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/tests/PnvPanel.Application.Tests/Auth/GetCurrentUserQueryHandlerTests.cs

@@ -0,0 +1,59 @@
+using NSubstitute;
+using PnvPanel.Application.Auth;
+using PnvPanel.Application.Auth.Me;
+using PnvPanel.Application.Common.Interfaces;
+using PnvPanel.Application.Tests.TestSupport;
+using Xunit;
+
+namespace PnvPanel.Application.Tests.Auth;
+
+public class GetCurrentUserQueryHandlerTests
+{
+    private readonly IIdentityService _identityService = Substitute.For<IIdentityService>();
+
+    [Fact]
+    public async Task Handle_Unauthenticated_ReturnsUnauthorized()
+    {
+        var handler = new GetCurrentUserQueryHandler(_identityService, FakeCurrentUser.Anonymous());
+
+        var result = await handler.Handle(new GetCurrentUserQuery(), CancellationToken.None);
+
+        Assert.False(result.IsSuccess);
+        Assert.Equal(AuthErrors.Unauthorized, result.Error);
+    }
+
+    [Fact]
+    public async Task Handle_ProfileMissing_ReturnsUnauthorized()
+    {
+        var userId = Guid.NewGuid();
+        _identityService.GetProfileAsync(userId, Arg.Any<CancellationToken>()).Returns((CurrentUserProfile?)null);
+
+        var handler = new GetCurrentUserQueryHandler(_identityService, FakeCurrentUser.Authenticated(userId));
+
+        var result = await handler.Handle(new GetCurrentUserQuery(), CancellationToken.None);
+
+        Assert.False(result.IsSuccess);
+        Assert.Equal(AuthErrors.Unauthorized, result.Error);
+    }
+
+    [Fact]
+    public async Task Handle_AuthenticatedWithProfile_ReturnsCurrentUserDto()
+    {
+        var userId = Guid.NewGuid();
+        var profile = new CurrentUserProfile(userId, "alice", Guid.NewGuid(), "user", true, false, 3);
+        _identityService.GetProfileAsync(userId, Arg.Any<CancellationToken>()).Returns(profile);
+        _identityService.GetTelegramLinkInfoAsync(userId, Arg.Any<CancellationToken>())
+            .Returns(new TelegramLinkInfo(true, 42, "alice_tg"));
+
+        var handler = new GetCurrentUserQueryHandler(_identityService, FakeCurrentUser.Authenticated(userId, "alice"));
+
+        var result = await handler.Handle(new GetCurrentUserQuery(), CancellationToken.None);
+
+        Assert.True(result.IsSuccess);
+        Assert.Equal(userId, result.Value.Id);
+        Assert.Equal("alice", result.Value.UserName);
+        Assert.Equal("user", result.Value.Role);
+        Assert.True(result.Value.IsActivated);
+        Assert.True(result.Value.TelegramLinked);
+    }
+}