- Increment catalog version from 4 to 5 and database version from 8 to 9
- Add `variants` field to `CatalogItemEntity`, `ItemSeed`, and `CatalogItem` models
- Populate variants for common items (apples, tomatoes, carrots, peppers, onions, potatoes, mushrooms, milk, yogurt, eggs, cheese, chicken, sausages, salmon, bread, grapes, peppers)
- Implement `ItemDetailPanel` composable with quantity