- Use lowercase format names (subrip, webvtt, advancedsubstationalpha) to match SubtitleEdit 4.x CLI requirements
- Change /Convert to /convert for consistency with CLI docs
- Convert Path objects to strings explicitly for subprocess calls
- Respect conversion_method config in SDH stripping - skip SubtitleEdit when user has set pysubs2/pycaption/subby as their preferred method
- Add stderr suppression to SubtitleEdit calls