Implemented with Repository Protocol pattern for offline fork support:
- CollectionService with PostgresCollectionRepository
- DeckService with PostgresDeckRepository
- DeckValidator with DeckConfig + CardService injection
- Starter deck definitions (5 types: grass, fire, water, psychic, lightning)
- Pydantic schemas for collection and deck APIs
- Unit tests for DeckValidator (32 tests passing)
Architecture follows pure dependency injection - no service locator patterns.
Added CLAUDE.md documenting DI requirements and patterns.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
