store parity (tai.py -> taicpp M3)

tai.py	taicpp	notes
Store (sqlite+FTS5, WAL)	detz::store::Store	sqlite3, WAL+NORMAL+timeout
ensure_schema/migrate_profiles	Store::migrate + schema_version	v1: records/chunks/logs
setup_fts + triggers	Store::setup_fts	fts_docs + ai/au/ad triggers
add/get/update/delete record	add_record/get_record/update_record/delete_record	parity
search (fts_docs MATCH)	Store::search	snippet col 4
add_chunks/chunk_lines	Store::add_chunks	single-chunk insert
spill_output/spilled_view/spill_or_truncate	same names	LIM 4000
DebugLog	detz::store::DebugLog	memory lines