# S2: 后端 API — /api/dashboard 聚合查询

## 目标
在 app.py 中新增 `GET /api/dashboard`，聚合所有模块指标数据，返回 JSON。

## 涉及文件
- `app.py` (新增路由 `GET /api/dashboard`)
- `test_dashboard_api.py` (新建，API 集成测试)

## 数据流
circle.db (SQLite) + WeChat DB (SQLCipher) → Python 聚合 → JSON response

## 步骤
1. 写测试 (RED): test_dashboard_api.py → 验证返回结构
2. 实现路由 (GREEN): app.py → GET /api/dashboard
3. REFACTOR: 清理代码
4. VERIFY: pytest + smoketest

## JSON 结构
```json
{
  "chats": {groups, messages, speakers, shares},
  "articles": {total, summarized, unsummarized, learned, unlearned},
  "learn": {pending_review, approved, applied, rejected, unclassified, by_type: {skill, memory, todo, reference}},
  "reports": {daily, summaries, learn_records, images, last_generated},
  "jobs": {total, running, completed, failed, success_rate, last_completed},
  "auto_reply": {whitelist, pending, sent},
  "circle": {conversations, messages}
}
```

## 实现要点
- WeChat DB 查询用 try/except 包裹，失败返回 null
- 单个 DB 连接用完即关
- 响应时间目标 < 500ms
- 错误场景返回 500 + error 信息

## 验证命令
```bash
curl -s http://127.0.0.1:5000/api/dashboard | python3 -m json.tool | head -30
pytest test_dashboard_api.py -v
python3 test_smoke.py
```