Merge pull request #104: refactor: завершить platform migration и удалить deprecated telegram_* scaffolding

- Migrated all core domain SQL from telegram_* columns to platform + external_*
- Added V024/V025 migrations with backfill and deprecation comments
- Removed all COALESCE(external_*, telegram_*) fallbacks
- Replaced gm_telegram_id join with group_managers query in HandleRsvpHandler
- Updated Bot, Web, DiscordBot, and Shared handlers
- Bumped version to 3.1.0

CI run #265 passed (289 tests, 0 warnings, 0 vulnerabilities)

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

.gitea/workflows/deploy.yml

@@ -6,7 +6,7 @@ on:
       - main 
 
 env:
-  VERSION: 2.8.0
+  VERSION: 3.1.0
 
 jobs:
   # ЧАСТЬ 1: Собираем образы и кладем в Gitea (чтобы делиться с ребятами)

Directory.Build.props

@@ -1,6 +1,6 @@
 <Project>
   <PropertyGroup>
-    <Version>2.8.0</Version>
+    <Version>3.1.0</Version>
     <TargetFramework>net10.0</TargetFramework>
     <LangVersion>preview</LangVersion>
     <Nullable>enable</Nullable>

README.md

@@ -85,8 +85,10 @@ TELEGRAM_BOT_TOKEN=ваш_токен_здесь
 # Токен Discord application bot
 DISCORD_BOT_TOKEN=ваш_discord_токен_здесь
 
-# Client ID Discord application (используется для slash-команд)
-DISCORD_BOT_CLIENT_ID=ваш_discord_client_id_здесь
+# Discord OAuth (для Web Dashboard)
+DISCORD_CLIENT_ID=ваш_discord_client_id_здесь
+DISCORD_CLIENT_SECRET=ваш_discord_client_secret_здесь
+DISCORD_REDIRECT_URI=https://your-domain.example/auth/discord/callback
 
 # Имя бота без @ (для Telegram Login Widget)
 TELEGRAM_BOT_USERNAME=ваше_имя_бота_здесь
@@ -119,7 +121,7 @@ docker compose up -d
 1. Напишите боту `/start`.
 2. Создайте группу через `/newgroup`.
 3. Откройте Mini App или Web Dashboard для расширенного управления.
-4. Для Discord пригласите application bot на сервер с правами `bot` и `applications.commands`. Скопируйте `DISCORD_BOT_TOKEN` и `DISCORD_BOT_CLIENT_ID` в `.env`.
+4. Для Discord пригласите application bot на сервер с правами `bot` и `applications.commands`. Скопируйте `DISCORD_BOT_TOKEN` в `.env`; `DISCORD_CLIENT_ID`, `DISCORD_CLIENT_SECRET` и `DISCORD_REDIRECT_URI` нужны только для входа в Web Dashboard через Discord.
 5. Перезапустите Docker Compose (`docker compose up -d`), а затем в Discord создайте сессию через `/newsession` или опубликуйте расписание через `/listsessions`; игроки записываются и выходят кнопками в опубликованном сообщении.
 
 ## 💾 Backup и восстановление

compose.yaml

@@ -49,7 +49,7 @@ services:
         crond -f
 
   bot:
-    image: git.codeanddice.ru/toutsu/gmrelay-bot:2.8.0
+    image: git.codeanddice.ru/toutsu/gmrelay-bot:3.1.0
     restart: always
     depends_on:
       db:
@@ -67,7 +67,7 @@ services:
       retries: 3
 
   discord:
-    image: git.codeanddice.ru/toutsu/gmrelay-discord-bot:2.8.0
+    image: git.codeanddice.ru/toutsu/gmrelay-discord-bot:3.1.0
     restart: always
     depends_on:
       db:
@@ -84,7 +84,7 @@ services:
       retries: 3
 
   web:
-    image: git.codeanddice.ru/toutsu/gmrelay-web:2.8.0
+    image: git.codeanddice.ru/toutsu/gmrelay-web:3.1.0
     restart: always
     depends_on:
       db:

