feat(#21): support selected telegram topics for schedules

Route new schedules to an existing forum topic when /newsession is sent inside one, create bot-owned topics only from the forum root, and keep group notifications/dashboard updates threaded to the stored topic.

Persist topic ownership so deletion only removes empty bot-created topics, add topic routing tests and smoke coverage, and bump release metadata to 1.14.0.

src/GmRelay.Bot/Features/Sessions/RescheduleSession/HandleRescheduleTimeInputHandler.cs

@@ -14,7 +14,7 @@ namespace GmRelay.Bot.Features.Sessions.RescheduleSession;
 
 internal sealed record AwaitingProposalDto(
     Guid Id, Guid SessionId, string Title, DateTime CurrentScheduledAt,
-    Guid BatchId, int? BatchMessageId, long TelegramChatId, string NotificationMode);
+    Guid BatchId, int? BatchMessageId, long TelegramChatId, int? ThreadId, string NotificationMode);
 
 internal sealed record VoteParticipantDto(
     Guid PlayerId,
@@ -57,6 +57,7 @@ public sealed class HandleRescheduleTimeInputHandler(
             SELECT rp.id AS Id, rp.session_id AS SessionId, s.title AS Title, s.scheduled_at AS CurrentScheduledAt,
                    s.batch_id AS BatchId, s.batch_message_id AS BatchMessageId,
                    g.telegram_chat_id AS TelegramChatId,
+                   s.thread_id AS ThreadId,
                    s.notification_mode AS NotificationMode
             FROM reschedule_proposals rp
             JOIN sessions s ON s.id = rp.session_id
@@ -84,6 +85,7 @@ public sealed class HandleRescheduleTimeInputHandler(
         {
             await bot.SendMessage(
                 chatId: chatId,
+                messageThreadId: proposal.ThreadId,
                 text: $"⚠️ {parseError}\n\nИспользуйте формат:\n<code>25.04.2026 19:30\n26.04.2026 18:00\nДедлайн: 25.04.2026 12:00</code>",
                 parseMode: Telegram.Bot.Types.Enums.ParseMode.Html,
                 cancellationToken: ct);
@@ -161,6 +163,7 @@ public sealed class HandleRescheduleTimeInputHandler(
 
         var voteMsg = await bot.SendMessage(
             chatId: chatId,
+            messageThreadId: proposal.ThreadId,
             text: voteText,
             parseMode: Telegram.Bot.Types.Enums.ParseMode.Html,
             replyMarkup: keyboard,
@@ -242,6 +245,7 @@ public sealed class HandleRescheduleTimeInputHandler(
 
         await bot.SendMessage(
             chatId: chatId,
+            messageThreadId: proposal.ThreadId,
             text: $"✅ Сессия «{proposal.Title}» перенесена!\n\n📅 Новое время: <b>{newTime.ToOffset(TimeSpan.FromHours(3)).ToString("d MMMM yyyy, HH:mm", System.Globalization.CultureInfo.GetCultureInfo("ru-RU"))}</b> (МСК)\n\n<i>Участников нет — голосование не требуется.</i>",
             parseMode: Telegram.Bot.Types.Enums.ParseMode.Html,
             cancellationToken: ct);