Fix GitHub MCP health check

platform/mcp/compose.yaml

@@ -183,7 +183,7 @@ services:
       GITHUB_READ_ONLY: "1"
     networks: [tools, egress]
     healthcheck:
-      test: ["CMD", "node", "-e", "const s=require('net').connect(8000,'127.0.0.1');s.setTimeout(2000);s.on('connect',()=>{s.end();process.exit(0)});s.on('error',()=>process.exit(1));s.on('timeout',()=>process.exit(1))"]
+      test: ["CMD", "python", "-c", "import socket; s=socket.create_connection(('127.0.0.1',8000),2); s.close()"]
       interval: 30s
       timeout: 5s
       retries: 5