Major changes:
- SaveVideo now uses DynamicCombo to show codec-specific encoding options
- When selecting h264 or vp9, quality and speed inputs appear dynamically
- Each codec has unique ADVANCED options (shown in 'Show Advanced' section):
- h264: Profile (baseline/main/high), Tune (film/animation/grain/etc.)
- vp9: Row Multi-threading, Tile Columns
- Quality maps to CRF internally with codec-appropriate ranges
- Speed presets map to FFmpeg presets
New types:
- VideoSpeedPreset enum with user-friendly names
- quality_to_crf() helper function
This demonstrates both DynamicCombo (codec-specific inputs) and advanced
widgets (profile/tune/row_mt/tile_columns hidden by default).
Amp-Thread-ID: https://ampcode.com/threads/T-019bce44-e743-7349-8bad-d3027d456fb1
Co-authored-by: Amp <amp@ampcode.com>