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/Telegram/GetLoginRequestStatusQueryHandler.cs

@@ -0,0 +1,48 @@
+using Microsoft.EntityFrameworkCore;
+using PnvPanel.Application.Auth;
+using PnvPanel.Application.Common.Interfaces;
+using PnvPanel.Application.Common.Messaging;
+using PnvPanel.Application.Common.Models;
+using PnvPanel.Domain.Telegram;
+
+namespace PnvPanel.Application.Telegram;
+
+/// <summary>
+/// Формально Query, но при первом наблюдении Approved-статуса атомарно "забирает" вход:
+/// выпускает JWT и переводит запрос в Consumed (одноразовый claim), см. api-design.md.
+/// Осознанное отступление от чистого CQRS ради простого поллинга без отдельного claim-эндпоинта.
+/// </summary>
+public sealed class GetLoginRequestStatusQueryHandler(
+    IAppDbContext dbContext, IIdentityService identityService, IJwtTokenService jwtTokenService, IRefreshTokenService refreshTokenService)
+    : IQueryHandler<GetLoginRequestStatusQuery, Result<LoginRequestStatusDto>>
+{
+    public async Task<Result<LoginRequestStatusDto>> Handle(GetLoginRequestStatusQuery query, CancellationToken cancellationToken)
+    {
+        var request = await dbContext.TelegramLoginRequests.FirstOrDefaultAsync(r => r.Id == query.RequestId, cancellationToken);
+        if (request is null)
+            return Result.Failure<LoginRequestStatusDto>(TelegramErrors.LoginRequestNotFound);
+
+        if (request.Status == TelegramLoginStatus.Pending && request.IsExpired)
+            return Result.Success(new LoginRequestStatusDto(TelegramLoginStatus.Expired, null));
+
+        if (request.Status != TelegramLoginStatus.Approved)
+            return Result.Success(new LoginRequestStatusDto(request.Status, null));
+
+        var profile = await identityService.GetProfileAsync(request.UserId!.Value, cancellationToken);
+        if (profile is null)
+            return Result.Failure<LoginRequestStatusDto>(AuthErrors.Unauthorized);
+
+        var authUser = new AuthenticatedUser(profile.Id, profile.UserName, profile.Role);
+        var (accessToken, accessExpiresAt) = jwtTokenService.GenerateAccessToken(authUser);
+
+        request.Consume();
+        // IssueAsync сохраняет весь SaveChanges (в т.ч. Consume() выше) — см. RefreshTokenService.
+        var refreshToken = await refreshTokenService.IssueAsync(profile.Id, cancellationToken);
+
+        // Пользователь только что подтвердил вход через бота — Telegram точно привязан.
+        var dto = new CurrentUserDto(profile.Id, profile.UserName, profile.Role, profile.IsActivated, TelegramLinked: true);
+        var auth = new AuthResult(accessToken, accessExpiresAt, refreshToken.RawToken, refreshToken.ExpiresAt, dto);
+
+        return Result.Success(new LoginRequestStatusDto(TelegramLoginStatus.Approved, auth));
+    }
+}