Update full-text search test to the narrowed field contract

Commit notes

The DB-backed suite (skipped locally without Postgres) still asserted the old search-every-column behavior: it expected q=173.5 to match a sample by BPM. The field narrowing was deliberate — numeric/internal columns made queries like "120" or "true" match analysis state, and tempo has dedicated min_bpm/max_bpm filters — so the test now asserts the text-field matches AND that numeric columns are excluded.

Co-Authored-By: Claude Fable 5 <[email redacted]> Claude-Session: [private session redacted]