sample_tfidf.json re-run over the corpus; set_finder_locate.json is the 35-bank
pass (was 19) after MAX_DF rose from 6 to 40 on the strength of 1/df weighting.

The npz hash DB (2.3 MB, rebuilds in 39 s) and the per-recording query profile
are ignored: they are caches keyed on inputs, not sources. Noting the tension
deliberately — 'generated + gitignored + never compared' is exactly what made
preload staleness debut at a venue — so both are produced by an explicit
subcommand and their inputs are versioned.