Expand description
SQLite-backed disposable index for cached scan and session data.
The index lives at <base>/index.db (WAL mode). It is a cache only —
git is the source of truth. Any open/migrate/integrity failure deletes the
db file (and its -wal/-shm siblings) and recreates it from scratch.
The program never panics or aborts on index failure.
Schema is set to user_version = 1 after the initial migration. Callers
in later tasks wire read/write logic on top of the tables created here.