iOS Persistence

Emit compile-ready GRDB code. Never produce N+1 queries. Keep all database access in the Data layer.

Load Strategy

Always read references/persistence.md.

Execution Contract

1. Domain layer: repository protocol only — no GRDB imports.
2. Data layer: FetchableRecord + PersistableRecord records, repository implementation, DatabaseManager usage.
3. Migrations are append-only — never modify existing migration identifiers.
4. Aggregates must be computed in SQL (GROUP BY, SUM, COUNT) — never in Swift loops.
5. Use ValueObservation for list views that need live updates.
6. Validate with a targeted build after changes.

Sister Skills

• ios-architect — app/feature scaffolding, Domain/Data/Presentation layers
• ios-testing — Swift Testing, mock repositories, DI patterns
• ios-platform — networking, navigation, privacy, Foundation Models