Implement role and user management enhancements

- Added MaxIpLimit to roles, allowing for the configuration of simultaneous IP limits for users.
- Updated role creation and update commands to include MaxIpLimit, ensuring proper handling in the application logic.
- Enhanced user management by introducing a DELETE endpoint for user accounts, with appropriate checks to prevent self-deletion.
- Updated documentation to reflect changes in role and user management, clarifying the new IP limit functionality and user deletion process.
- Adjusted related tests to cover new functionality and ensure robust validation of role and user management features.

backend/src/PnvPanel.Infrastructure/Identity/IdentityService.cs

@@ -60,7 +60,8 @@ internal sealed class IdentityService(UserManager<AppUser> userManager, SignInMa
 
         var role = await GetPrimaryRoleAsync(user);
         return new CurrentUserProfile(
-            user.Id, user.UserName!, role.Id, role.Name!, user.IsActivated, user.IsBlocked, role.MaxConfigs, user.SubscriptionToken);
+            user.Id, user.UserName!, role.Id, role.Name!, user.IsActivated, user.IsBlocked, role.MaxConfigs, role.MaxIpLimit,
+            user.SubscriptionToken);
     }
 
     public async Task<Result> ChangePasswordAsync(Guid userId, string currentPassword, string newPassword, CancellationToken cancellationToken)