Fix: Windows Unicode encoding issue\

[vivche]

Fixes #644 - Windows Unicode Encoding Issue Report

Problem

The application crashes on Windows when processing or displaying Unicode characters beyond the Western European character set. This critical cross-platform compatibility issue occurs because:

• Windows Default: Python uses cp1252 encoding for stdout/stderr (limited to 256 Western European characters)
• Modern Web/Cloud: Azure services and web applications use UTF-8 encoding universally
• Result: Application crashes when logging or displaying emojis, international characters, IPA symbols, or special formatting

This affects multiple areas including:

• ✅ Video transcripts with phonetic symbols
• ✅ Chat messages containing emojis or international text
• ✅ Agent responses with Unicode formatting
• ✅ Debug logging across the entire application
• ✅ Error messages and stack traces

Common Error: UnicodeEncodeError: 'charmap' codec can't encode character '\uXXXX'

Solution

Configured UTF-8 encoding globally at application startup for Windows platforms. This ensures:

• Consistent encoding across all output streams
• Support for all Unicode characters (1.1M+ characters vs 256)
• Cross-platform compatibility (matches Linux/macOS behavior)

Changes

• Modified app.py to reconfigure sys.stdout and sys.stderr to UTF-8 on Windows
• Applied at top of file before any imports or print statements
• Includes fallback for older Python versions (<3.7)
• Platform-specific fix (only applies on Windows)

Testing

• ✅ Video processing with IPA phonetic symbols in transcripts
• ✅ Chat messages with emojis and international characters
• ✅ Debug logging with Unicode content
• ✅ Verified no impact on Linux/macOS deployments