<reusable-compact filename="DATABASE.md">
SQLite `books` persistence via `app.persistence.get_book_store()`:
- `BookStore.add(title, author) -> Book`
- `BookStore.list_ordered() -> list[Book]`
- `BookStore.remove(book_id) -> bool`
- Schema: `id`, required `title`, required `author`, `created_at`; insertion order follows ascending SQLite primary key.
- Initialization is idempotent and preserves rows.
- SQLite access remains encapsulated; connections are scoped to Flask application contexts.
- Empty titles/authors are rejected and never stored.
</reusable-compact>

RESULT: SUCCESS

FILES CHANGED:
- app/__init__.py
- app/persistence.py
- app/routes.py
- tests/test_persistence.py

SUMMARY:
Implemented SQLite book persistence with add, ordered listing, removal, validation, idempotent initialization, and context-scoped connections. Added coverage for all acceptance criteria and edge cases. `sh bin/test.sh`: 14 passed. Ruff checks passed.

BLOCKERS:
- None