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/ClubMembershipCQ/Commands/AcceptClubMembershipContract/AcceptClubMembershipContractCommandHandler.cs

@@ -53,20 +53,28 @@ public class AcceptClubMembershipContractCommandHandler
         AcceptClubMembershipContractCommand request,
         CancellationToken cancellationToken)
     {
+        // خواندن UserId از JWT (امن‌تر از دریافت از کلاینت)
+        if (!long.TryParse(_currentUser.UserId, out var userId))
+            return new AcceptClubMembershipContractResponseDto
+            {
+                Success = false,
+                Message = "کاربر احراز هویت نشده است"
+            };
+
         _logger.LogInformation(
             "Processing club membership contract for UserId: {UserId}",
-            request.UserId
+            userId
         );
 
         // 1. دریافت کاربر
         var user = await _context.Users
             .Include(u => u.ClubMembership)
-            .FirstOrDefaultAsync(u => u.Id == request.UserId, cancellationToken);
+            .FirstOrDefaultAsync(u => u.Id == userId, cancellationToken);
 
         if (user == null)
         {
-            _logger.LogWarning("User not found: {UserId}", request.UserId);
-            throw new NotFoundException(nameof(User), request.UserId);
+            _logger.LogWarning("User not found: {UserId}", userId);
+            throw new NotFoundException(nameof(User), userId);
         }
 
         // 2. بررسی خرید پکیج

src/CMSMicroservice.Application/ClubMembershipCQ/Commands/AcceptClubMembershipContract/AcceptClubMembershipContractCommandValidator.cs

@@ -4,10 +4,6 @@ public class AcceptClubMembershipContractCommandValidator : AbstractValidator<Ac
 {
     public AcceptClubMembershipContractCommandValidator()
     {
-        RuleFor(x => x.UserId)
-            .GreaterThan(0)
-            .WithMessage("شناسه کاربر الزامی است");
-
         RuleFor(x => x.OtpCode)
             .NotEmpty()
             .WithMessage("کد تایید الزامی است")