feat(aiops): add mcp agent loop foundation

apps/api/src/plugins/mcp/registry.py

@@ -12,11 +12,65 @@ Provider 註冊中心，實現依賴注入 (DI) 模式：
 
 import structlog
 
-from src.plugins.mcp.interfaces import MCPToolProvider
+from src.plugins.mcp.interfaces import MCPTool, MCPToolProvider, MCPToolResult
 
 logger = structlog.get_logger(__name__)
 
 
+class AuditedMCPToolProvider(MCPToolProvider):
+    """Provider wrapper that writes every MCP tool call to the audit subsystem."""
+
+    def __init__(self, provider: MCPToolProvider) -> None:
+        self._provider = provider
+
+    @property
+    def name(self) -> str:
+        return self._provider.name
+
+    @property
+    def enabled(self) -> bool:
+        return self._provider.enabled
+
+    async def list_tools(self) -> list[MCPTool]:
+        return await self._provider.list_tools()
+
+    async def execute(
+        self,
+        tool_name: str,
+        parameters: dict,
+    ) -> MCPToolResult:
+        from src.services.mcp_audit_service import monotonic_ms, record_mcp_call
+
+        audit_context = parameters.get("_mcp_audit") if isinstance(parameters, dict) else None
+        provider_parameters = {
+            key: value for key, value in parameters.items()
+            if key != "_mcp_audit"
+        }
+        started = monotonic_ms()
+        result: MCPToolResult | None = None
+        try:
+            result = await self._provider.execute(tool_name, provider_parameters)
+            return result
+        finally:
+            duration_ms = monotonic_ms() - started
+            await record_mcp_call(
+                mcp_server=self.name,
+                tool_name=tool_name,
+                input_params=parameters,
+                output_result=result.output if result else None,
+                duration_ms=duration_ms,
+                success=bool(result.success) if result else False,
+                error_message=result.error if result else "provider_exception",
+                session_id=audit_context.get("session_id") if isinstance(audit_context, dict) else None,
+                flywheel_node=audit_context.get("flywheel_node") if isinstance(audit_context, dict) else None,
+                incident_id=audit_context.get("incident_id") if isinstance(audit_context, dict) else None,
+                agent_role=audit_context.get("agent_role") if isinstance(audit_context, dict) else None,
+            )
+
+    async def health_check(self) -> bool:
+        return await self._provider.health_check()
+
+
 class ProviderRegistry:
     """
     MCP Tool Provider 註冊中心
@@ -52,7 +106,7 @@ class ProviderRegistry:
         if provider.name in self._providers:
             raise ValueError(f"Provider '{provider.name}' already registered")
 
-        self._providers[provider.name] = provider
+        self._providers[provider.name] = AuditedMCPToolProvider(provider)
         logger.info(
             "provider_registered",
             name=provider.name,