The chunks FTS index is created once when the table is created, over zero
rows, and nothing folds later rows into it but an optimize. build_databases
bypasses populate_db, and with it the closing vacuum, so every database it
built had an index covering nothing.
Full-text search then returns near-arbitrary rows while still returning
results, so nothing looks wrong: measured FTS recall@5 of 0.0000 across 208
queries on a 40k pool, with hybrid losing 9.9pp to pure vector because the
dead branch still consumed half the fused slots.
Reachable outside the eval too, on any storage.auto_vacuum: false, which
every reference config sets. Reproduced through create_document alone:
five documents, five chunks, zero indexed rows.
Claude-Session: https://claude.ai/code/session_01WhudUtZm6qqiuv8Y1sbwSc
b46e8a4491