feat: 微服务架构拆分和前后端优化

后端:
- 拆分出 agent_service, runtime_service, trading_service, news_service
- Gateway 模块化拆分 (gateway_*.py)
- 添加 domains/ 领域层
- 新增 control_client, runtime_client
- 更新 start-dev.sh 支持 split 服务模式

前端:
- 完善 API 服务层 (newsApi, tradingApi)
- 更新 vite.config.js
- Explain 组件优化

测试:
- 添加多个服务 app 测试

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/README.md

@@ -1,7 +1,31 @@
-
 ## QuickStart
 ```bash
 cd frontend
 npm install
 npm run dev
-```
+```
+
+## Optional Direct Service Calls
+
+The frontend still works with the compatibility backend entrypoint by default.
+In the current test-stage setup, split services are the recommended default.
+Point the frontend directly at those standalone services:
+
+```bash
+VITE_CONTROL_API_BASE_URL=http://localhost:8000/api
+VITE_RUNTIME_API_BASE_URL=http://localhost:8003/api/runtime
+VITE_NEWS_SERVICE_URL=http://localhost:8002
+VITE_TRADING_SERVICE_URL=http://localhost:8001
+```
+
+Current direct-call coverage:
+
+- runtime panel + gateway port discovery
+- `story`
+- `similar days`
+- `range explain`
+- `news for date`
+- `news categories`
+
+If these variables are not set, the frontend falls back to the existing
+WebSocket-driven compatibility flow.