Step 3: Add admin API endpoints for pricing configuration

- Add PricingConfigResponse and PricingConfigUpdate schemas
- Create PricingService with validation logic
- Add GET and PUT endpoints in routes/pricing.py
- Add MANAGE_PRICING permission to admin role
- Register pricing router in main.py
- Add comprehensive API tests for permissions and validation

backend/schemas/__init__.py

@@ -44,6 +44,9 @@ from .price import (
     PriceResponse,
 )
 
+# Export pricing schemas
+from .pricing import PricingConfigResponse, PricingConfigUpdate
+
 # Export profile schemas
 from .profile import ProfileResponse, ProfileUpdate
 
@@ -73,6 +76,8 @@ __all__ = [
     "PaginatedResponse",
     "PriceHistoryResponse",
     "PriceResponse",
+    "PricingConfigResponse",
+    "PricingConfigUpdate",
     "ProfileResponse",
     "ProfileUpdate",
     "RecordT",