Fix web terminal issues: improve xterm.js configuration, fix PTY setup, and resolve output alignment

- Enhanced xterm.js terminal configuration with proper theme, cursor, and font settings
- Fixed PTY setup in wssshd.py for better subprocess connection
- Improved terminal output formatting and line ending handling
- Resolved terminal connection and data flow issues
- Added proper terminal size configuration (80x24)
- Simplified input handling for better SSH compatibility