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>

backend/tests/test_service_clients.py

@@ -0,0 +1,107 @@
+# -*- coding: utf-8 -*-
+"""Tests for split-aware shared service clients."""
+
+import pytest
+
+from shared.client.control_client import ControlPlaneClient
+from shared.client.runtime_client import RuntimeServiceClient
+
+
+class _DummyResponse:
+    def __init__(self, payload):
+        self._payload = payload
+
+    def raise_for_status(self):
+        return None
+
+    def json(self):
+        return self._payload
+
+
+class _DummyAsyncClient:
+    def __init__(self):
+        self.calls = []
+
+    async def get(self, path, params=None):
+        self.calls.append(("get", path, params))
+        return _DummyResponse({"path": path, "params": params})
+
+    async def post(self, path, json=None):
+        self.calls.append(("post", path, json))
+        return _DummyResponse({"path": path, "json": json})
+
+    async def put(self, path, json=None):
+        self.calls.append(("put", path, json))
+        return _DummyResponse({"path": path, "json": json})
+
+    async def aclose(self):
+        return None
+
+
+@pytest.mark.asyncio
+async def test_control_plane_client_hits_current_workspace_and_guard_routes():
+    client = ControlPlaneClient()
+    client._client = _DummyAsyncClient()
+
+    await client.list_workspaces()
+    await client.get_workspace("demo")
+    await client.list_agents("demo")
+    await client.get_agent("demo", "risk_manager")
+    await client.fetch_pending_approvals()
+    await client.approve_pending_approval("ap-1")
+    await client.deny_pending_approval("ap-2", reason="nope")
+
+    assert client._client.calls == [
+        ("get", "/workspaces", None),
+        ("get", "/workspaces/demo", None),
+        ("get", "/workspaces/demo/agents", None),
+        ("get", "/workspaces/demo/agents/risk_manager", None),
+        ("get", "/guard/pending", None),
+        (
+            "post",
+            "/guard/approve",
+            {
+                "approval_id": "ap-1",
+                "one_time": True,
+                "expires_in_minutes": 30,
+            },
+        ),
+        (
+            "post",
+            "/guard/deny",
+            {
+                "approval_id": "ap-2",
+                "reason": "nope",
+            },
+        ),
+    ]
+
+
+@pytest.mark.asyncio
+async def test_runtime_service_client_hits_current_runtime_routes():
+    client = RuntimeServiceClient()
+    client._client = _DummyAsyncClient()
+
+    await client.fetch_context()
+    await client.fetch_agents()
+    await client.fetch_events()
+    await client.fetch_gateway_port()
+    await client.start_runtime({"tickers": ["AAPL"]})
+    await client.stop_runtime(force=True)
+    await client.restart_runtime({"tickers": ["MSFT"]})
+    await client.fetch_current_runtime()
+    await client.get_runtime_config()
+    await client.update_runtime_config({"schedule_mode": "intraday"})
+
+    assert client._client.calls == [
+        ("get", "/context", None),
+        ("get", "/agents", None),
+        ("get", "/events", None),
+        ("get", "/gateway/port", None),
+        ("post", "/start", {"tickers": ["AAPL"]}),
+        ("post", "/stop?force=true", None),
+        ("post", "/restart", {"tickers": ["MSFT"]}),
+        ("get", "/current", None),
+        ("get", "/config", None),
+        ("put", "/config", {"schedule_mode": "intraday"}),
+    ]