修复 TypeScript 基线并补齐测试类型

src/app/api/blindbox/rooms/route.test.ts

@@ -36,9 +36,9 @@ describe("GET /api/blindbox/rooms", () => {
       },
     ] as never);
 
-    prismaMock.blindBoxIdea.groupBy.mockResolvedValue([
+    prismaMock.blindBoxIdea.groupBy = vi.fn().mockResolvedValue([
       { roomId: "bb-room-1", _count: 3 },
-    ] as never);
+    ]) as never;
 
     const req = createRequest("/api/blindbox/rooms");
     const res = await GET(req, mockCtx);