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

@@ -42,12 +42,13 @@ public sealed class CancelSessionHandler(
                        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
+                         AND p.platform = 'Telegram'
+                         AND p.external_user_id = @ExternalUserId
                    ) AS CanManage
             FROM sessions s
             WHERE s.id = @SessionId
             """,
-            new { command.SessionId, command.TelegramUserId }, transaction);
+            new { command.SessionId, ExternalUserId = command.TelegramUserId.ToString() }, transaction);
 
         if (session == null)
         {
@@ -89,7 +90,7 @@ public sealed class CancelSessionHandler(
 
         var directRecipients = (await connection.QueryAsync<DirectNotificationRecipient>(
             """
-            SELECT p.telegram_id AS TelegramId,
+            SELECT p.external_user_id::BIGINT AS TelegramId,
                    p.display_name AS DisplayName
             FROM session_participants sp
             JOIN players p ON sp.player_id = p.id

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

@@ -77,16 +77,15 @@ public sealed class CreateSessionHandler(
         {
             await connection.ExecuteAsync(
                 """
-                INSERT INTO players (telegram_id, display_name, telegram_username, platform, external_user_id, external_username)
-                VALUES (@TgId, @Name, @Username, 'Telegram', @TgId::TEXT, @Username)
-                ON CONFLICT (telegram_id) DO UPDATE
+                INSERT INTO players (display_name, platform, external_user_id, external_username)
+                VALUES (@Name, 'Telegram', @ExternalId, @Username)
+                ON CONFLICT (platform, external_user_id)
+                WHERE platform IS NOT NULL AND external_user_id IS NOT NULL
+                DO UPDATE
                 SET display_name = EXCLUDED.display_name,
-                    telegram_username = EXCLUDED.telegram_username,
-                    platform = COALESCE(players.platform, 'Telegram'),
-                    external_user_id = COALESCE(players.external_user_id, EXCLUDED.telegram_id::TEXT),
-                    external_username = COALESCE(players.external_username, EXCLUDED.telegram_username);
+                    external_username = EXCLUDED.external_username;
                 """,
-                new { TgId = gmId, Name = gmName, Username = gmUsername },
+                new { ExternalId = gmId.ToString(), Name = gmName, Username = gmUsername },
                 transaction);
 
             var existingGroup = await connection.QuerySingleOrDefaultAsync<SessionCreationGroupAccessDto>(
@@ -97,12 +96,14 @@ public sealed class CreateSessionHandler(
                            FROM group_managers gm
                            JOIN players p ON p.id = gm.player_id
                            WHERE gm.group_id = g.id
-                             AND COALESCE(p.external_user_id, p.telegram_id::TEXT) = @GmId::TEXT
+                             AND p.platform = 'Telegram'
+                             AND p.external_user_id = @ExternalGmId
                        ) AS CanManage
                 FROM game_groups g
-                WHERE COALESCE(g.external_group_id, g.telegram_chat_id::TEXT) = @ChatId::TEXT
+                WHERE g.platform = 'Telegram'
+                  AND g.external_group_id = @ExternalChatId
                 """,
-                new { ChatId = chatId, GmId = gmId },
+                new { ExternalChatId = chatId.ToString(), ExternalGmId = gmId.ToString() },
                 transaction);
 
             Guid groupId;
@@ -110,11 +111,11 @@ public sealed class CreateSessionHandler(
             {
                 groupId = await connection.ExecuteScalarAsync<Guid>(
                     """
-                    INSERT INTO game_groups (telegram_chat_id, name, gm_telegram_id, platform, external_group_id)
-                    VALUES (@ChatId, @ChatName, @GmId, 'Telegram', @ChatId::TEXT)
+                    INSERT INTO game_groups (name, platform, external_group_id)
+                    VALUES (@ChatName, 'Telegram', @ExternalChatId)
                     RETURNING id;
                     """,
-                    new { ChatId = chatId, ChatName = chatTitle, GmId = gmId },
+                    new { ExternalChatId = chatId.ToString(), ChatName = chatTitle },
                     transaction);
 
