feat: integrate PYMS payment gateway, add blog/sitepage/image services, local file manager

Payment Gateway:
- Add PYMSPaymentService: IPaymentGatewayService via gRPC to PYMS microservice
- Add ZarinPalPaymentService: direct ZarinPal integration (backup)
- Register 'pyms' payment provider in DI ConfigureServices
- Add PYMS proto files (pyms_transaction.proto, pyms_public_messages.proto)
- Fix VerifyDiscountWalletCharge: pass 'OK' as status instead of Authority
- Update appsettings: PaymentProvider=pyms, sandbox mode, merchant ID

Blog System:
- Add BlogCategory, BlogPost, BlogPostImage entities and CQRS
- Add proto files and gRPC services for blog management
- Add Mapster profiles for blog responses

Content Management:
- Add SitePage entity and CQRS for static pages
- Add proto and gRPC service for site pages

Image/File Management:
- Add LocalFileManager with disk storage + base64 serving + FMS fallback
- Add ImagePathResolverInterceptor for gRPC responses
- Add ImageResolverService for explicit image resolution
- Add UploadsController for public file serving with FMS fallback
- Add PaymentCallbackController for discount order payment callbacks

Database:
- Add blog and content entity migrations
- Remove ImagePath MaxLength constraints
- Remove old FileManagementService (replaced by LocalFileManager)

src/CMSMicroservice.Infrastructure/ConfigureServices.cs

@@ -37,7 +37,8 @@ public static class ConfigureServices
         services.AddScoped<IAlertService, AlertService>();
         services.AddScoped<IUserNotificationService, UserNotificationService>();
         services.AddScoped<IKavenegarService, KavenegarService>();
-        services.AddScoped<IFileManagementService, FileManagementService>();
+        // Local file manager — files are saved to wwwroot/uploads/ on CMS disk
+        services.AddSingleton<CMSMicroservice.Application.Common.FileManager.IFileManager, LocalFileManager>();
         services.AddScoped<IPermissionService, PermissionService>();
         
         // Daya Loan API Service - قابل تغییر بین Mock و Real
@@ -73,19 +74,31 @@ public static class ConfigureServices
                 });
         }
         
-        // Payment Gateway Service - فقط Daya (درگاه اینترنتی از Gateway میاد نه CMS)
-        var useRealPaymentGateway = configuration.GetValue<bool>("UseRealPaymentGateway", false);
+        // Payment Gateway Service - Multi-Provider Architecture
+        // پشتیبانی از درگاه‌های مختلف: ZarinPal, Daya, PYMS, Mock
+        var paymentProvider = configuration.GetValue<string>("PaymentProvider", "Mock")?.ToLowerInvariant();
         
-        if (useRealPaymentGateway)
+        switch (paymentProvider)
         {
-            // فقط Daya برای پرداخت به کاربران (Payout)
-            services.AddHttpClient<IPaymentGatewayService, DayaPaymentService>()
-                .SetHandlerLifetime(TimeSpan.FromMinutes(5));
-        }
-        else
-        {
-            // Mock برای Development و Testing
-            services.AddScoped<IPaymentGatewayService, MockPaymentGatewayService>();
+            case "zarinpal":
+                services.AddHttpClient<IPaymentGatewayService, ZarinPalPaymentService>()
+                    .SetHandlerLifetime(TimeSpan.FromMinutes(5));
+                break;
+            
+            case "daya":
+                services.AddHttpClient<IPaymentGatewayService, DayaPaymentService>()
+                    .SetHandlerLifetime(TimeSpan.FromMinutes(5));
+                break;
+            
+            case "pyms":
+                // PYMS (Payment Microservice) — ارتباط gRPC با سرویس پرداخت مستقل
+                services.AddSingleton<IPaymentGatewayService, PYMSPaymentService>();
+                break;
+            
+            case "mock":
+            default:
+                services.AddScoped<IPaymentGatewayService, MockPaymentGatewayService>();
+                break;
         }
         
         services.AddScoped<IApplicationDbContext>(p => p.GetRequiredService<ApplicationDbContext>());