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/LikeButton.tsx

@@ -1,8 +1,10 @@
 "use client";
 
 import { useState } from "react";
-import { Heart } from "lucide-react";
+import { useRouter, usePathname } from "next/navigation";
+import { IconHeart } from "./Icons";
 import { apiToggleLike } from "@/lib/api";
+import { toast } from "@/lib/toast";
 
 interface LikeButtonProps {
   postId: string;
@@ -11,7 +13,14 @@ interface LikeButtonProps {
   variant?: "default" | "compact";
 }
 
-export default function LikeButton({ postId, liked: initialLiked, likeCount: initialCount, variant = "default" }: LikeButtonProps) {
+export default function LikeButton({
+  postId,
+  liked: initialLiked,
+  likeCount: initialCount,
+  variant = "default",
+}: LikeButtonProps) {
+  const router = useRouter();
+  const pathname = usePathname();
   const [liked, setLiked] = useState(initialLiked);
   const [count, setCount] = useState(initialCount);
   const [loading, setLoading] = useState(false);
@@ -19,36 +28,52 @@ export default function LikeButton({ postId, liked: initialLiked, likeCount: ini
   const handleClick = async () => {
     if (loading) return;
     setLoading(true);
+    // 乐观更新：先给反馈，失败再回滚
+    const wasLiked = liked;
+    setLiked(!wasLiked);
+    setCount((c) => c + (wasLiked ? -1 : 1));
     try {
       const res = await apiToggleLike(postId);
       if (res.error === "未登录") {
-        window.location.href = "/login";
+        router.push(`/login?redirect=${encodeURIComponent(pathname)}`);
         return;
       }
       if (typeof res.liked === "boolean") {
         setLiked(res.liked);
         setCount(res.like_count ?? count);
+      } else {
+        throw new Error(res.error || "FAIL");
       }
+    } catch {
+      setLiked(wasLiked);
+      setCount((c) => c + (wasLiked ? 1 : -1));
+      toast("操作失败，请稍后重试");
     } finally {
       setLoading(false);
     }
   };
 
-  const sizing = variant === "compact" ? "px-2 py-1 gap-1" : "px-3 py-1.5 gap-1.5";
-  const iconSize = variant === "compact" ? 14 : 16;
+  const compact =
+    variant === "compact"
+      ? "px-2.5 py-1.5 gap-1 text-[12.5px]"
+      : "px-4 py-2 gap-1.5 text-sm";
 
   return (
     <button
       onClick={handleClick}
       disabled={loading}
       title={liked ? "取消点赞" : "点赞"}
-      className={`flex items-center ${sizing} rounded-full text-sm font-medium transition-all disabled:opacity-50 ${
-        liked
-          ? "text-red-500 bg-red-50 dark:bg-red-900/20"
-          : "text-gray-500 hover:text-red-500 hover:bg-gray-100 dark:hover:bg-gray-800"
-      }`}
+      aria-pressed={liked}
+      className={`inline-flex items-center font-semibold tabular-nums rounded-full border transition-colors duration-150 hover:border-[var(--accent)] disabled:opacity-50 ${compact}`}
+      style={{
+        borderColor: liked ? "var(--accent)" : "var(--line-2)",
+        color: liked ? "var(--accent)" : "var(--ink-2)",
+        background: liked ? "var(--accent-soft)" : "var(--panel)",
+      }}
     >
-      <Heart size={iconSize} fill={liked ? "currentColor" : "none"} />
+      <span key={String(liked)} className={liked ? "j13-heart-pop inline-flex" : "inline-flex"}>
+        <IconHeart size={variant === "compact" ? 13 : 15} filled={liked} />
+      </span>
       <span>{count}</span>
     </button>
   );