refactor: Toast 升级为全局 Context，消除 onToast prop 透传

将 useToast 从独立 state hook 改为 Context-based，在 layout 中
挂载 ToastProvider 全局渲染 Toast。QrInviteModal、RoomManageModal、
ShareCardModal 不再需要 onToast prop，直接 useToast() 调用即可。
父组件 TopNav、MatchResult、profile、blindbox 移除了本地 Toast
渲染和 onToast 传递逻辑。

src/components/MatchResult.tsx

@@ -34,7 +34,6 @@ import { isRegistered } from "@/lib/userId";
 import ShareCardModal from "@/components/ShareCardModal";
 import RestaurantImage from "@/components/RestaurantImage";
 import AuthModal from "@/components/AuthModal";
-import Toast from "@/components/Toast";
 import { useToast } from "@/hooks/useToast";
 
 interface MatchResultProps {
@@ -632,10 +631,7 @@ export default function MatchResult({
           userCount,
           scene,
         }}
-        onToast={toast.show}
       />
-
-      <Toast message={toast.message} />
     </motion.div>
   );
 }

src/components/QrInviteModal.tsx

@@ -6,12 +6,12 @@ import { X, Copy, Share2, QrCode } from "lucide-react";
 import type { SceneType } from "@/types";
 import { getSceneConfig } from "@/lib/sceneConfig";
 import Modal from "@/components/Modal";
+import { useToast } from "@/hooks/useToast";
 
 interface QrInviteModalProps {
   open: boolean;
   onClose: () => void;
   roomId: string;
-  onToast: (msg: string) => void;
   scene?: SceneType;
 }
 
@@ -19,9 +19,9 @@ export default function QrInviteModal({
   open,
   onClose,
   roomId,
-  onToast,
   scene = "eat",
 }: QrInviteModalProps) {
+  const toast = useToast();
   const sceneConfig = getSceneConfig(scene);
   const inviteUrl =
     typeof window !== "undefined"
@@ -31,11 +31,11 @@ export default function QrInviteModal({
   const handleCopy = useCallback(async () => {
     try {
       await navigator.clipboard.writeText(inviteUrl);
-      onToast("邀请链接已复制，快去发给朋友吧！");
+      toast.show("邀请链接已复制，快去发给朋友吧！");
     } catch {
-      onToast("复制失败，请手动复制链接");
+      toast.show("复制失败，请手动复制链接");
     }
-  }, [inviteUrl, onToast]);
+  }, [inviteUrl, toast]);
 
   const handleShare = useCallback(async () => {
     const shareData = {

src/components/RoomManageModal.tsx

@@ -13,6 +13,7 @@ import {
 import { UserProfile } from "@/types";
 import { getAvatar, getAvatarBg } from "@/lib/avatars";
 import Modal from "@/components/Modal";
+import { useToast } from "@/hooks/useToast";
 
 interface RoomManageModalProps {
   open: boolean;
@@ -24,7 +25,6 @@ interface RoomManageModalProps {
   swipeCounts: Record<string, number>;
   totalCards: number;
   userProfiles: Record<string, UserProfile>;
-  onToast: (msg: string) => void;
 }
 
 export default function RoomManageModal({
@@ -37,8 +37,8 @@ export default function RoomManageModal({
   swipeCounts,
   totalCards,
   userProfiles,
-  onToast,
 }: RoomManageModalProps) {
+  const toast = useToast();
   const [loading, setLoading] = useState<string | null>(null);
   const [confirmKick, setConfirmKick] = useState<string | null>(null);
   const [confirmEnd, setConfirmEnd] = useState(false);
@@ -54,33 +54,33 @@ export default function RoomManageModal({
         });
         if (!res.ok) {
           const data = await res.json().catch(() => ({}));
-          onToast(data.error ?? "操作失败");
+          toast.show(data.error ?? "操作失败");
           return;
         }
         switch (action) {
           case "lock":
-            onToast("房间已锁定，其他人无法加入");
+            toast.show("房间已锁定，其他人无法加入");
             break;
           case "unlock":
-            onToast("房间已解锁");
+            toast.show("房间已解锁");
             break;
           case "kick":
-            onToast("已将该用户移出房间");
+            toast.show("已将该用户移出房间");
             setConfirmKick(null);
             break;
           case "end_voting":
-            onToast("已结束投票，正在结算结果");
+            toast.show("已结束投票，正在结算结果");
             setConfirmEnd(false);
             onClose();
             break;
         }
       } catch {
-        onToast("操作失败，请重试");
+        toast.show("操作失败，请重试");
       } finally {
         setLoading(null);
       }
     },
-    [roomId, userId, onToast, onClose],
+    [roomId, userId, toast, onClose],
   );
 
   const otherUsers = users.filter((u) => u !== userId);

