Implement message preview feature for support tickets

- Added a new property `MessagePreview` to the `TicketSummaryDto` to display the truncated first message of a ticket.
- Updated the `TicketMapping` class to retrieve the first message for each ticket and truncate it for preview purposes.
- Modified the `SupportTicketList` and `AdminSupportPage` components to conditionally render the message preview in the ticket list, enhancing user experience by providing context at a glance.

backend/src/PnvPanel.Application/Support/TicketMapping.cs

@@ -99,6 +99,18 @@ internal static class TicketMapping
             .Select(g => new { TicketId = g.Key, Last = g.Max(c => c.CreatedAt) })
             .ToDictionaryAsync(x => x.TicketId, x => x.Last, cancellationToken);
 
+        // Первое сообщение (не последний комментарий) — это исходный текст обращения, а не переписка.
+        var firstMessages = await dbContext
+            .TicketComments.AsNoTracking()
+            .Where(c => ticketIds.Contains(c.TicketId))
+            .GroupBy(c => c.TicketId)
+            .Select(g => new
+            {
+                TicketId = g.Key,
+                Body = g.OrderBy(c => c.CreatedAt).Select(c => c.Body).First(),
+            })
+            .ToDictionaryAsync(x => x.TicketId, x => x.Body, cancellationToken);
+
         var userIds = tickets.Select(t => t.UserId).Distinct().ToList();
         var userNames = await identityService.GetUserNamesAsync(userIds, cancellationToken);
 
@@ -110,8 +122,17 @@ internal static class TicketMapping
                 t.Type,
                 t.Status,
                 t.CreatedAt,
-                lastActivity.GetValueOrDefault(t.Id, t.CreatedAt)
+                lastActivity.GetValueOrDefault(t.Id, t.CreatedAt),
+                TruncatePreview(firstMessages.GetValueOrDefault(t.Id))
             ))
             .ToList();
     }
+
+    private static string? TruncatePreview(string? message)
+    {
+        if (string.IsNullOrEmpty(message))
+            return message;
+
+        return message.Length > 200 ? message[..200] + "…" : message;
+    }
 }

backend/src/PnvPanel.Application/Support/TicketSummaryDto.cs

@@ -3,7 +3,8 @@ using PnvPanel.Domain.Support;
 namespace PnvPanel.Application.Support;
 
 /// <summary>Строка списка тикетов — свой (ListMyTicketsQuery) и админский (ListAllTicketsQuery) списки
-/// используют один и тот же DTO (владелец видит только свои UserId/UserName — не секрет для себя).</summary>
+/// используют один и тот же DTO (владелец видит только свои UserId/UserName — не секрет для себя).
+/// MessagePreview — начало первого сообщения тикета (обрезано), для превью в списке.</summary>
 public sealed record TicketSummaryDto(
     Guid Id,
     Guid UserId,
@@ -11,5 +12,6 @@ public sealed record TicketSummaryDto(
     TicketType Type,
     TicketStatus Status,
     DateTimeOffset CreatedAt,
-    DateTimeOffset LastActivityAt
+    DateTimeOffset LastActivityAt,
+    string? MessagePreview
 );

