Release v1.6.0: Add youtube-downloader skill

- Add youtube-downloader v1.0.0
- Update marketplace to v1.6.0
- Comprehensive YouTube video/audio downloading with yt-dlp
- Android client workaround for nsig extraction issues
- Audio-only MP3 conversion
- Format selection and network error handling
- Demo GIF and comprehensive documentation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

demos/youtube-downloader/download-video.tape

@@ -0,0 +1,39 @@
+Output demos/youtube-downloader/download-video.gif
+
+Set FontSize 16
+Set Width 1400
+Set Height 700
+Set Theme "Dracula"
+Set Padding 20
+
+Type "# YouTube Downloader Demo" Sleep 500ms
+Enter
+Sleep 1s
+
+Type "# Show help for download_video.py" Sleep 500ms
+Enter
+Sleep 1s
+
+Type "./youtube-downloader/scripts/download_video.py --help" Sleep 500ms
+Enter
+Sleep 2s
+
+Type "# Example: Download audio only" Sleep 500ms
+Enter
+Sleep 1s
+
+Type "./youtube-downloader/scripts/download_video.py 'URL' --audio-only" Sleep 500ms
+Enter
+Sleep 1s
+
+Type "# Example: List available formats" Sleep 500ms
+Enter
+Sleep 1s
+
+Type "./youtube-downloader/scripts/download_video.py 'URL' --list-formats" Sleep 500ms
+Enter
+Sleep 1s
+
+Type "# Download complete!" Sleep 500ms
+Enter
+Sleep 2s