feat: 新增大量社区功能与基础组件，优化站点整体体验

- 新增事件总线式toast通知系统
- 新增头像、阅读进度、404/500错误页等基础组件
- 重构页脚、布局、分页、点赞按钮等现有组件
- 新增用户个人页、通知中心、帖子编辑/发布/置顶/推荐管理功能
- 优化登录注册页面样式与交互
- 修复路径类型文件引用，更新站点元信息与字体配置

frontend/components/PostActions.tsx

@@ -5,6 +5,7 @@ import { useRouter } from "next/navigation";
 import Link from "next/link";
 import { Pencil, Trash2, Pin, Star } from "lucide-react";
 import { apiMe, apiDeletePost, apiTogglePin, apiToggleRecommend, type User } from "@/lib/api";
+import { toast } from "@/lib/toast";
 
 interface PostActionsProps {
   postId: string;
@@ -19,7 +20,7 @@ export default function PostActions({ postId, authorId, pinned, recommended }: P
   const [deleting, setDeleting] = useState(false);
   const [isPinned, setIsPinned] = useState(pinned > 0);
   const [isRecommended, setIsRecommended] = useState(recommended);
-  const [acting, setActing] = useState("");
+  const [acting, setActing] = useState(false);
 
   useEffect(() => {
     apiMe()
@@ -27,7 +28,6 @@ export default function PostActions({ postId, authorId, pinned, recommended }: P
       .catch(() => setUser(null));
   }, []);
 
-  // 仅作者本人或管理员可编辑/删除；置顶/推荐仅管理员
   const canManage = user && (user.id === authorId || user.role === "admin");
   const isAdmin = user?.role === "admin";
   if (!canManage) return null;
@@ -39,78 +39,76 @@ export default function PostActions({ postId, authorId, pinned, recommended }: P
       const res = await apiDeletePost(postId);
       if (res.message) {
         router.push("/");
+        toast("帖子已删除", "ok");
       } else {
-        alert(res.error || "删除失败");
+        toast(res.error || "删除失败");
       }
+    } catch {
+      toast("网络错误，删除失败");
     } finally {
       setDeleting(false);
     }
   };
 
   const handlePin = async () => {
-    setActing("pin");
+    setActing(true);
     try {
       const res = await apiTogglePin(postId);
       setIsPinned(res.pinned > 0);
+      toast(res.pinned > 0 ? "已置顶" : "已取消置顶", "ok");
       router.refresh();
+    } catch {
+      toast("操作失败，请稍后重试");
     } finally {
-      setActing("");
+      setActing(false);
     }
   };
 
   const handleRecommend = async () => {
-    setActing("recommend");
+    setActing(true);
     try {
       const res = await apiToggleRecommend(postId);
       setIsRecommended(res.recommended);
+      toast(res.recommended ? "已设为推荐" : "已取消推荐", "ok");
       router.refresh();
+    } catch {
+      toast("操作失败，请稍后重试");
     } finally {
-      setActing("");
+      setActing(false);
     }
   };
 
   return (
-    <div className="flex items-center gap-2 flex-wrap justify-end">
+    <div className="flex items-center gap-1.5 flex-wrap">
       {isAdmin && (
         <>
           <button
             onClick={handlePin}
-            disabled={acting !== ""}
-            className="flex items-center gap-1 text-sm px-3 py-1.5 rounded-lg hover:opacity-80 disabled:opacity-50"
-            style={{
-              background: isPinned ? "var(--primary)" : "var(--bg-secondary)",
-              color: isPinned ? "white" : "var(--text)",
-            }}
+            disabled={acting}
+            className="btn btn-line btn-sm"
+            style={isPinned ? { borderColor: "var(--accent)", color: "var(--accent)" } : undefined}
           >
-            <Pin size={14} /> {isPinned ? "取消置顶" : "置顶"}
+            <Pin size={13} /> {isPinned ? "取消置顶" : "置顶"}
           </button>
           <button
             onClick={handleRecommend}
-            disabled={acting !== ""}
-            className="flex items-center gap-1 text-sm px-3 py-1.5 rounded-lg hover:opacity-80 disabled:opacity-50"
-            style={{
-              background: isRecommended ? "#e11d48" : "var(--bg-secondary)",
-              color: isRecommended ? "white" : "var(--text)",
-            }}
+            disabled={acting}
+            className="btn btn-line btn-sm"
+            style={
+              isRecommended
+                ? { borderColor: "var(--gold)", color: "var(--gold)", background: "var(--gold-soft)" }
+                : undefined
+            }
           >
-            <Star size={14} /> {isRecommended ? "取消推荐" : "推荐"}
+            <Star size={13} /> {isRecommended ? "取消推荐" : "推荐"}
           </button>
         </>
       )}
-      <Link
-        href={`/post/${postId}/edit`}
-        className="flex items-center gap-1 text-sm px-3 py-1.5 rounded-lg hover:opacity-80"
-        style={{ background: "var(--bg-secondary)", color: "var(--text)" }}
-      >
-        <Pencil size={14} /> 编辑
+      <Link href={`/post/${postId}/edit`} className="btn btn-line btn-sm">
+        <Pencil size={13} /> 编辑
       </Link>
-      <button
-        onClick={handleDelete}
-        disabled={deleting}
-        className="flex items-center gap-1 text-sm px-3 py-1.5 rounded-lg text-red-600 hover:bg-red-50 disabled:opacity-50"
-        style={{ background: "var(--bg-secondary)" }}
-      >
-        <Trash2 size={14} /> {deleting ? "删除中..." : "删除"}
+      <button onClick={handleDelete} disabled={deleting} className="btn btn-danger btn-sm">
+        <Trash2 size={13} /> {deleting ? "删除中..." : "删除"}
       </button>
     </div>
   );