de4ef6ae74
The fandom/chapter exclusions added in fb05c5e only touched find_unused_tags
(the preview SAMPLE). prune_unused_tags re-implemented the predicate inline for
the dry-run COUNT and the live DELETE with only the image_tag + series_page
checks — so the preview showed a safe list of names while the delete removed
every fandom (and chaptered series). Operator-flagged 2026-06-08: real data loss
— assigned fandoms deleted, their characters SET-NULLed.
Extract _unused_tag_conditions() as the single source of truth and use it for
the preview, the count, AND the delete, so they can never diverge again. Added a
prune-commit test asserting the LIVE delete spares a character's fandom and a
chaptered series.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>