- db.test.ts (4 tests): IDB-primary path opens both stores + round-trips
saves and save_snapshots; localStorage-fallback path via vi.doMock('idb')
asserts LocalStorageDBAdapter is returned and tlg.saves.main is written
- snapshots.test.ts (4 tests): basic put + listSnapshots, empty store
returns [], CORE-08 5-then-3 retention with newest-first ordering, and
pruned entries are oldest by savedAt
- persist.test.ts (4 tests): all 4 navigator.storage scenarios per
CORE-05 + RESEARCH Pitfall 2 (granted true / false / throws / missing)
RED phase per TDD plan-level gate. Tests fail because db.ts / snapshots.ts /
persist.ts / db-localstorage-adapter.ts do not exist yet.
