Update CORS config; add architecture discussion comments

- Make CORS policy environment-aware: allow any origin in development, restrict to configured origins in production.
- Add detailed comments in CatalogService.cs and ICatalogRepository.cs discussing generic CRUD services, CQRS with MediatR, and repository interface placement, including both Copilot's and Hakan's perspectives.
- No functional changes to service or repository logic.

DbFirst.Application/Catalogs/CatalogService.cs

@@ -6,9 +6,33 @@ using DbFirst.Domain;
 namespace DbFirst.Application.Catalogs;
 
 //TODO: create generic service to reduce code duplication
-//TODO (TR): kod tekrar?n? azaltmak için generic bir servis/basit CRUD altyap?s? ekleyin
+
+/* Copilot's Response:
+A generic CRUD base service adds little value in your case:
+
+Pros:
+• Less boilerplate for simple entities without special logic.
+• Uniform CRUD signatures.
+
+Cons/Practical here:
+• Domain logic differs per entity(unique title check, setting audit fields, forbidding title changes, stored procs with output GUID).
+• Generic services tend to be diluted by virtual methods/hooks for special cases—ending up with per-entity overrides and little real gain.
+• With stored procedures and output parameters, the pattern doesn’t fit cleanly because operations aren’t symmetric (separate procs for insert/update/delete).
+
+Conclusion: For this solution a generic service would be more overhead than benefit. If you later have multiple very similar entities without special logic,
+you could consider a lightweight generic interface/base; for now, the specialized service implementation is cleaner. */
+
+/* Hakan's Response: 
+ * No, it absolutely makes sense to create a generic service using Options pattern. So, you can easily inject your SQL queries or stored procedure names via configuration.
+ * see: https://docs.microsoft.com/en-us/dotnet/core/extensions/options
+ */
+
 //TODO: implement CQRS pattern with MediatR
-//TODO (TR): CQRS desenini MediatR ile uygulay?n
+
+/* Hakan's response
+ * Here is the main part. We dont even need a service layer if we implement CQRS with MediatR at least for CRUD operations.
+ */
+
 public class CatalogService : ICatalogService
 {
     private readonly ICatalogRepository _repository;