feat(mcp_client): Implement ExternalMCPManager and StdioMCPServer with tests

scripts/mock_mcp_server.py

@@ -0,0 +1,47 @@
+import sys
+import json
+
+def main():
+    while True:
+        line = sys.stdin.readline()
+        if not line:
+            break
+        try:
+            req = json.loads(line)
+            method = req.get("method")
+            req_id = req.get("id")
+            
+            if method == "tools/list":
+                resp = {
+                    "jsonrpc": "2.0",
+                    "id": req_id,
+                    "result": {
+                        "tools": [
+                            {"name": "echo", "description": "Echo input", "inputSchema": {"type": "object"}}
+                        ]
+                    }
+                }
+            elif method == "tools/call":
+                name = req["params"].get("name")
+                args = req["params"].get("arguments", {})
+                if name == "echo":
+                    resp = {
+                        "jsonrpc": "2.0",
+                        "id": req_id,
+                        "result": {
+                            "content": [{"type": "text", "text": f"ECHO: {args}"}]
+                        }
+                    }
+                else:
+                    resp = {"jsonrpc": "2.0", "id": req_id, "error": {"message": "Unknown tool"}}
+            else:
+                resp = {"jsonrpc": "2.0", "id": req_id, "error": {"message": "Unknown method"}}
+            
+            sys.stdout.write(json.dumps(resp) + "\n")
+            sys.stdout.flush()
+        except Exception as e:
+            sys.stderr.write(f"Error: {e}\n")
+            sys.stderr.flush()
+
+if __name__ == "__main__":
+    main()