# Database Conventions

## Room
- DAO interfaces go in `database/daos/` package
- New DAOs must be registered as abstract functions in `AppDatabase`
- All DAO query functions must be `suspend` or return `Flow`
- Entity classes go in `database/` with `@Entity` annotation

## Repository Layer
- Every DAO is wrapped by a Repository in `source/` package
- Repositories are the only way screens/controllers access the database
- New repositories must be registered in `AppContainer` interface and `DefaultAppContainer`

## DataStore (Secrets)
- Cryptographic secrets (AES keys, HMAC keys, device ciphers) use **DataStore + Protobuf**, not Room
- Proto definitions are in `app/src/main/proto/` — do not modify without understanding migration implications
- User preferences (currency, settings) use DataStore Preferences

## Migrations
- Room version bumps require a `Migration` object registered in the database builder
- The `items.db` asset database must stay in sync with the Room schema