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.Application/Configs/Create/CreateVpnConfigCommandHandler.cs

@@ -44,7 +44,7 @@ public sealed class CreateVpnConfigCommandHandler(
 
         var addResult = await gateway.AddClientAsync(
             node, inbound.RemoteInboundId, inbound.Protocol, config.ClientEmail,
-            config.Label ?? config.ClientEmail, cancellationToken);
+            config.Label ?? config.ClientEmail, profile.MaxIpLimit, cancellationToken);
 
         if (!addResult.IsSuccess)
         {

backend/src/PnvPanel.Application/Configs/Rotate/RotateVpnConfigCommandHandler.cs

@@ -7,7 +7,8 @@ using PnvPanel.Domain.Configs;
 
 namespace PnvPanel.Application.Configs.Rotate;
 
-public sealed class RotateVpnConfigCommandHandler(IAppDbContext dbContext, IXuiPanelGateway gateway, ICurrentUser currentUser)
+public sealed class RotateVpnConfigCommandHandler(
+    IAppDbContext dbContext, IXuiPanelGateway gateway, IIdentityService identityService, ICurrentUser currentUser)
     : ICommandHandler<RotateVpnConfigCommand, Result<VpnConfigDto>>
 {
     public async Task<Result<VpnConfigDto>> Handle(RotateVpnConfigCommand command, CancellationToken cancellationToken)
@@ -32,10 +33,14 @@ public sealed class RotateVpnConfigCommandHandler(IAppDbContext dbContext, IXuiP
         if (node is null)
             return Result.Failure<VpnConfigDto>(ConfigErrors.NodeDisabled);
 
+        var profile = await identityService.GetProfileAsync(userId, cancellationToken);
+        if (profile is null)
+            return Result.Failure<VpnConfigDto>(AuthErrors.Unauthorized);
+
         var newClientEmail = VpnConfig.GenerateClientEmail(userId);
         var addResult = await gateway.AddClientAsync(
             node, inbound.RemoteInboundId, config.Protocol, newClientEmail,
-            config.Label ?? newClientEmail, cancellationToken);
+            config.Label ?? newClientEmail, profile.MaxIpLimit, cancellationToken);
 
         if (!addResult.IsSuccess)
             return Result.Failure<VpnConfigDto>(addResult.Error);