feat: 全局用户头像徽章，所有页面右上角统一显示

- 新增 GlobalUserBadge 组件，固定在右上角，已登录显示头像+用户名，未登录显示登录按钮
- 通过 layout.tsx 全局挂载，仅在个人中心页隐藏
- userId.ts 登录/登出时派发 nowhatever_auth 事件，组件实时响应
- 移除各页面重复的用户指示器（首页、极速救场、周末契约大厅、个人中心顶栏退出按钮）
- TopNav 右侧留出空间避免与全局徽章重叠
- 头像徽章采用暗色主题风格（bg-surface/80）

src/components/GlobalUserBadge.tsx

@@ -0,0 +1,73 @@
+"use client";
+
+import { useState, useEffect, useCallback } from "react";
+import { useRouter, usePathname } from "next/navigation";
+import { motion } from "framer-motion";
+import { User } from "lucide-react";
+import { getCachedProfile } from "@/lib/userId";
+import AuthModal from "@/components/AuthModal";
+import type { UserProfile } from "@/types";
+
+const HIDDEN_PREFIXES = ["/profile"];
+
+export default function GlobalUserBadge() {
+  const router = useRouter();
+  const pathname = usePathname();
+  const [profile, setProfile] = useState<UserProfile | null>(null);
+  const [showAuth, setShowAuth] = useState(false);
+  const hidden = HIDDEN_PREFIXES.some((p) => pathname.startsWith(p));
+
+  useEffect(() => {
+    setProfile(getCachedProfile());
+  }, [pathname]);
+
+  useEffect(() => {
+    const handler = () => setProfile(getCachedProfile());
+    window.addEventListener("nowhatever_auth", handler);
+    return () => window.removeEventListener("nowhatever_auth", handler);
+  }, []);
+
+  const handleAuth = useCallback((p: UserProfile) => {
+    setProfile(p);
+    setShowAuth(false);
+  }, []);
+
+  if (hidden) return null;
+
+  return (
+    <>
+      <motion.div
+        className="fixed right-4 top-3 z-40"
+        initial={{ opacity: 0, scale: 0.9 }}
+        animate={{ opacity: 1, scale: 1 }}
+        transition={{ delay: 0.1, duration: 0.3 }}
+      >
+        {profile ? (
+          <button
+            onClick={() => router.push("/profile")}
+            className="flex h-8 items-center gap-1.5 rounded-full bg-surface/80 px-3 ring-1 ring-border/50 backdrop-blur-md transition-colors hover:bg-elevated active:opacity-80"
+          >
+            <span className="text-base leading-none">{profile.avatar}</span>
+            <span className="max-w-20 truncate text-xs font-semibold text-gray-300">
+              {profile.username}
+            </span>
+          </button>
+        ) : (
+          <button
+            onClick={() => setShowAuth(true)}
+            className="flex h-8 items-center gap-1.5 rounded-full bg-surface/80 px-3 text-xs font-medium text-muted ring-1 ring-border/50 backdrop-blur-md transition-colors hover:bg-elevated hover:text-gray-300"
+          >
+            <User size={13} />
+            登录
+          </button>
+        )}
+      </motion.div>
+
+      <AuthModal
+        open={showAuth}
+        onClose={() => setShowAuth(false)}
+        onAuth={handleAuth}
+      />
+    </>
+  );
+}

src/components/MatchResult.tsx

@@ -22,7 +22,13 @@ import {
   Heart,
   UserPlus,
 } from "lucide-react";
-import { Restaurant, MatchType, RunnerUp, SceneType, UserProfile } from "@/types";
+import {
+  Restaurant,
+  MatchType,
+  RunnerUp,
+  SceneType,
+  UserProfile,
+} from "@/types";
 import { fireCelebration, playChime } from "@/lib/celebrate";
 import { isRegistered } from "@/lib/userId";
 import ShareCardModal from "@/components/ShareCardModal";
@@ -237,11 +243,14 @@ export default function MatchResult({
     setShowShareCard(true);
   }, []);
 
-  const handleAuth = useCallback((profile: UserProfile) => {
-    setRegistered(true);
-    setShowAuth(false);
-    showToast(`欢迎，${profile.username}！记录已保存`);
-  }, [showToast]);
+  const handleAuth = useCallback(
+    (profile: UserProfile) => {
+      setRegistered(true);
+      setShowAuth(false);
+      showToast(`欢迎，${profile.username}！记录已保存`);
+    },
+    [showToast],
+  );
 
   const handleFavorite = useCallback(async () => {
     if (!registered || favorited || favLoading) return;
@@ -296,7 +305,12 @@ export default function MatchResult({
         <motion.div
           initial={{ scale: 0, rotate: -20 }}
           animate={{ scale: 1, rotate: 0 }}
-          transition={{ type: "spring", stiffness: 200, damping: 12, delay: 0.2 }}
+          transition={{
+            type: "spring",
+            stiffness: 200,
+            damping: 12,
+            delay: 0.2,
+          }}
         >
           {isUnanimous ? (
             <PartyPopper size={56} className="text-emerald-400" />
@@ -311,7 +325,7 @@ export default function MatchResult({
           animate={{ y: 0, opacity: 1 }}
           transition={{ delay: 0.35 }}
         >
-          {isSolo ? "帮你选好了！" : "就去这了！"}
+          {isSolo ? "帮你选好了" : "就去这了"}
         </motion.h1>
 
         <motion.p
@@ -352,7 +366,12 @@ export default function MatchResult({
           className="relative mt-6 w-full overflow-hidden rounded-2xl bg-surface shadow-2xl ring-1 ring-border"
           initial={{ y: 60, opacity: 0 }}
           animate={{ y: 0, opacity: 1 }}
-          transition={{ type: "spring", stiffness: 180, damping: 18, delay: 0.5 }}
+          transition={{
+            type: "spring",
+            stiffness: 180,
+            damping: 18,
+            delay: 0.5,
+          }}
         >
           {registered && (
             <motion.button
@@ -362,11 +381,18 @@ export default function MatchResult({
               whileTap={{ scale: 0.85 }}
               initial={{ scale: 0, opacity: 0 }}
               animate={{ scale: 1, opacity: 1 }}
-              transition={{ delay: 0.7, type: "spring", stiffness: 300, damping: 15 }}
+              transition={{
+                delay: 0.7,
+                type: "spring",
+                stiffness: 300,
+                damping: 15,
+              }}
             >
               <Heart
                 size={18}
-                className={favorited ? "fill-red-500 text-red-500" : "text-white"}
+                className={
+                  favorited ? "fill-red-500 text-red-500" : "text-white"
+                }
               />
             </motion.button>
           )}

src/components/TopNav.tsx

@@ -47,7 +47,7 @@ export default function TopNav({
 
   return (
     <>
-      <nav className="relative z-10 flex h-14 items-center justify-between px-4">
+      <nav className="relative z-10 flex h-14 items-center justify-between pl-4 pr-24">
         <div className="flex items-center gap-1.5">
           <button
             onClick={() => setShowQr(true)}