test(05-01): add FTS5 search tests for database package
- seedSearchData helper creates full entity graph (7 tracks, 4 artists, 7 albums)
- Pure helper tests: tokeniseForFTS, buildFTSQuery, stripExtForSearch
- FTS5 search tests: basic term, empty query, special characters (AC/DC),
multi-word, diacritics (Beyonce→Beyoncé), ranking, filename search
- SearchFTSTracks verifies all 16 columns populated
- Index ops: insert, delete (documents contentless FTS5 limitation),
rebuild, clear (documents contentless limitation)
- Migration test: user_version >= 3, UNIQUE index enforcement
- 15 tests, all passing with -race
yonlu
dd34569ac0