feat: 已接受契约持久化 — 保存/加载/自动展示

- PATCH /api/blindbox/plan: 接受契约时更新状态为 accepted
- GET /api/blindbox/plan: 查询房间内最近一次已接受的计划
- 进入房间时自动加载已接受计划并展示行程视图
- 修复整个周末想法不足时重复活动的问题（不足则只生成一天）

src/app/api/blindbox/plan/route.ts

@@ -190,16 +190,18 @@ export const POST = apiHandler(async (req) => {
         ]
       : [at];
 
-  // Select ideas per day, avoiding duplicates across days when possible
+  // Select ideas per day — skip extra days when ideas run out
   const dayIdeas: TaggedIdea[][] = [];
   const usedIds = new Set<string>();
   for (const dayConfig of dayConfigs) {
     const remaining = taggedIdeas.filter((i) => !usedIds.has(i.id));
-    const pool = remaining.length >= 2 ? remaining : taggedIdeas;
-    const selected = selectIdeasForSlots(pool, dayConfig.endHour - dayConfig.startHour);
+    if (remaining.length < 2) break;
+    const selected = selectIdeasForSlots(remaining, dayConfig.endHour - dayConfig.startHour);
     for (const idea of selected) usedIds.add(idea.id);
     dayIdeas.push(selected);
   }
+  // Trim to actual days generated (may be fewer than requested for "整个周末")
+  const actualDayConfigs = dayConfigs.slice(0, dayIdeas.length);
 
   const allSelected = dayIdeas.flat();
   if (allSelected.length === 0) {
@@ -260,7 +262,7 @@ export const POST = apiHandler(async (req) => {
 
   // Generate schedule for each day (parallel AI calls)
   const schedules = await Promise.all(
-    dayConfigs.map((dayConfig, idx) => {
+    actualDayConfigs.map((dayConfig, idx) => {
       const ideas = dayIdeas[idx];
       const ctx: ScheduleContext = {
         ideas: ideas.map((i) => ({
@@ -282,7 +284,7 @@ export const POST = apiHandler(async (req) => {
   const days = schedules
     .map((schedule, idx) =>
       schedule
-        ? { date: dayConfigs[idx].date, items: schedule.items, summary: schedule.summary }
+        ? { date: actualDayConfigs[idx].date, items: schedule.items, summary: schedule.summary }
         : null,
     )
     .filter((d) => d !== null);
@@ -308,3 +310,47 @@ export const POST = apiHandler(async (req) => {
     createdAt: plan.createdAt,
   });
 });
+
+export const PATCH = apiHandler(async (req) => {
+  const { planId, userId } = await req.json();
+  requireUserId(userId);
+  if (!planId) throw new ApiError("planId 不能为空");
+
+  const plan = await prisma.weekendPlan.findUnique({ where: { id: planId } });
+  if (!plan) throw new ApiError("计划不存在", 404);
+  if (plan.userId !== userId) throw new ApiError("只能接受自己的计划", 403);
+
+  await prisma.weekendPlan.update({
+    where: { id: planId },
+    data: { status: "accepted" },
+  });
+
+  return NextResponse.json({ ok: true });
+});
+
+export const GET = apiHandler(async (req) => {
+  const { searchParams } = new URL(req.url);
+  const roomId = searchParams.get("roomId");
+  const userId = searchParams.get("userId");
+
+  requireUserId(userId);
+  if (!roomId) throw new ApiError("roomId 不能为空");
+
+  const plan = await prisma.weekendPlan.findFirst({
+    where: { roomId, userId: userId!, status: "accepted" },
+    orderBy: { createdAt: "desc" },
+    select: { id: true, planData: true, createdAt: true },
+  });
+
+  if (!plan) return NextResponse.json({ plan: null });
+
+  const parsed = JSON.parse(plan.planData);
+
+  return NextResponse.json({
+    plan: {
+      id: plan.id,
+      days: parsed.days,
+      createdAt: plan.createdAt,
+    },
+  });
+});

src/app/blindbox/[code]/page.tsx

@@ -71,6 +71,7 @@ export default function BlindboxRoomPage() {
   const [confirmLeave, setConfirmLeave] = useState(false);
   const [leaving, setLeaving] = useState(false);
   const [locating, setLocating] = useState(false);
+  const [planId, setPlanId] = useState<string | null>(null);
   const [planDays, setPlanDays] = useState<WeekendPlanData[]>([]);
   const [planAccepted, setPlanAccepted] = useState(false);
   const [generating, setGenerating] = useState(false);
@@ -136,9 +137,28 @@ export default function BlindboxRoomPage() {
     } catch { /* ignore */ }
   }, [room]);
 
+  const fetchAcceptedPlan = useCallback(async () => {
+    const p = getCachedProfile();
+    if (!room || !p) return;
+    try {
+      const res = await fetch(`/api/blindbox/plan?roomId=${room.id}&userId=${p.id}`);
+      if (!res.ok) return;
+      const data = await res.json();
+      if (data.plan) {
+        setPlanId(data.plan.id);
+        setPlanDays(data.plan.days);
+        setPlanAccepted(true);
+        setPhase("plan_reveal");
+      }
+    } catch { /* ignore */ }
+  }, [room]);
+
   useEffect(() => {
-    if (isMember && room) fetchIdeas();
-  }, [isMember, room, fetchIdeas]);
+    if (isMember && room) {
+      fetchIdeas();
+      fetchAcceptedPlan();
+    }
+  }, [isMember, room, fetchIdeas, fetchAcceptedPlan]);
 
   useEffect(() => {
     if (isMember && inputRef.current) {
@@ -212,6 +232,7 @@ export default function BlindboxRoomPage() {
         throw new Error(data.error || "生成失败");
       }
       const data = await res.json();
+      setPlanId(data.id);
       setPlanDays(data.days);
       setPlanAccepted(false);
       setPhase("plan_reveal");
@@ -782,9 +803,18 @@ export default function BlindboxRoomPage() {
                   days={planDays}
                   accepted={planAccepted}
                   regenerating={generating}
-                  onAccept={() => {
+                  onAccept={async () => {
                     setPlanAccepted(true);
                     fireConfetti();
+                    if (planId && profile) {
+                      try {
+                        await fetch("/api/blindbox/plan", {
+                          method: "PATCH",
+                          headers: { "Content-Type": "application/json" },
+                          body: JSON.stringify({ planId, userId: profile.id }),
+                        });
+                      } catch { /* best-effort */ }
+                    }
                   }}
                   onRegenerate={() => {
                     setPhase("time_select");
@@ -792,6 +822,7 @@ export default function BlindboxRoomPage() {
                   onShare={() => setShowPlanShareCard(true)}
                   onBack={() => {
                     setPhase("pool");
+                    setPlanId(null);
                     setPlanDays([]);
                     setPlanAccepted(false);
                   }}