#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