Fixed new user username formating

PostFundManagement.Application/Handlers/ClientCredentialsTokenHandler.cs

@@ -40,8 +40,10 @@ public class ClientCredentialsTokenHandler(ILogger<ClientCredentialsTokenHandler
 
             if (!response.IsSuccessStatusCode)
             {
-                logger.LogWarning("HTTP request failed with status {StatusCode} for {Method} {RequestUri}",
-                    response.StatusCode, request.Method, request.RequestUri);
+                var content = await response.Content.ReadAsStringAsync(cancellationToken);
+                logger.LogWarning("HTTP request failed with status {StatusCode} for {Method} {RequestUri}. Details: {Details}",
+                    response.StatusCode, request.Method, request.RequestUri, content);
+
             }
 
             return response;

PostFundManagement.Application/Services/Users/UserService.cs

@@ -1,4 +1,4 @@
-using PostFundManagement.Application.Abstractions.Services;
+using PostFundManagement.Application.Abstractions.Services;
 using PostFundManagement.Application.Services.Shared;
 using PostFundManagement.Domain;
 using PostFundManagement.Domain.Abstractions;
@@ -147,10 +147,30 @@ public sealed class UserService(IDbContextFactory<ApplicationDbContext> contextF
             if (await context.Users.AnyAsync(u => u.Email == email, cancellationToken))
                 return Result.Fail(ValidationError.Create("User with this email already exists."));
 
+            // Normalize and sanitize request.UserName for ASP.NET Core Identity / Skoruba
+            // IdentityServer rejects user names containing whitespace or disallowed characters
+            var userName = request.UserName?.Trim();
+            if (string.IsNullOrWhiteSpace(userName))
+            {
+                userName = email;
+            }
+            else
+            {
+                // Replace whitespace with dots and filter to allowed Identity characters
+                userName = System.Text.RegularExpressions.Regex.Replace(userName, @"\s+", ".").ToLowerInvariant();
+                userName = System.Text.RegularExpressions.Regex.Replace(userName, @"[^a-z0-9_.\-@+]", "");
+                if (string.IsNullOrWhiteSpace(userName))
+                {
+                    userName = email;
+                }
+            }
+            request.UserName = userName;
+            request.Email = email;
+
             var createUserResult = await skorubaService.CreateUserAsync(request, cancellationToken);
 
             if (createUserResult.IsFailed)
-                return Result.Fail(CreateError.Create("Failed to create user."));
+                return Result.Fail(CreateError.Create(createUserResult.Errors.FirstOrDefault()?.Message ?? "Failed to create user."));
 
             var newUserId = Guid.Parse(createUserResult.Value.Trim());