Version 1.3.4: Enhanced WebSocket connection management

- Fixed ping frame parsing in wsssh.c to properly handle WebSocket ping frames
- Added automatic pong responses with correct payload echoing
- Implemented WebSocket reconnection logic for both wsssh.c and wsscp.c
- Added --interval option for configurable connection retry intervals
- Smart timing: 1-second WebSocket reconnections vs 30-second initial connection retries
- Improved connection resilience and automatic recovery from network interruptions
- Updated documentation and changelog for version 1.3.4