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

src/lib/plan/index.ts

@@ -0,0 +1,115 @@
+/**
+ * Plan generation entry point.
+ * Tries the agent path first, falls back to legacy pipeline.
+ */
+
+import { prisma } from "@/lib/prisma";
+import { ApiError } from "@/lib/api";
+import { runAgentPlanGeneration } from "./agentPlan";
+import { runLegacyPlanGeneration, PLAN_PROGRESS_MESSAGES } from "./legacyPlan";
+import { enrichTransitInfo, type EnrichDay } from "./transitEnrichment";
+import type { TaggedIdea } from "./ideaSelection";
+
+export interface PlanGenAvailableTime {
+  date: string;
+  startHour: number;
+  endHour: number;
+}
+
+export interface PlanGenResult {
+  id: string;
+  days: { date: string; items: unknown[]; summary: string }[];
+  createdAt: string;
+}
+
+export async function runPlanGeneration(
+  roomId: string,
+  userId: string,
+  availableTime: PlanGenAvailableTime,
+  onProgress?: (message: string) => void,
+): Promise<PlanGenResult> {
+  // 1. Fetch room & ideas
+  const room = await prisma.blindBoxRoom.findUnique({ where: { id: roomId } });
+  if (!room) throw new ApiError("房间不存在", 404);
+  if (!room.lat || !room.lng) {
+    throw new ApiError("请先设置房间位置", 400);
+  }
+
+  onProgress?.(PLAN_PROGRESS_MESSAGES.analyzing);
+
+  const allIdeas = await prisma.blindBoxIdea.findMany({
+    where: { roomId, status: "in_pool", category: { not: null } },
+    select: {
+      id: true,
+      content: true,
+      category: true,
+      timeSlot: true,
+      estimatedMinutes: true,
+      searchQuery: true,
+      searchType: true,
+      costLevel: true,
+      intensity: true,
+      needsBooking: true,
+    },
+  });
+
+  const taggedIdeas: TaggedIdea[] = allIdeas.filter(
+    (i): i is TaggedIdea =>
+      !!i.category &&
+      !!i.timeSlot &&
+      !!i.searchQuery &&
+      !!i.searchType &&
+      typeof i.estimatedMinutes === "number",
+  );
+
+  if (taggedIdeas.length < 2) {
+    throw new ApiError("盒子里至少需要 2 个已标记的想法才能生成计划", 400);
+  }
+
+  // 2. Try agent path, fallback to legacy
+  let days: { date: string; items: unknown[]; summary: string }[];
+
+  try {
+    const agentResult = await runAgentPlanGeneration(
+      { lat: room.lat, lng: room.lng, city: room.city ?? "" },
+      taggedIdeas,
+      availableTime,
+      onProgress,
+    );
+    days = agentResult.days;
+  } catch (e) {
+    console.error("runAgentPlanGeneration failed, falling back to legacy:", e);
+    onProgress?.("使用备用方案规划...");
+    const legacyResult = await runLegacyPlanGeneration(
+      { lat: room.lat, lng: room.lng },
+      taggedIdeas,
+      availableTime,
+      onProgress,
+    );
+    days = legacyResult.days;
+  }
+
+  // 3. Enrich transit info (best-effort)
+  onProgress?.("正在查询交通信息...");
+  await enrichTransitInfo(
+    days as EnrichDay[],
+    room.city ?? "上海",
+    room.lat,
+    room.lng,
+  );
+
+  // 4. Save to DB
+  const plan = await prisma.weekendPlan.create({
+    data: {
+      roomId,
+      userId,
+      planData: JSON.stringify({ days }),
+    },
+  });
+
+  return {
+    id: plan.id,
+    days,
+    createdAt: plan.createdAt.toISOString(),
+  };
+}