17px] leading-snug truncate transition-colors group-hover:text-[var(--accent)]"
+              style={{ color: "var(--ink)" }}
+            >
+              {post.title}
+            </h3>
+          </Link>
+        </div>
+        <div className="meta relative z-[2] flex items-center gap-x-2 gap-y-1 mt-1.5 flex-wrap text-[13px]">
+          {boardHref && (
+            <Link
+              href={`/board/${post.board.id}`}
+              className={`av-${post.board.id % 8} rounded-md px-1.5 py-px text-[11px] font-bold leading-[1.5] transition-opacity hover:opacity-85`}
+            >
+              {post.board.name}
+            </Link>
+          )}
           <Link
             href={`/u/${post.user.id}`}
-            className="hover:text-[var(--accent)] transition-colors"
+            className="font-semibold hover:text-[var(--accent)] transition-colors"
+            style={{ color: "var(--ink-2)" }}
           >
             {post.user.nickname}
           </Link>
-          {boardHref && (
-            <>
-              <span aria-hidden>·</span>
-              <Link
-                href={`/board/${post.board.id}`}
-                className="hover:text-[var(--accent)] transition-colors"
-              >
-                {post.board.name}
-              </Link>
-            </>
-          )}
           <span aria-hidden>·</span>
-          <span>{formatTime(post.created_at)}</span>
+          <span className="tabular-nums">{formatRelative(post.created_at)}</span>
+          {replied && (
+            <span className="inline-flex items-center gap-1 min-w-0">
+              <ArrowLeft size={13} className="shrink-0" aria-hidden />
+              <Link
+                href={`/u/${lastReply!.user.id}`}
+                className="font-medium hover:text-[var(--accent)] transition-colors truncate max-w-[8em]"
+              >
+                {lastReply!.user.nickname || lastReply!.user.username}
+              </Link>
+              <span className="tabular-nums shrink-0">{formatRelative(lastReply!.created_at)}</span>
+            </span>
+          )}
         </div>
       </div>
 
-      <div className="above-link flex items-center gap-2.5 sm:gap-3.5 shrink-0">
-        <span
-          className={`${showViews ? "hidden sm:inline-flex" : "inline-flex"} items-center gap-1.5 meta`}
+      <div className="above-link flex items-center gap-3 sm:gap-4 shrink-0">
+        <Link
+          href={`/post/${post.id}`}
+          tabIndex={-1}
           aria-label={`${post.comment_count} 条评论`}
+          className={`${showViews ? "hidden sm:inline-flex" : "inline-flex"} items-center gap-1.5 meta tabular-nums text-[13.5px] hover:text-[var(--accent)] transition-colors`}
         >
-          <IconComment size={15} />
+          <IconComment size={17} />
           {post.comment_count}
-        </span>
+        </Link>
         {showViews && (
-          <span className="hidden md:inline-flex items-center gap-1.5 meta" aria-label={`${post.view_count} 次浏览`}>
+          <span
+            className="hidden md:inline-flex items-center gap-1.5 meta tabular-nums"
+            aria-label={`${post.view_count} 次浏览`}
+          >
             <IconEye size={15} />
             {post.view_count}
           </span>