feat(api): generate models for patched products, refunds, site configurations, payments, and user registration

- Added PatchedProduct, PatchedProductImage, PatchedRefund, and related models.
- Introduced Payment, PaymentBody, PaymentCreate, and PaymentRead models.
- Created enums for payment methods, reasons for refunds, roles, and shipping methods.
- Implemented models for site configurations and their opening hours.
- Added ZasilkovnaPacket and ZasilkovnaShipment models for handling shipping data.
- Generated user registration model with validation rules.
- Updated public API functions to support new models and queries.

frontend/Dockerfile.prod

@@ -6,6 +6,8 @@ COPY package*.json ./
 RUN npm ci || npm install
 COPY . .
 ENV NODE_ENV=production
+# Skip Orval - use pre-generated files committed to git
+ENV SKIP_ORVAL=true
 RUN npm run build
 
 # Step 2: Nginx runtime