refactor: extract remaining Telegram handlers to platform-neutral contracts

- Extract CreateSessionHandler, ListSessionsHandler, DeleteSessionHandler,
  ExportCalendarHandler, HandleRescheduleTimeInputHandler,
  HandleRescheduleVoteHandler to GmRelay.Shared
- Add IPlatformMessenger methods: SendScheduleAsync, UpdateScheduleAsync,
  SendGroupMessageAsync with actions, CreateThreadAsync, DeleteThreadAsync
- Rewrite Telegram Bot wrappers as thin adapters delegating to shared handlers
- Rewrite DiscordRescheduleVoteHandler to use shared HandleRescheduleVoteHandler
- Update UpdateRouter with explicit type aliases for ambiguous handler names
- Add contract and source-inspection tests for extracted handlers
- Bump version 3.1.1 → 3.2.0

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/GmRelay.Shared/Features/Sessions/ListSessions/DeleteSessionHandler.cs

@@ -0,0 +1,91 @@
+using Dapper;
+using GmRelay.Shared.Domain;
+using GmRelay.Shared.Platform;
+using Microsoft.Extensions.Logging;
+using Npgsql;
+
+namespace GmRelay.Shared.Features.Sessions.ListSessions;
+
+internal sealed record DeleteSessionInfoDto(
+    string Title,
+    Guid BatchId,
+    Guid GroupId,
+    bool CanManage,
+    int? ThreadId,
+    bool TopicCreatedByBot);
+
+public sealed record DeleteSessionResult(
+    bool Success,
+    string? ReplyText,
+    string? Title,
+    Guid? GroupId,
+    int? ThreadId,
+    bool TopicCreatedByBot,
+    int RemainingInTopic);
+
+public sealed class DeleteSessionHandler(
+    NpgsqlDataSource dataSource)
+{
+    public async Task<DeleteSessionResult> HandleAsync(DeleteSessionCommand command, CancellationToken ct)
+    {
+        await using var connection = await dataSource.OpenConnectionAsync(ct);
+        await using var transaction = await connection.BeginTransactionAsync(ct);
+
+        // 1. Fetch session and verify group manager.
+        var session = await connection.QuerySingleOrDefaultAsync<DeleteSessionInfoDto>(
+            """
+            SELECT s.title AS Title,
+                   s.batch_id AS BatchId,
+                   s.group_id AS GroupId,
+                   s.thread_id AS ThreadId,
+                   s.topic_created_by_bot AS TopicCreatedByBot,
+                   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.platform = @Platform
+                       AND p.external_user_id = @ExternalUserId
+                   ) AS CanManage
+            FROM sessions s
+            WHERE s.id = @SessionId
+            """,
+            new { command.SessionId, Platform = command.User.Platform.ToString(), ExternalUserId = command.User.ExternalUserId }, transaction);
+
+        if (session == null)
+        {
+            return new DeleteSessionResult(false, "Сессия не найдена.", null, null, null, false, 0);
+        }
+
+        if (!session.CanManage)
+        {
+            return new DeleteSessionResult(false, "Только owner или co-GM может удалять сессию.", null, null, null, false, 0);
+        }
+
+        // 2. Delete session
+        await connection.ExecuteAsync("DELETE FROM sessions WHERE id = @Id", new { Id = command.SessionId }, transaction);
+
+        var remainingInTopic = session.ThreadId.HasValue
+            ? await connection.ExecuteScalarAsync<int>(
+                """
+                SELECT COUNT(*)
+                FROM sessions
+                WHERE group_id = @GroupId
+                  AND thread_id = @ThreadId
+                """,
+                new { session.GroupId, ThreadId = session.ThreadId.Value },
+                transaction)
+            : 0;
+
+        await transaction.CommitAsync(ct);
+
+        return new DeleteSessionResult(
+            true,
+            "Сессия удалена!",
+            session.Title,
+            session.GroupId,
+            session.ThreadId,
+            session.TopicCreatedByBot,
+            remainingInTopic);
+    }
+}

src/GmRelay.Shared/Features/Sessions/ListSessions/ListSessionsCommand.cs

@@ -0,0 +1,13 @@
+using GmRelay.Shared.Platform;
+
+namespace GmRelay.Shared.Features.Sessions.ListSessions;
+
+public sealed record ListSessionsCommand(
+    PlatformGroup Group,
+    PlatformUser User);
+
+public sealed record DeleteSessionCommand(
+    Guid SessionId,
+    PlatformUser User,
+    PlatformGroup Group,
+    PlatformMessageRef ScheduleMessage);

src/GmRelay.Shared/Features/Sessions/ListSessions/ListSessionsHandler.cs

@@ -0,0 +1,57 @@
+using Dapper;
+using GmRelay.Shared.Domain;
+using GmRelay.Shared.Platform;
+using Npgsql;
+
+namespace GmRelay.Shared.Features.Sessions.ListSessions;
+
+public sealed record SessionListItemDto(Guid Id, string Title, DateTime ScheduledAt, string Status, int? MaxPlayers, int PlayerCount, int WaitlistCount, bool CanManage);
+
+public sealed record SessionListResult(
+    IReadOnlyList<SessionListItemDto> Sessions,
+    bool CanManage);
+
+public sealed class ListSessionsHandler(
+    NpgsqlDataSource dataSource)
+{
+    public async Task<SessionListResult> HandleAsync(ListSessionsCommand command, CancellationToken cancellationToken)
+    {
+        await using var connection = await dataSource.OpenConnectionAsync(cancellationToken);
+
+        var sessions = await connection.QueryAsync<SessionListItemDto>(
+            @"SELECT s.id as Id, s.title as Title, s.scheduled_at as ScheduledAt, s.status as Status, s.max_players as MaxPlayers,
+                     COUNT(sp.id) FILTER (WHERE sp.is_gm = false AND sp.registration_status = @Active) as PlayerCount,
+                     COUNT(sp.id) FILTER (WHERE sp.is_gm = false AND sp.registration_status = @Waitlisted) as WaitlistCount,
+                     EXISTS (
+                         SELECT 1
+                         FROM group_managers gm
+                         JOIN players manager_player ON manager_player.id = gm.player_id
+                         WHERE gm.group_id = s.group_id
+                           AND manager_player.platform = @Platform
+                           AND manager_player.external_user_id = @ExternalUserId
+                     ) AS CanManage
+              FROM sessions s
+              JOIN game_groups g ON s.group_id = g.id
+              LEFT JOIN session_participants sp ON s.id = sp.session_id
+              WHERE g.platform = @Platform
+                AND g.external_group_id = @ExternalGroupId
+                AND s.status != @Cancelled
+                AND s.scheduled_at > NOW()
+              GROUP BY s.id, s.title, s.scheduled_at, s.status, s.max_players, s.group_id
+              ORDER BY s.scheduled_at ASC",
+            new
+            {
+                Platform = command.Group.Platform.ToString(),
+                ExternalGroupId = command.Group.ExternalGroupId,
+                ExternalUserId = command.User.ExternalUserId,
+                Cancelled = SessionStatus.Cancelled,
+                Active = ParticipantRegistrationStatus.Active,
+                Waitlisted = ParticipantRegistrationStatus.Waitlisted
+            });
+
+        var sessionsList = sessions.ToList();
+        var canManage = sessionsList.Count > 0 && sessionsList.First().CanManage;
+
+        return new SessionListResult(sessionsList, canManage);
+    }
+}