Operator: sees 'December Holiday' but not 'Holiday' on its own as a
recommended tag.
Bigram supersession dropped a unigram when the UNION of all bigrams
containing it covered >=0.8 of its products. 'holiday' spans
'december holiday' + 'winter holiday' + 'christmas holiday' -> union
covered it -> 'holiday' hidden as redundant. Changed: supersede only
when a SINGLE bigram covers >=0.8 (a true fragment, e.g.
'write'->'write room'). An umbrella unigram covered only by the union
of DISTINCT bigrams is now KEPT as its own category.
Also answered operator Q in docs: the stem engine NEVER auto-applies
to new products — suggest-then-approve only (/s/{id}/tags button or
operator-run backfill_tags CLI). Adding a product does not
auto-categorize it.
Tests: test_suggest_clusters_multi_bigram_supersedes_unigram renamed
to ..._keeps_umbrella_unigram_over_multi_bigrams (behaviour
intentionally flipped per operator); +..._surfaces_holiday_with_phrase_bigrams;
single-dominant-bigram supersession test unchanged + still green.
1140 passed. Docs: mps-24.md Phase 2.8m.
russell@unturf.com
60a93de763
