- Add AdminShopSummaryDto to AdminDtos.cs
- Add Shops list to AdminMerchantDetailDto (optional, with default null)
- Fetch shops in GetMerchantDetailQueryHandler with status + category name joins
- Tab "Cửa hàng" now shows real shop data (name, category, status, created date)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>