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.Application/Common/Interfaces/IApplicationDbContext.cs

@@ -1,3 +1,5 @@
+using CMSMicroservice.Domain.Entities.Blog;
+using CMSMicroservice.Domain.Entities.Content;
 using CMSMicroservice.Domain.Entities.Payment;
 using CMSMicroservice.Domain.Entities.Order;
 using CMSMicroservice.Domain.Entities.DiscountShop;
@@ -66,6 +68,17 @@ public interface IApplicationDbContext
     DbSet<InventoryItem> InventoryItems { get; }
     DbSet<StockMovement> StockMovements { get; }
     
+    // ============= Blog =============
+    DbSet<BlogPost> BlogPosts { get; }
+    DbSet<BlogCategory> BlogCategories { get; }
+    DbSet<BlogPostCategory> BlogPostCategories { get; }
+    DbSet<BlogPostTag> BlogPostTags { get; }
+    DbSet<BlogPostImage> BlogPostImages { get; }
+    
+    // ============= Content Management =============
+    DbSet<SitePage> SitePages { get; }
+    DbSet<SitePageSection> SitePageSections { get; }
+    
     /// <summary>
     /// دسترسی به DatabaseFacade برای اجرای raw SQL و Stored Procedures
     /// </summary>

src/CMSMicroservice.Application/Common/Interfaces/IFileManagementService.cs

@@ -1,37 +0,0 @@
-namespace CMSMicroservice.Application.Common.Interfaces;
-
-/// <summary>
-/// Service for uploading files to FMS (File Management Service)
-/// </summary>
-public interface IFileManagementService
-{
-    /// <summary>
-    /// Uploads a file to FMS and returns the stored file path
-    /// </summary>
-    /// <param name="directory">Target directory path (e.g. "Images/Products")</param>
-    /// <param name="fileBytes">Raw file bytes</param>
-    /// <param name="mime">MIME type (e.g. "image/jpeg")</param>
-    /// <param name="fileName">Original file name</param>
-    /// <param name="cancellationToken">Cancellation token</param>
-    /// <returns>The stored file path returned by FMS, or null if upload failed</returns>
-    Task<string?> UploadFileAsync(string directory, byte[] fileBytes, string mime, string? fileName, CancellationToken cancellationToken = default);
-    
-    /// <summary>
-    /// Uploads an image to FMS with optimization (resize + compress)
-    /// Returns both main image path and thumbnail path
-    /// </summary>
-    /// <param name="directory">Target directory path (e.g. "Images/Products")</param>
-    /// <param name="fileBytes">Raw image bytes</param>
-    /// <param name="mime">MIME type (e.g. "image/jpeg")</param>
-    /// <param name="fileName">Original file name</param>
-    /// <param name="cancellationToken">Cancellation token</param>
-    /// <returns>Tuple of (mainImagePath, thumbnailPath), either can be null if upload failed</returns>
-    Task<(string? MainImagePath, string? ThumbnailPath)> UploadImageWithThumbnailAsync(
-        string directory, byte[] fileBytes, string mime, string? fileName, 
-        CancellationToken cancellationToken = default);
-
-    /// <summary>
-    /// Deletes a file from FMS by its ID
-    /// </summary>
-    Task<bool> DeleteFileAsync(long fileId, CancellationToken cancellationToken = default);
-}

src/CMSMicroservice.Application/Common/Interfaces/IPaymentGatewayService.cs

@@ -27,6 +27,24 @@ public interface IPaymentGatewayService
         string verificationToken, 
         CancellationToken cancellationToken = default);
     
+    /// <summary>
+    /// تأیید پرداخت با مبلغ — برای درگاه‌هایی مثل زرین‌پال که مبلغ را در Verify نیاز دارند
+    /// </summary>
+    /// <param name="refId">شماره مرجع تراکنش (Authority در زرین‌پال)</param>
+    /// <param name="verificationToken">توکن تأیید از درگاه (Status در زرین‌پال)</param>
+    /// <param name="amountInToman">مبلغ تراکنش به تومان</param>
+    /// <param name="cancellationToken"></param>
+    /// <returns>وضعیت نهایی تراکنش</returns>
+    Task<PaymentVerificationResult> VerifyPaymentAsync(
+        string refId, 
+        string verificationToken,
+        decimal amountInToman,
+        CancellationToken cancellationToken = default)
+    {
+        // پیش‌فرض: درگاه‌هایی که Amount نمی‌خواهند، از overload بدون amount استفاده کنند
+        return VerifyPaymentAsync(refId, verificationToken, cancellationToken);
+    }
+    
     /// <summary>
     /// واریز مبلغ به حساب کاربر (برداشت از کیف پول)
     /// </summary>