Implement the schema foundation for syncing products from POD providers
like Printify. This includes encrypted credential storage, product/variant
schemas, and an Oban worker for background sync.
New modules:
- Vault: AES-256-GCM encryption for API keys
- Products context: CRUD and sync operations for products
- Provider behaviour: abstraction for POD provider implementations
- ProductSyncWorker: Oban job for async product sync
Schemas: ProviderConnection, Product, ProductImage, ProductVariant
Also reorganizes Printify client to lib/simpleshop_theme/clients/ and
mockup generator to lib/simpleshop_theme/mockups/ for better structure.
134 tests added covering all new functionality.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Jamey Greenwood
c5c06d9979