src/components/ShareCardModal.tsx

@@ -6,6 +6,7 @@ import { X, Download, Share2, Loader2, Star, MapPin, Zap } from "lucide-react";
 import { QRCodeSVG } from "qrcode.react";
 import { toPng } from "html-to-image";
 import type { Restaurant, MatchType, SceneType } from "@/types";
+import { useToast } from "@/hooks/useToast";
 
 type ShareCardData =
   | {
@@ -28,7 +29,6 @@ interface ShareCardModalProps {
   open: boolean;
   onClose: () => void;
   data: ShareCardData;
-  onToast?: (msg: string) => void;
 }
 
 async function loadImageAsDataUrl(src: string): Promise<string | null> {
@@ -775,8 +775,8 @@ export default function ShareCardModal({
   open,
   onClose,
   data,
-  onToast,
 }: ShareCardModalProps) {
+  const toast = useToast();
   const cardRef = useRef<HTMLDivElement>(null);
   const backdropRef = useRef<HTMLDivElement>(null);
   const [generating, setGenerating] = useState(false);
@@ -821,7 +821,7 @@ export default function ShareCardModal({
   const handleSave = useCallback(async () => {
     const png = await handleGenerate();
     if (!png) {
-      onToast?.("生成图片失败，请重试");
+      toast.show("生成图片失败，请重试");
       return;
     }
     const name =
@@ -829,13 +829,13 @@ export default function ShareCardModal({
         ? `NoWhatever_${data.restaurant.name}.png`
         : `NoWhatever_周末契约.png`;
     downloadDataUrl(png, name);
-    onToast?.("图片已保存");
-  }, [handleGenerate, onToast, data]);
+    toast.show("图片已保存");
+  }, [handleGenerate, toast, data]);
 
   const handleShare = useCallback(async () => {
     const png = await handleGenerate();
     if (!png) {
-      onToast?.("生成图片失败，请重试");
+      toast.show("生成图片失败，请重试");
       return;
     }
 
@@ -852,8 +852,8 @@ export default function ShareCardModal({
     }
 
     downloadDataUrl(png, "NoWhatever.png");
-    onToast?.("图片已保存，快去分享吧！");
-  }, [handleGenerate, onToast]);
+    toast.show("图片已保存，快去分享吧！");
+  }, [handleGenerate, toast]);
 
   const handleBackdropClick = (e: React.MouseEvent) => {
     if (e.target === backdropRef.current) onClose();

src/components/ToastProvider.tsx

@@ -0,0 +1,29 @@
+"use client";
+
+import { useState, useCallback, useRef } from "react";
+import { ToastContext, type ToastPosition } from "@/hooks/useToast";
+import Toast from "./Toast";
+
+export default function ToastProvider({
+  children,
+}: {
+  children: React.ReactNode;
+}) {
+  const [message, setMessage] = useState("");
+  const [position, setPosition] = useState<ToastPosition>("top");
+  const timerRef = useRef<ReturnType<typeof setTimeout>>(undefined);
+
+  const show = useCallback((msg: string, pos: ToastPosition = "top") => {
+    clearTimeout(timerRef.current);
+    setMessage(msg);
+    setPosition(pos);
+    timerRef.current = setTimeout(() => setMessage(""), 2200);
+  }, []);
+
+  return (
+    <ToastContext.Provider value={{ show }}>
+      {children}
+      <Toast message={message} position={position} />
+    </ToastContext.Provider>
+  );
+}

src/components/TopNav.tsx

@@ -4,10 +4,8 @@ import { useState } from "react";
 import { QrCode, LogOut, Crown, Lock } from "lucide-react";
 import QrInviteModal from "./QrInviteModal";
 import RoomManageModal from "./RoomManageModal";
-import Toast from "@/components/Toast";
 import type { UserProfile, SceneType } from "@/types";
 import { getSceneConfig } from "@/lib/sceneConfig";
-import { useToast } from "@/hooks/useToast";
 
 interface TopNavProps {
   roomId: string;
@@ -37,7 +35,6 @@ export default function TopNav({
   scene = "eat",
 }: TopNavProps) {
   const sceneConfig = getSceneConfig(scene);
-  const toast = useToast();
   const [showQr, setShowQr] = useState(false);
   const [showManage, setShowManage] = useState(false);
 
@@ -79,13 +76,10 @@ export default function TopNav({
         </h1>
       </nav>
 
-      <Toast message={toast.message} />
-
       <QrInviteModal
         open={showQr}
         onClose={() => setShowQr(false)}
         roomId={roomId}
-        onToast={toast.show}
         scene={scene}
       />
 
@@ -100,7 +94,6 @@ export default function TopNav({
           swipeCounts={swipeCounts}
           totalCards={totalCards}
           userProfiles={userProfiles}
-          onToast={toast.show}
         />
       )}
     </>