- Removed UniversalMessageSender from group_generator.py and private_generator.py.
- Updated PlatformIOManager to manage legacy send drivers and ensure send pipeline readiness.
- Enhanced LegacyPlatformDriver to utilize prepared messages for sending.
- Refactored send_service to unify message sending logic and integrate with Platform IO.
- Added regression tests for Platform IO legacy driver and send service functionality.
add a shared port checker utility for availability and conflict detection
migrate WebUI, message server, and additional API server to use the new module
fail fast with clear error hints when a configured port is occupied (no auto-increment)
