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>

shared/client/control_client.py

@@ -0,0 +1,82 @@
+# -*- coding: utf-8 -*-
+"""Control-plane client for workspace, agent, and guard operations."""
+
+from __future__ import annotations
+
+import httpx
+
+
+class ControlPlaneClient:
+    """Async client for the agent control-plane API surface."""
+
+    def __init__(self, base_url: str = "http://localhost:8000/api"):
+        self.base_url = base_url.rstrip("/")
+        self._client: httpx.AsyncClient | None = None
+
+    async def __aenter__(self) -> "ControlPlaneClient":
+        self._client = httpx.AsyncClient(base_url=self.base_url, timeout=30.0)
+        return self
+
+    async def __aexit__(self, exc_type, exc_val, exc_tb) -> None:
+        if self._client:
+            await self._client.aclose()
+
+    async def list_workspaces(self) -> dict:
+        response = await self._client.get("/workspaces")
+        response.raise_for_status()
+        return response.json()
+
+    async def get_workspace(self, workspace_id: str) -> dict:
+        response = await self._client.get(f"/workspaces/{workspace_id}")
+        response.raise_for_status()
+        return response.json()
+
+    async def list_agents(self, workspace_id: str) -> dict:
+        response = await self._client.get(
+            f"/workspaces/{workspace_id}/agents",
+        )
+        response.raise_for_status()
+        return response.json()
+
+    async def get_agent(self, workspace_id: str, agent_id: str) -> dict:
+        response = await self._client.get(
+            f"/workspaces/{workspace_id}/agents/{agent_id}",
+        )
+        response.raise_for_status()
+        return response.json()
+
+    async def fetch_pending_approvals(self) -> dict:
+        response = await self._client.get("/guard/pending")
+        response.raise_for_status()
+        return response.json()
+
+    async def approve_pending_approval(
+        self,
+        approval_id: str,
+        *,
+        one_time: bool = True,
+        expires_in_minutes: int = 30,
+    ) -> dict:
+        response = await self._client.post(
+            "/guard/approve",
+            json={
+                "approval_id": approval_id,
+                "one_time": one_time,
+                "expires_in_minutes": expires_in_minutes,
+            },
+        )
+        response.raise_for_status()
+        return response.json()
+
+    async def deny_pending_approval(
+        self,
+        approval_id: str,
+        *,
+        reason: str = "Denied by client",
+    ) -> dict:
+        response = await self._client.post(
+            "/guard/deny",
+            json={"approval_id": approval_id, "reason": reason},
+        )
+        response.raise_for_status()
+        return response.json()