refactor(P2/P3): 完成全部7批重构 — 模块化、SSE退避、无障碍、Zod校验、Server组件、Room关系化

批次A：重命名 + 路由拆分
- store.ts → roomRepository.ts，更新全部 import
- blindbox/plan/route.ts 精简为薄路由，业务逻辑抽取到 planActions.ts / planQueries.ts

批次B：blindboxPlanGen.ts 拆分（710行 → src/lib/plan/）
- agentPlan.ts：Agent 工具调用与系统提示
- legacyPlan.ts：非 Agent 备用生成逻辑
- ideaSelection.ts：Idea 筛选与 Slot 映射
- transitEnrichment.ts：交通信息查询与填充
- index.ts：runPlanGeneration 主入口

批次C：SSE 连接稳定性
- useRoomPolling.ts 加入指数退避重连（上限60s，含Jitter）
- plan/stream/route.ts 添加30s心跳 + abort信号清理

批次D：无障碍修复
- Modal：role=dialog、aria-modal、aria-labelledby
- AuthModal：aria-label关闭按钮、tablist/tab/aria-selected
- PlanItemEditModal、QrInviteModal：补全aria-label
- BlindboxPlan：图标按钮aria-label

批次E：Zod 引入
- src/lib/schemas/ai.ts：AI返回值 Schema（IdeaTagsSchema等5个）
- src/lib/schemas/requests.ts：请求体 Schema
- ai.ts 手工验证替换为 Zod safeParse

批次F：Server Components
- achievements/page.tsx → Server Component + AchievementsClient.tsx
- profile/page.tsx → Server Component + ProfileClient.tsx

批次G：Room 关系化模型
- prisma/schema.prisma：新增 RoomMember、RoomRestaurant、RoomLike、RoomSwipe 4张表
- migration：20260302010000_room_relational_model
- roomRepository.ts 完整重写（关系查询+应用锁）
- buildRoomStatus.ts 适配关系查询

测试：全部329个用例通过，修复68个因auth mock缺失导致的测试失败

prisma/migrations/20260302010000_room_relational_model/migration.sql

@@ -0,0 +1,69 @@
+-- Drop old Room table and recreate with new relational schema
+-- Room data is ephemeral (24h TTL), so no data migration needed.
+
+DROP TABLE IF EXISTS "Room";
+
+-- CreateTable
+CREATE TABLE "Room" (
+    "id" TEXT NOT NULL PRIMARY KEY,
+    "creatorId" TEXT NOT NULL DEFAULT '',
+    "scene" TEXT NOT NULL DEFAULT 'eat',
+    "locked" BOOLEAN NOT NULL DEFAULT false,
+    "match" TEXT,
+    "createdAt" DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "expiresAt" DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
+-- CreateIndex
+CREATE INDEX "Room_expiresAt_idx" ON "Room"("expiresAt");
+
+-- CreateTable
+CREATE TABLE "RoomMember" (
+    "id" TEXT NOT NULL PRIMARY KEY,
+    "roomId" TEXT NOT NULL,
+    "userId" TEXT NOT NULL,
+    "kicked" BOOLEAN NOT NULL DEFAULT false,
+    "joinedAt" DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    CONSTRAINT "RoomMember_roomId_fkey" FOREIGN KEY ("roomId") REFERENCES "Room" ("id") ON DELETE CASCADE ON UPDATE CASCADE
+);
+
+-- CreateIndex
+CREATE UNIQUE INDEX "RoomMember_roomId_userId_key" ON "RoomMember"("roomId", "userId");
+CREATE INDEX "RoomMember_roomId_idx" ON "RoomMember"("roomId");
+
+-- CreateTable
+CREATE TABLE "RoomRestaurant" (
+    "id" TEXT NOT NULL PRIMARY KEY,
+    "roomId" TEXT NOT NULL,
+    "restaurantData" TEXT NOT NULL,
+    CONSTRAINT "RoomRestaurant_roomId_fkey" FOREIGN KEY ("roomId") REFERENCES "Room" ("id") ON DELETE CASCADE ON UPDATE CASCADE
+);
+
+-- CreateIndex
+CREATE INDEX "RoomRestaurant_roomId_idx" ON "RoomRestaurant"("roomId");
+
+-- CreateTable
+CREATE TABLE "RoomLike" (
+    "id" TEXT NOT NULL PRIMARY KEY,
+    "roomId" TEXT NOT NULL,
+    "userId" TEXT NOT NULL,
+    "restaurantId" TEXT NOT NULL,
+    CONSTRAINT "RoomLike_roomId_fkey" FOREIGN KEY ("roomId") REFERENCES "Room" ("id") ON DELETE CASCADE ON UPDATE CASCADE
+);
+
+-- CreateIndex
+CREATE UNIQUE INDEX "RoomLike_roomId_userId_restaurantId_key" ON "RoomLike"("roomId", "userId", "restaurantId");
+CREATE INDEX "RoomLike_roomId_idx" ON "RoomLike"("roomId");
+
+-- CreateTable
+CREATE TABLE "RoomSwipe" (
+    "id" TEXT NOT NULL PRIMARY KEY,
+    "roomId" TEXT NOT NULL,
+    "userId" TEXT NOT NULL,
+    "count" INTEGER NOT NULL DEFAULT 0,
+    CONSTRAINT "RoomSwipe_roomId_fkey" FOREIGN KEY ("roomId") REFERENCES "Room" ("id") ON DELETE CASCADE ON UPDATE CASCADE
+);
+
+-- CreateIndex
+CREATE UNIQUE INDEX "RoomSwipe_roomId_userId_key" ON "RoomSwipe"("roomId", "userId");
+CREATE INDEX "RoomSwipe_roomId_idx" ON "RoomSwipe"("roomId");