Implement support ticket system with role request and bug report functionalities

- Introduced a new support ticket system allowing users to submit bug reports and role requests.
- Implemented endpoints for creating, updating, and managing support tickets, including file attachments.
- Enhanced Telegram bot integration to handle role requests directly within the bot, enabling admins to approve or reject requests without accessing the website.
- Updated database schema to include support ticket entities and their relationships.
- Improved API documentation to reflect new support ticket endpoints and their usage.
- Added necessary localization for support ticket features in both Russian and English.

backend/tests/PnvPanel.Application.Tests/Support/CreateBugReportTicketCommandHandlerTests.cs

@@ -0,0 +1,71 @@
+using NSubstitute;
+using PnvPanel.Application.Common.Interfaces;
+using PnvPanel.Application.Support;
+using PnvPanel.Application.Support.CreateBugReport;
+using PnvPanel.Application.Tests.TestSupport;
+using PnvPanel.Domain.Support;
+using Xunit;
+
+namespace PnvPanel.Application.Tests.Support;
+
+public class CreateBugReportTicketCommandHandlerTests
+{
+    private readonly IFileStorage _fileStorage = Substitute.For<IFileStorage>();
+    private readonly IRealtimeNotifier _notifier = Substitute.For<IRealtimeNotifier>();
+    private readonly ITelegramNotifier _telegramNotifier = Substitute.For<ITelegramNotifier>();
+
+    [Fact]
+    public async Task Handle_WithValidMessage_CreatesTicketAndComment()
+    {
+        using var dbContext = InMemoryDbContextFactory.Create();
+        var userId = Guid.NewGuid();
+        var currentUser = FakeCurrentUser.Authenticated(userId, "alice");
+
+        var handler = new CreateBugReportTicketCommandHandler(dbContext, _fileStorage, _notifier, _telegramNotifier, currentUser);
+
+        var result = await handler.Handle(new CreateBugReportTicketCommand("Что-то сломалось", []), CancellationToken.None);
+        await dbContext.SaveChangesAsync(CancellationToken.None);
+
+        Assert.True(result.IsSuccess);
+        Assert.Equal(TicketType.BugReport, result.Value.Type);
+        Assert.Equal(TicketStatus.Open, result.Value.Status);
+        Assert.Single(result.Value.Comments);
+        Assert.Equal("Что-то сломалось", result.Value.Comments[0].Body);
+        Assert.Single(dbContext.SupportTickets);
+        Assert.Single(dbContext.TicketComments);
+        await _telegramNotifier.Received(1).NotifyAdminsBugReportCreatedAsync(
+            Arg.Any<Guid>(), "alice", "Что-то сломалось", Arg.Any<CancellationToken>());
+    }
+
+    [Fact]
+    public async Task Handle_WithTooManyAttachments_ReturnsValidationError()
+    {
+        using var dbContext = InMemoryDbContextFactory.Create();
+        var currentUser = FakeCurrentUser.Authenticated(Guid.NewGuid());
+        var attachments = Enumerable.Range(0, 6)
+            .Select(_ => new TicketAttachmentUpload(new MemoryStream(), "a.png", "image/png", 10))
+            .ToList();
+
+        var handler = new CreateBugReportTicketCommandHandler(dbContext, _fileStorage, _notifier, _telegramNotifier, currentUser);
+
+        var result = await handler.Handle(new CreateBugReportTicketCommand("текст", attachments), CancellationToken.None);
+
+        Assert.False(result.IsSuccess);
+        Assert.Equal(SupportErrors.TooManyAttachments, result.Error);
+    }
+
+    [Fact]
+    public async Task Handle_WithUnsupportedAttachmentType_ReturnsValidationError()
+    {
+        using var dbContext = InMemoryDbContextFactory.Create();
+        var currentUser = FakeCurrentUser.Authenticated(Guid.NewGuid());
+        var attachments = new[] { new TicketAttachmentUpload(new MemoryStream(), "a.exe", "application/x-msdownload", 10) };
+
+        var handler = new CreateBugReportTicketCommandHandler(dbContext, _fileStorage, _notifier, _telegramNotifier, currentUser);
+
+        var result = await handler.Handle(new CreateBugReportTicketCommand("текст", attachments), CancellationToken.None);
+
+        Assert.False(result.IsSuccess);
+        Assert.Equal(SupportErrors.UnsupportedAttachmentType, result.Error);
+    }
+}