Add notification for ticket reopening to Telegram admins

- Implemented NotifyAdminsTicketReopenedAsync method in TelegramNotifier to notify admins when a ticket is reopened, including a link to the ticket on the public site.
- Updated ITelegramNotifier interface to include the new notification method.
- Modified ReopenTicketCommandHandler to invoke the new notification method after a ticket is reopened.
- Enhanced unit tests for ReopenTicketCommandHandler to verify the notification functionality.

backend/src/PnvPanel.Api/Telegram/TelegramNotifier.cs

@@ -1,5 +1,6 @@
 using Microsoft.Extensions.Options;
 using PnvPanel.Application.Common.Interfaces;
+using PnvPanel.Domain.Support;
 using PnvPanel.Infrastructure.Telegram;
 using Telegram.Bot;
 using Telegram.Bot.Types.Enums;
@@ -97,6 +98,35 @@ internal sealed class TelegramNotifier(ITelegramBotClient botClient, IIdentitySe
         }
     }
 
+    public async Task NotifyAdminsTicketReopenedAsync(Guid ticketId, string userName, TicketType type, CancellationToken cancellationToken)
+    {
+        if (string.IsNullOrWhiteSpace(options.Value.BotToken))
+            return;
+
+        var typeLabel = type == TicketType.RoleRequest ? "заявка на роль" : "баг/предложение";
+        var text = $"🔓 Тикет от <b>{Escape(userName)}</b> переоткрыт ({typeLabel})";
+
+        InlineKeyboardMarkup? keyboard = null;
+        if (!string.IsNullOrWhiteSpace(options.Value.PublicSiteUrl))
+        {
+            var url = $"{options.Value.PublicSiteUrl.TrimEnd('/')}/admin/support?ticket={ticketId}";
+            keyboard = new InlineKeyboardMarkup(new[] { InlineKeyboardButton.WithUrl("🌐 Открыть на сайте", url) });
+        }
+
+        foreach (var adminId in options.Value.ParseAdminTelegramUserIds())
+        {
+            try
+            {
+                await botClient.SendMessage(
+                    adminId, text, parseMode: ParseMode.Html, replyMarkup: keyboard, cancellationToken: cancellationToken);
+            }
+            catch
+            {
+                // Админ мог не запускать бота (нет чата с ботом) — пропускаем, не валим команду.
+            }
+        }
+    }
+
     public async Task NotifyUsersNewsPublishedAsync(string title, CancellationToken cancellationToken)
     {
         if (string.IsNullOrWhiteSpace(options.Value.BotToken))

backend/src/PnvPanel.Application/Common/Interfaces/ITelegramNotifier.cs

@@ -1,3 +1,5 @@
+using PnvPanel.Domain.Support;
+
 namespace PnvPanel.Application.Common.Interfaces;
 
 /// <summary>
@@ -25,4 +27,8 @@ public interface ITelegramNotifier
     /// <summary>Рассылка о публикации новости всем активированным пользователям с привязанным Telegram
     /// (кнопка-ссылка на сайт, где новость показана целиком).</summary>
     Task NotifyUsersNewsPublishedAsync(string title, CancellationToken cancellationToken);
+
+    /// <summary>Пользователь переоткрыл решённый тикет — только кнопка-ссылка на сайт, без
+    /// инлайн-действий (аналогично баг-репортам).</summary>
+    Task NotifyAdminsTicketReopenedAsync(Guid ticketId, string userName, TicketType type, CancellationToken cancellationToken);
 }

backend/src/PnvPanel.Application/Support/Reopen/ReopenTicketCommandHandler.cs

@@ -7,7 +7,7 @@ using PnvPanel.Domain.Support;
 
 namespace PnvPanel.Application.Support.Reopen;
 
-public sealed class ReopenTicketCommandHandler(IAppDbContext dbContext, ICurrentUser currentUser)
+public sealed class ReopenTicketCommandHandler(IAppDbContext dbContext, ITelegramNotifier telegramNotifier, ICurrentUser currentUser)
     : ICommandHandler<ReopenTicketCommand, Result>
 {
     public async Task<Result> Handle(ReopenTicketCommand command, CancellationToken cancellationToken)
@@ -24,6 +24,10 @@ public sealed class ReopenTicketCommandHandler(IAppDbContext dbContext, ICurrent
             return Result.Failure(SupportErrors.NotResolved);
 
         ticket.Reopen();
+
+        var userName = currentUser.UserName ?? userId.ToString();
+        await telegramNotifier.NotifyAdminsTicketReopenedAsync(ticket.Id, userName, ticket.Type, cancellationToken);
+
         return Result.Success();
     }
 }

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

@@ -1,3 +1,5 @@
+using NSubstitute;
+using PnvPanel.Application.Common.Interfaces;
 using PnvPanel.Application.Support;
 using PnvPanel.Application.Support.Reopen;
 using PnvPanel.Application.Tests.TestSupport;
@@ -8,6 +10,8 @@ namespace PnvPanel.Application.Tests.Support;
 
 public class ReopenTicketCommandHandlerTests
 {
+    private readonly ITelegramNotifier _telegramNotifier = Substitute.For<ITelegramNotifier>();
+
     [Fact]
     public async Task Handle_WhenResolved_SetsOpen()
     {
@@ -19,12 +23,14 @@ public class ReopenTicketCommandHandlerTests
         await dbContext.SaveChangesAsync(CancellationToken.None);
 
         var currentUser = FakeCurrentUser.Authenticated(userId);
-        var handler = new ReopenTicketCommandHandler(dbContext, currentUser);
+        var handler = new ReopenTicketCommandHandler(dbContext, _telegramNotifier, currentUser);
 
         var result = await handler.Handle(new ReopenTicketCommand(ticket.Id), CancellationToken.None);
 
         Assert.True(result.IsSuccess);
         Assert.Equal(TicketStatus.Open, ticket.Status);
+        await _telegramNotifier.Received(1).NotifyAdminsTicketReopenedAsync(
+            ticket.Id, Arg.Any<string>(), TicketType.BugReport, Arg.Any<CancellationToken>());
     }
 
     [Fact]
@@ -37,7 +43,7 @@ public class ReopenTicketCommandHandlerTests
         await dbContext.SaveChangesAsync(CancellationToken.None);
 
         var currentUser = FakeCurrentUser.Authenticated(userId);
-        var handler = new ReopenTicketCommandHandler(dbContext, currentUser);
+        var handler = new ReopenTicketCommandHandler(dbContext, _telegramNotifier, currentUser);
 
         var result = await handler.Handle(new ReopenTicketCommand(ticket.Id), CancellationToken.None);
 
@@ -55,7 +61,7 @@ public class ReopenTicketCommandHandlerTests
         await dbContext.SaveChangesAsync(CancellationToken.None);
 
         var currentUser = FakeCurrentUser.Authenticated(Guid.NewGuid());
-        var handler = new ReopenTicketCommandHandler(dbContext, currentUser);
+        var handler = new ReopenTicketCommandHandler(dbContext, _telegramNotifier, currentUser);
 
         var result = await handler.Handle(new ReopenTicketCommand(ticket.Id), CancellationToken.None);