feat: support co-gm group delegation

src/GmRelay.Bot/Features/Sessions/CreateSession/CancelSessionHandler.cs

@@ -16,7 +16,7 @@ public sealed record CancelSessionCommand(
     int MessageId);
 
 // DTOs for AOT compilation
-internal sealed record CancelSessionInfoDto(string Title, Guid BatchId, long GmId, string NotificationMode);
+internal sealed record CancelSessionInfoDto(string Title, Guid BatchId, bool CanManage, string NotificationMode);
 
 public sealed class CancelSessionHandler(
     NpgsqlDataSource dataSource,
@@ -29,13 +29,23 @@ 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 ГМ данной сессии
+        // 1. Проверяем, что запрос делает управляющий данной группы.
         var session = await connection.QuerySingleOrDefaultAsync<CancelSessionInfoDto>(
-            @"SELECT s.title as Title, s.batch_id as BatchId, g.gm_telegram_id as GmId, s.notification_mode as NotificationMode
-              FROM sessions s
-              JOIN game_groups g ON s.group_id = g.id
-              WHERE s.id = @SessionId",
-            new { command.SessionId }, transaction);
+            """
+            SELECT s.title AS Title,
+                   s.batch_id AS BatchId,
+                   s.notification_mode AS NotificationMode,
+                   EXISTS (
+                       SELECT 1
+                       FROM group_managers gm
+                       JOIN players p ON p.id = gm.player_id
+                       WHERE gm.group_id = s.group_id
+                         AND p.telegram_id = @TelegramUserId
+                   ) AS CanManage
+            FROM sessions s
+            WHERE s.id = @SessionId
+            """,
+            new { command.SessionId, command.TelegramUserId }, transaction);
 
         if (session == null)
         {
@@ -43,9 +53,9 @@ public sealed class CancelSessionHandler(
             return;
         }
 
-        if (session.GmId != command.TelegramUserId)
+        if (!session.CanManage)
         {
-            await bot.AnswerCallbackQuery(command.CallbackQueryId, "Только Мастер Игры (GM) может отменять сессию.", showAlert: true, cancellationToken: ct);
+            await bot.AnswerCallbackQuery(command.CallbackQueryId, "Только owner или co-GM может отменять сессию.", showAlert: true, cancellationToken: ct);
             return;
         }