fix: Windows compatibility issues

[Saganaki22]

Fix Windows compatibility issues: SIGHUP signal and winsound dependency

Issues Fixed

1. SIGHUP Signal Compatibility

Problem: The application crashes on Windows systems with an AttributeError when trying to register a handler for SIGHUP, which is a Unix/Linux-specific signal that doesn't exist on Windows.

Solution: Added a conditional check using hasattr(signal, 'SIGHUP') to only register the SIGHUP handler on systems where it's available.

2. winsound Dependency Issue

Problem: winsound is incorrectly listed in requirements.txt, causing installation failures on non-Windows systems with the error "ERROR: No matching distribution found for winsound".

Solution: Remove winsound from requirements.txt since it's part of Python's standard library on Windows and shouldn't be listed as an external dependency.

Changes

• Modified signal handling in start_chat() function to check for SIGHUP availability
• Added platform-specific check for SIGHUP signal
• Improved code comments for clarity
• Removed winsound from requirements.txt (standard library module on Windows)

Testing

• Tested on Windows: Application now starts without crashing
• Tested on Linux: All signal handlers work as expected
• Tested installation on both platforms without winsound dependency issue
• No functional changes to Unix/Linux behavior

Impact

• Fixes Windows compatibility issues
• Maintains existing functionality on Unix/Linux systems
• Makes the application truly cross-platform
• Resolves dependency installation problems on non-Windows systems