Root cause fix for #1331, covered from both directions.
Extraction half: on a content-hash cache hit the new job's vocals_path points into the old job's directory (cache working as designed), and both extraction call sites — per-speaker and the default per-segment — then wrote the new job's clone references into that older directory too. Deleting the older history entry orphaned them: every single-segment regen silently rendered in the default voice, and a full re-dub "fixed" it only because prep re-extracts. Clones now land in the current job's own dir; the AST test sweeps every extraction call so a third copy inherits the rule.
Deletion half: existing users' jobs already carry cross-directory references, and vocals are shared by design — so deleting a dub now checks whether any other saved dub still references files in its directory. If so, the history row is removed (the entry disappears as asked) but the directory is kept, with the holder logged. Clear-all untouched. 13 tests across both halves.
Palash Debnath
df049e959f