                 await connection.ExecuteAsync(
@@ -122,10 +123,11 @@ public sealed class CreateSessionHandler(
                     INSERT INTO group_managers (group_id, player_id, role)
                     SELECT @GroupId, p.id, @OwnerRole
                     FROM players p
-                    WHERE COALESCE(p.external_user_id, p.telegram_id::TEXT) = @GmId::TEXT
+                    WHERE p.platform = 'Telegram'
+                      AND p.external_user_id = @ExternalGmId
                     ON CONFLICT (group_id, player_id) DO NOTHING
                     """,
-                    new { GroupId = groupId, GmId = gmId, OwnerRole = GroupManagerRoleExtensions.OwnerValue },
+                    new { GroupId = groupId, ExternalGmId = gmId.ToString(), OwnerRole = GroupManagerRoleExtensions.OwnerValue },
                     transaction);
             }
             else

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

@@ -41,13 +41,14 @@ public sealed class PromoteWaitlistedPlayerHandler(
                            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
+                             AND p.platform = 'Telegram'
+                             AND p.external_user_id = @ExternalUserId
                        ) AS CanManage
                 FROM sessions s
                 WHERE s.id = @SessionId
                 FOR UPDATE
                 """,
-                new { command.SessionId, command.TelegramUserId },
+                new { command.SessionId, ExternalUserId = command.TelegramUserId.ToString() },
                 transaction);
 
             if (session is null)
@@ -150,7 +151,7 @@ public sealed class PromoteWaitlistedPlayerHandler(
                 """
                 SELECT sp.session_id AS SessionId,
                        p.display_name AS DisplayName,
-                       p.telegram_username AS TelegramUsername,
+                       p.external_username AS TelegramUsername,
                        sp.registration_status AS RegistrationStatus
                 FROM session_participants sp
                 JOIN players p ON sp.player_id = p.id

src/GmRelay.Bot/Features/Sessions/ExportCalendar/ExportCalendarHandler.cs

@@ -24,11 +24,12 @@ public sealed class ExportCalendarHandler(
             @"SELECT s.id as Id, s.title as Title, s.scheduled_at as ScheduledAt"
             + " FROM sessions s"
             + " JOIN game_groups g ON s.group_id = g.id"
-            + " WHERE g.telegram_chat_id = @ChatId"
+            + " WHERE g.platform = 'Telegram'"
+            + " AND g.external_group_id = @ExternalChatId"
             + " AND s.status = @Planned"
             + " AND s.scheduled_at > NOW()"
             + " ORDER BY s.scheduled_at ASC",
-            new { ChatId = message.Chat.Id, Planned = SessionStatus.Planned });
+            new { ExternalChatId = message.Chat.Id.ToString(), Planned = SessionStatus.Planned });
 
         var sessionsList = sessions.ToList();
 
@@ -75,13 +76,13 @@ public sealed class ExportCalendarHandler(
             {
                 var token = Guid.NewGuid().ToString("N");
                 var groupId = await connection.QueryFirstOrDefaultAsync<Guid?>(
-                    @"SELECT id FROM game_groups WHERE telegram_chat_id = @ChatId",
-                    new { ChatId = message.Chat.Id });
+                    @"SELECT id FROM game_groups WHERE platform = 'Telegram' AND external_group_id = @ExternalChatId",
+                    new { ExternalChatId = message.Chat.Id.ToString() });
 
                 await connection.ExecuteAsync(
-                    @"INSERT INTO calendar_subscriptions (id, token, user_telegram_id, group_id, filter_type, created_at, expires_at)
-                      VALUES (gen_random_uuid(), @token, @userTelegramId, @groupId, @filterType, now(), NULL)",
-                    new { token, userTelegramId = senderId.Value, groupId, filterType = (int)CalendarSubscriptionFilter.SpecificGroup });
+                    @"INSERT INTO calendar_subscriptions (id, token, user_platform, user_external_id, group_id, filter_type, created_at, expires_at)
+                      VALUES (gen_random_uuid(), @token, 'Telegram', @userExternalId, @groupId, @filterType, now(), NULL)",
+                    new { token, userExternalId = senderId.Value.ToString(), groupId, filterType = (int)CalendarSubscriptionFilter.SpecificGroup });
 
