2b69540ecc
Tags now normalize to Title Case + collapsed whitespace at the central
TagService.find_or_create (and rename) — so manual entry, the create API, and
anything routed through find_or_create produce the canonical form. The lookup is
case-insensitive, so a differently-cased entry finds the existing tag instead of
forking a case-variant duplicate ('hatsune miku' / 'HATSUNE MIKU' → one tag).
normalize_tag_name uses per-word capitalize (not str.title(), which mangles
apostrophes) and folds ALL-CAPS input. Existing tags keep their current casing
until touched — a retro-normalize maintenance pass (Title-Case + merge
case-collisions) is the follow-up to convert the back-catalog.
Test: create title-cases + collapses whitespace; case/whitespace variants dedupe
to one tag.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>