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/MatchResult.tsx

@@ -22,6 +22,7 @@ import {
 } from "lucide-react";
 import { Restaurant, MatchType, RunnerUp } from "@/types";
 import { fireCelebration, playChime } from "@/lib/celebrate";
+import { isRegistered } from "@/lib/userId";
 
 interface MatchResultProps {
   restaurant: Restaurant;
@@ -30,6 +31,8 @@ interface MatchResultProps {
   runnerUps: RunnerUp[];
   allRestaurants: Restaurant[];
   userCount: number;
+  roomId: string;
+  userId: string;
   onReset: () => Promise<void>;
   onNarrow: (restaurantIds: string[]) => Promise<void>;
   resetting: boolean;
@@ -168,6 +171,8 @@ export default function MatchResult({
   runnerUps,
   allRestaurants,
   userCount,
+  roomId,
+  userId,
   onReset,
   onNarrow,
   resetting,
@@ -176,6 +181,7 @@ export default function MatchResult({
   const [showRunnerUps, setShowRunnerUps] = useState(false);
   const [toast, setToast] = useState("");
   const celebratedRef = useRef(false);
+  const historySavedRef = useRef(false);
   const isUnanimous = matchType === "unanimous";
 
   const showToast = useCallback((msg: string) => {
@@ -194,6 +200,25 @@ export default function MatchResult({
     }
   }, [isUnanimous]);
 
+  useEffect(() => {
+    if (historySavedRef.current) return;
+    if (!isRegistered()) return;
+    if (matchType === "no_match") return;
+
+    historySavedRef.current = true;
+    fetch("/api/user/history", {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify({
+        userId,
+        roomId,
+        restaurant,
+        matchType,
+        participants: userCount,
+      }),
+    }).catch(() => {});
+  }, [userId, roomId, restaurant, matchType, userCount]);
+
   const handleShare = useCallback(async () => {
     const lines = [
       isUnanimous