Add server ready state tracking for MCP service to prevent
"Received request before initialization was complete" errors
when clients connect before GNS3 server completes startup.
Changes:
- Add MCP server ready state management with wait/notify mechanism
- Modify auth wrapper to wait for server initialization before accepting connections
- Set MCP server ready flag after GNS3 startup completes
This ensures MCP protocol initialization handshake only occurs
after GNS3 server is fully initialized, preventing race
conditions during server startup.