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

@@ -0,0 +1,84 @@
+using NSubstitute;
+using PnvPanel.Application.Common.Interfaces;
+using PnvPanel.Application.Support;
+using PnvPanel.Application.Support.ListMyTickets;
+using PnvPanel.Application.Tests.TestSupport;
+using PnvPanel.Domain.Support;
+using Xunit;
+
+namespace PnvPanel.Application.Tests.Support;
+
+public class ListMyTicketsQueryHandlerTests
+{
+    private readonly IIdentityService _identityService = Substitute.For<IIdentityService>();
+
+    [Fact]
+    public async Task Handle_ReturnsFirstMessageAsPreview_NotLastComment()
+    {
+        using var dbContext = InMemoryDbContextFactory.Create();
+        var userId = Guid.NewGuid();
+        var ticket = SupportTicket.CreateBugReport(userId);
+        dbContext.SupportTickets.Add(ticket);
+
+        var firstComment = TicketComment.Create(ticket.Id, userId, "исходное сообщение о баге");
+        dbContext.TicketComments.Add(firstComment);
+        await dbContext.SaveChangesAsync(CancellationToken.None);
+
+        // Гарантируем, что второй комментарий получит более поздний CreatedAt (UtcNow может
+        // совпасть при быстром последовательном создании без явного clock-абстрагирования).
+        await Task.Delay(5, CancellationToken.None);
+        var replyComment = TicketComment.Create(
+            ticket.Id,
+            userId,
+            "более поздний ответ администратора"
+        );
+        dbContext.TicketComments.Add(replyComment);
+        await dbContext.SaveChangesAsync(CancellationToken.None);
+
+        _identityService
+            .GetUserNamesAsync(Arg.Any<IReadOnlyCollection<Guid>>(), Arg.Any<CancellationToken>())
+            .Returns(new Dictionary<Guid, string> { [userId] = "alice" });
+
+        var currentUser = FakeCurrentUser.Authenticated(userId, "alice");
+        var handler = new ListMyTicketsQueryHandler(dbContext, _identityService, currentUser);
+
+        var result = await handler.Handle(
+            new ListMyTicketsQuery(TypeFilter: null, StatusFilter: null, Page: 1, PageSize: 20),
+            CancellationToken.None
+        );
+
+        Assert.True(result.IsSuccess);
+        var summary = Assert.Single(result.Value.Items);
+        Assert.Equal("исходное сообщение о баге", summary.MessagePreview);
+    }
+
+    [Fact]
+    public async Task Handle_TruncatesLongMessagePreview()
+    {
+        using var dbContext = InMemoryDbContextFactory.Create();
+        var userId = Guid.NewGuid();
+        var ticket = SupportTicket.CreateBugReport(userId);
+        dbContext.SupportTickets.Add(ticket);
+
+        var longBody = new string('x', 250);
+        dbContext.TicketComments.Add(TicketComment.Create(ticket.Id, userId, longBody));
+        await dbContext.SaveChangesAsync(CancellationToken.None);
+
+        _identityService
+            .GetUserNamesAsync(Arg.Any<IReadOnlyCollection<Guid>>(), Arg.Any<CancellationToken>())
+            .Returns(new Dictionary<Guid, string> { [userId] = "alice" });
+
+        var currentUser = FakeCurrentUser.Authenticated(userId, "alice");
+        var handler = new ListMyTicketsQueryHandler(dbContext, _identityService, currentUser);
+
+        var result = await handler.Handle(
+            new ListMyTicketsQuery(TypeFilter: null, StatusFilter: null, Page: 1, PageSize: 20),
+            CancellationToken.None
+        );
+
+        Assert.True(result.IsSuccess);
+        var summary = Assert.Single(result.Value.Items);
+        Assert.Equal(201, summary.MessagePreview!.Length);
+        Assert.EndsWith("…", summary.MessagePreview);
+    }
+}

frontend/src/features/support/SupportTicketList.tsx

@@ -52,7 +52,8 @@ export function SupportTicketList() {
                 <CardTitle className="text-base">{t(`support.type.${ticket.type}`)}</CardTitle>
                 <TicketStatusBadge status={ticket.status} />
               </CardHeader>
-              <CardContent>
+              <CardContent className="flex flex-col gap-1">
+                {ticket.messagePreview && <p className="truncate text-xs text-muted-foreground">{ticket.messagePreview}</p>}
                 <p className="text-xs text-muted-foreground">
                   {t('support.lastActivity', { date: new Date(ticket.lastActivityAt).toLocaleString() })}
                 </p>

frontend/src/routes/admin/support.tsx

@@ -55,7 +55,8 @@ function AdminSupportPage() {
                 </CardTitle>
                 <TicketStatusBadge status={ticket.status} />
               </CardHeader>
-              <CardContent>
+              <CardContent className="flex flex-col gap-1">
+                {ticket.messagePreview && <p className="truncate text-xs text-muted-foreground">{ticket.messagePreview}</p>}
                 <p className="text-xs text-muted-foreground">
                   {t('support.lastActivity', { date: new Date(ticket.lastActivityAt).toLocaleString() })}
                 </p>

frontend/src/shared/api/types.ts

@@ -267,6 +267,7 @@ export type TicketSummaryDto = {
   status: TicketStatus
   createdAt: string
   lastActivityAt: string
+  messagePreview: string | null
 }
 
 export type TicketDetailDto = {