Guard null user fields in auth claims

Controllers/AuthController.cs

@@ -145,11 +145,14 @@ public class AuthController : ControllerBase
 
         var roles = await _userManager.GetRolesAsync(user);
 
+        var displayName = user.Name ?? user.Email ?? string.Empty;
+        var userEmail = user.Email ?? string.Empty;
+
         var claims = new List<Claim>
         {
             new(JwtRegisteredClaimNames.Sub, user.Id.ToString()),
-            new(JwtRegisteredClaimNames.Email, user.Email ?? string.Empty),
-            new("name", user.Name),
+            new(JwtRegisteredClaimNames.Email, userEmail),
+            new("name", displayName),
             new("tenantId", tenantId.ToString())
         };