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/CreateSession/CancelSessionHandler.cs

@@ -14,6 +14,7 @@ public sealed record CancelSessionCommand(
     long TelegramUserId,
     string CallbackQueryId,
     long ChatId,
+    int? MessageThreadId,
     int MessageId);
 
 // DTOs for AOT compilation
@@ -29,7 +30,7 @@ public sealed class CancelSessionHandler(
     {
         await using var connection = await dataSource.OpenConnectionAsync(ct);
         await using var transaction = await connection.BeginTransactionAsync(ct);
-        
+
         // 1. Проверяем, что запрос делает управляющий данной группы.
         var session = await connection.QuerySingleOrDefaultAsync<CancelSessionInfoDto>(
             """
@@ -117,9 +118,14 @@ public sealed class CancelSessionHandler(
                 ct);
 
             await bot.AnswerCallbackQuery(command.CallbackQueryId, "Сессия отменена!", cancellationToken: ct);
-            
+
             // Опционально: написать отдельное сообщение в чат
-            await bot.SendMessage(command.ChatId, $"❌ <b>Внимание!</b> Сессия \"{System.Net.WebUtility.HtmlEncode(session.Title)}\" отменена.", parseMode: Telegram.Bot.Types.Enums.ParseMode.Html, cancellationToken: ct);
+            await bot.SendMessage(
+                chatId: command.ChatId,
+                messageThreadId: command.MessageThreadId,
+                text: $"❌ <b>Внимание!</b> Сессия \"{System.Net.WebUtility.HtmlEncode(session.Title)}\" отменена.",
+                parseMode: Telegram.Bot.Types.Enums.ParseMode.Html,
+                cancellationToken: ct);
 
             var mode = SessionNotificationModeExtensions.FromDatabaseValue(session.NotificationMode);
             if (mode.ShouldSendDirectMessages())