feat: implement product search, media library, and vendor customers

- Add full-text product search in ProductService.search_products()
  searching titles, descriptions, SKUs, brands, and GTINs
- Implement complete vendor media library with file uploads,
  thumbnails, folders, and product associations
- Implement vendor customers API with listing, details, orders,
  statistics, and status management
- Add shop search results UI with pagination and add-to-cart
- Add vendor media library UI with drag-drop upload and grid view
- Add database migration for media_files and product_media tables
- Update TODO file with current launch status (~95% complete)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

models/database/__init__.py

@@ -51,6 +51,7 @@ from .marketplace_product import (
     MarketplaceProduct,
     ProductType,
 )
+from .media import MediaFile, ProductMedia
 from .marketplace_product_translation import MarketplaceProductTranslation
 from .onboarding import OnboardingStatus, OnboardingStep, VendorOnboarding
 from .order import Order, OrderItem
@@ -138,6 +139,9 @@ __all__ = [
     "Inventory",
     "InventoryTransaction",
     "TransactionType",
+    # Media
+    "MediaFile",
+    "ProductMedia",
     # Invoicing
     "Invoice",
     "InvoiceStatus",