Re-processes *-temp.mp4 files from a backup location using season_info.py
to compute the correct target duration per clip (music_duration / DAYS_IN_MVT),
producing properly-sized *-final.mp4 files without touching the backup source.
Skips finals that already exist. Fixes drift caused by old pipeline sizing clips
to the wrong movement structure.
https://claude.ai/code/session_01C4jbd3waXG3eKZYbGUjLUQ
