feat: 契约生命周期 + 到期通知 + 成就墙

- 扩展 WeekendPlan schema: 新增 endTime 字段与 userId 索引
- PATCH /api/blindbox/plan 支持 accept/complete/expire 操作，
  接受时自动计算契约结束时间
- GET /api/blindbox/plan 支持 mode 参数 (latest/pending/history)
- 房间页接受契约后自动返回想法池，顶部显示"契约进行中"指示器
- 契约到期时触发浏览器通知 + 页面加载时弹出完成确认弹窗
- 新增 /achievements 成就墙页面：统计数据 + 决策记录/契约记录双标签
- 首页和个人中心新增成就墙入口

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

@@ -18,6 +18,8 @@ import {
   MapPin,
   Calendar,
   Sparkles,
+  ClipboardCheck,
+  ChevronRight,
 } from "lucide-react";
 import confetti from "canvas-confetti";
 import { getCachedProfile, isRegistered } from "@/lib/userId";
@@ -27,6 +29,7 @@ import BlindboxMyIdeas, { type MyIdea } from "@/components/BlindboxMyIdeas";
 import BlindboxDrawnHistory, { type DrawnIdea } from "@/components/BlindboxDrawnHistory";
 import WeekendTimeSelector from "@/components/WeekendTimeSelector";
 import BlindboxPlan from "@/components/BlindboxPlan";
+import ContractCompletionModal, { type PendingContract } from "@/components/ContractCompletionModal";
 import { useToast } from "@/hooks/useToast";
 import { useShare } from "@/hooks/useShare";
 import { BlindboxRoomSkeleton } from "@/components/Skeleton";
@@ -76,6 +79,12 @@ export default function BlindboxRoomPage() {
   const [planAccepted, setPlanAccepted] = useState(false);
   const [generating, setGenerating] = useState(false);
   const [showPlanShareCard, setShowPlanShareCard] = useState(false);
+  const [activeContract, setActiveContract] = useState<{
+    id: string;
+    days: WeekendPlanData[];
+    endTime: string | null;
+  } | null>(null);
+  const [pendingContracts, setPendingContracts] = useState<PendingContract[]>([]);
 
   const boxControls = useAnimation();
   const inputRef = useRef<HTMLInputElement>(null);
@@ -141,14 +150,15 @@ export default function BlindboxRoomPage() {
     const p = getCachedProfile();
     if (!room || !p) return;
     try {
-      const res = await fetch(`/api/blindbox/plan?roomId=${room.id}&userId=${p.id}`);
+      const res = await fetch(`/api/blindbox/plan?mode=latest&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");
+        setActiveContract({
+          id: data.plan.id,
+          days: data.plan.days,
+          endTime: data.plan.endTime ?? null,
+        });
       }
     } catch { /* ignore */ }
   }, [room]);
@@ -160,6 +170,53 @@ export default function BlindboxRoomPage() {
     }
   }, [isMember, room, fetchIdeas, fetchAcceptedPlan]);
 
+  // Check for expired contracts on load
+  useEffect(() => {
+    const p = getCachedProfile();
+    if (!isMember || !p) return;
+    (async () => {
+      try {
+        const res = await fetch(`/api/blindbox/plan?mode=pending&userId=${p.id}`);
+        if (!res.ok) return;
+        const data = await res.json();
+        if (data.pending?.length) setPendingContracts(data.pending);
+      } catch { /* ignore */ }
+    })();
+  }, [isMember]);
+
+  // Browser notification timer for active contract
+  useEffect(() => {
+    if (!activeContract?.endTime) return;
+    const end = new Date(activeContract.endTime).getTime();
+    const now = Date.now();
+    const ms = end - now;
+    if (ms <= 0) return;
+
+    if (typeof Notification !== "undefined" && Notification.permission === "default") {
+      Notification.requestPermission();
+    }
+
+    const timer = setTimeout(() => {
+      if (typeof Notification !== "undefined" && Notification.permission === "granted") {
+        const n = new Notification("周末契约到期", {
+          body: "你的周末契约已结束，完成了吗？",
+          icon: "/icon-192x192.png",
+        });
+        n.onclick = () => { window.focus(); n.close(); };
+      }
+      // Refresh pending contracts
+      const p = getCachedProfile();
+      if (p) {
+        fetch(`/api/blindbox/plan?mode=pending&userId=${p.id}`)
+          .then((r) => r.json())
+          .then((d) => { if (d.pending?.length) setPendingContracts(d.pending); })
+          .catch(() => {});
+      }
+    }, ms);
+
+    return () => clearTimeout(timer);
+  }, [activeContract?.endTime]);
+
   useEffect(() => {
     if (isMember && inputRef.current) {
       const t = setTimeout(() => inputRef.current?.focus(), 300);
@@ -505,6 +562,28 @@ export default function BlindboxRoomPage() {
         </button>
       </div>
 
+      {/* Active contract indicator */}
+      {activeContract && phase !== "plan_reveal" && (
+        <motion.button
+          className="mt-3 flex w-full max-w-sm items-center gap-2 rounded-xl bg-purple-600/10 px-3 py-2 ring-1 ring-purple-500/20 transition-colors active:bg-purple-600/20"
+          initial={{ opacity: 0, y: -8 }}
+          animate={{ opacity: 1, y: 0 }}
+          onClick={() => {
+            setPlanId(activeContract.id);
+            setPlanDays(activeContract.days);
+            setPlanAccepted(true);
+            setPhase("plan_reveal");
+          }}
+        >
+          <ClipboardCheck size={14} className="shrink-0 text-purple-400" />
+          <span className="text-xs font-medium text-purple-300">契约进行中</span>
+          <span className="text-[10px] text-purple-400/50">
+            {activeContract.days.map((d) => d.date).join(" + ")}
+          </span>
+          <ChevronRight size={12} className="ml-auto text-purple-400/40" />
+        </motion.button>
+      )}
+
       {/* Invite panel */}
       <AnimatePresence>
         {showInvite && (
@@ -808,13 +887,26 @@ export default function BlindboxRoomPage() {
                     fireConfetti();
                     if (planId && profile) {
                       try {
-                        await fetch("/api/blindbox/plan", {
+                        const res = await fetch("/api/blindbox/plan", {
                           method: "PATCH",
                           headers: { "Content-Type": "application/json" },
-                          body: JSON.stringify({ planId, userId: profile.id }),
+                          body: JSON.stringify({ planId, userId: profile.id, action: "accept" }),
+                        });
+                        const data = await res.json();
+                        setActiveContract({
+                          id: planId,
+                          days: planDays,
+                          endTime: data.endTime ?? null,
                         });
                       } catch { /* best-effort */ }
                     }
+                    toast.show("契约已接受！");
+                    timersRef.current.push(setTimeout(() => {
+                      setPhase("pool");
+                      setPlanId(null);
+                      setPlanDays([]);
+                      setPlanAccepted(false);
+                    }, 1500));
                   }}
                   onRegenerate={() => {
                     setPhase("time_select");
@@ -914,6 +1006,18 @@ export default function BlindboxRoomPage() {
       )}
 
       <div className="h-8 shrink-0" />
+
+      {/* Contract expiration check modal */}
+      {pendingContracts.length > 0 && profile && (
+        <ContractCompletionModal
+          contracts={pendingContracts}
+          userId={profile.id}
+          onDone={() => {
+            setPendingContracts([]);
+            setActiveContract(null);
+          }}
+        />
+      )}
     </div>
   );
 }