Add Telegram bot integration and enhance user management features

- Introduced Telegram.Bot package for bot functionality.
- Updated user management to include Telegram linking and blocking features.
- Enhanced activation request handling with notifications via Telegram.
- Added new database entities for Telegram link tokens and login requests.
- Implemented traffic synchronization for client stats in the XuiPanelGateway.
- Updated application structure to support new test projects and improved dependency injection for Telegram services.

backend/src/PnvPanel.Application/Admin/Users/ListUsersQueryHandler.cs

@@ -0,0 +1,18 @@
+using PnvPanel.Application.Common.Interfaces;
+using PnvPanel.Application.Common.Messaging;
+using PnvPanel.Application.Common.Models;
+
+namespace PnvPanel.Application.Admin.Users;
+
+public sealed class ListUsersQueryHandler(IIdentityService identityService)
+    : IQueryHandler<ListUsersQuery, Result<PagedList<UserSummaryDto>>>
+{
+    public async Task<Result<PagedList<UserSummaryDto>>> Handle(ListUsersQuery query, CancellationToken cancellationToken)
+    {
+        var page = query.Page <= 0 ? 1 : query.Page;
+        var pageSize = query.PageSize is <= 0 or > 100 ? 20 : query.PageSize;
+
+        var result = await identityService.ListUsersAsync(page, pageSize, query.Search, cancellationToken);
+        return Result.Success(result);
+    }
+}