Initial implementation of yt-dlp HLS proxy server

- Flask app with HLS proxy routes (/hls, /player, /)
- yt-dlp integration with 365-day in-memory cache
- URL validation with allowed domains (youtube, pornhub, etc)
- HTML5 HLS player with hls.js
- Unit tests: URL validation, cache, error handling
- Integration tests: ffmpeg-generated test video, full proxy chain
- Environment-based configuration (PORT, CACHE_TTL, LOG_LEVEL)
- MIT license

.gitignore

@@ -0,0 +1,11 @@
+__pycache__/
+*.py[cod]
+*$py.class
+*.so
+.Python
+.env
+.venv
+env/
+venv/
+*.log
+.DS_Store