feat: 用户名密码登录注册系统

- 新增 /api/auth/register 和 /api/auth/login 接口，使用 bcryptjs 哈希密码
- User 模型改为 username + passwordHash，id 自动生成 cuid
- 新增 AuthModal 组件（登录/注册双标签页），替换旧的 ProfileSetupModal
- 重写 /profile 页面：支持修改用户名、密码、头像、绑定邮箱、退出登录
- /api/user PUT 支持密码修改（需验证当前密码）和用户名唯一性校验
- 游客模式保留，右上角显示"登录"按钮；登录后显示头像和用户名
- 全局 nickname -> username 重命名（types、SwipeDeck、RoomManageModal、buildRoomStatus）
- 新增 logout() 清除登录态并重新生成游客 UUID

src/components/RestaurantCard.tsx

@@ -1,8 +1,9 @@
 "use client";
 
-import { useCallback } from "react";
-import { Star, MapPin, Clock, ExternalLink, Flame } from "lucide-react";
+import { useCallback, useState } from "react";
+import { Star, MapPin, Clock, ExternalLink, Flame, Bookmark } from "lucide-react";
 import { Restaurant } from "@/types";
+import { getUserId, isRegistered } from "@/lib/userId";
 
 interface RestaurantCardProps {
   restaurant: Restaurant;
@@ -14,6 +15,22 @@ function stopAll(e: React.SyntheticEvent) {
 }
 
 export default function RestaurantCard({ restaurant, likeCount = 0 }: RestaurantCardProps) {
+  const [favorited, setFavorited] = useState(false);
+
+  const handleFavorite = useCallback(async (e: React.MouseEvent | React.TouchEvent) => {
+    e.stopPropagation();
+    e.preventDefault();
+    if (favorited) return;
+
+    try {
+      const res = await fetch("/api/user/favorite", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({ userId: getUserId(), restaurant }),
+      });
+      if (res.ok) setFavorited(true);
+    } catch {}
+  }, [restaurant, favorited]);
   const openLink = useCallback(
     (url: string) => (e: React.MouseEvent | React.TouchEvent) => {
       e.stopPropagation();
@@ -59,6 +76,20 @@ export default function RestaurantCard({ restaurant, likeCount = 0 }: Restaurant
             {restaurant.name}
           </h2>
           <div className="mt-0.5 flex shrink-0 gap-1.5">
+            {isRegistered() && (
+              <button
+                onClick={handleFavorite}
+                onPointerDown={stopAll}
+                onTouchStart={stopAll}
+                className={`flex items-center justify-center rounded-full p-1 transition-colors ${
+                  favorited
+                    ? "bg-amber-100 text-amber-500"
+                    : "bg-zinc-50 text-zinc-400 active:bg-amber-50 active:text-amber-500"
+                }`}
+              >
+                <Bookmark size={13} className={favorited ? "fill-amber-400" : ""} />
+              </button>
+            )}
             <button
               onClick={openLink(amapUrl)}
               onPointerDown={stopAll}