                 subscriptionUrl = $"{baseUrl.TrimEnd('/')}/calendar/{token}.ics";
             }

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

@@ -44,12 +44,13 @@ public sealed class DeleteSessionHandler(
                        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
+                         AND p.platform = 'Telegram'
+                       AND p.external_user_id = @ExternalUserId
                    ) AS CanManage
             FROM sessions s
             WHERE s.id = @SessionId
             """,
-            new { command.SessionId, command.TelegramUserId }, transaction);
+            new { command.SessionId, ExternalUserId = command.TelegramUserId.ToString() }, transaction);
 
         if (session == null)
         {
@@ -109,18 +110,22 @@ public sealed class DeleteSessionHandler(
                          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.telegram_id = @TelegramUserId
+                           AND manager_player.platform = 'Telegram'
+                           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.telegram_chat_id = @ChatId AND s.status != @Cancelled AND s.scheduled_at > NOW()
+              WHERE g.platform = 'Telegram'
+                AND g.external_group_id = @ExternalChatId
+                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
             {
-                ChatId = command.ChatId,
-                command.TelegramUserId,
+                ExternalChatId = command.ChatId.ToString(),
+                ExternalUserId = command.TelegramUserId.ToString(),
                 Cancelled = SessionStatus.Cancelled,
                 Active = ParticipantRegistrationStatus.Active,
                 Waitlisted = ParticipantRegistrationStatus.Waitlisted

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

@@ -74,18 +74,22 @@ public sealed class ListSessionsHandler(
                          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.telegram_id = @TelegramUserId
+                           AND manager_player.platform = 'Telegram'
+                           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.telegram_chat_id = @ChatId AND s.status != @Cancelled AND s.scheduled_at > NOW()
+              WHERE g.platform = 'Telegram'
+                AND g.external_group_id = @ExternalChatId
+                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
             {
-                ChatId = message.Chat.Id,
-                TelegramUserId = message.From?.Id,
+                ExternalChatId = message.Chat.Id.ToString(),
+                ExternalUserId = message.From?.Id.ToString(),
                 Cancelled = SessionStatus.Cancelled,
                 Active = ParticipantRegistrationStatus.Active,
                 Waitlisted = ParticipantRegistrationStatus.Waitlisted

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

@@ -53,26 +53,28 @@ 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,
+                   g.external_group_id::BIGINT 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
             JOIN game_groups g ON g.id = s.group_id
-            WHERE rp.proposed_by = @GmId
+            WHERE rp.proposed_by_external_user_id = @ExternalGmId
               AND rp.status = 'AwaitingTime'
-              AND g.telegram_chat_id = @ChatId
+              AND g.platform = 'Telegram'
+              AND g.external_group_id = @ExternalChatId
               AND 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.telegram_id = @GmId
+                    AND manager_player.platform = 'Telegram'
+                    AND manager_player.external_user_id = @ExternalGmId
               )
             ORDER BY rp.created_at DESC
             LIMIT 1
             """,
-            new { GmId = gmTelegramId, ChatId = chatId });
+            new { ExternalGmId = gmTelegramId.ToString(), ExternalChatId = chatId.ToString() });
 
         if (proposal is null)
             return false;
@@ -92,8 +94,8 @@ public sealed class HandleRescheduleTimeInputHandler(
             """
             SELECT p.id AS PlayerId,
                    p.display_name AS DisplayName,
-                   p.telegram_username AS TelegramUsername,
-                   p.telegram_id AS TelegramId
+                   p.external_username AS TelegramUsername,
+                   p.external_user_id::BIGINT AS TelegramId
             FROM session_participants sp
             JOIN players p ON p.id = sp.player_id
             WHERE sp.session_id = @SessionId
@@ -363,7 +365,7 @@ public sealed class HandleRescheduleTimeInputHandler(
                 """
                 SELECT sp.session_id AS SessionId,
                        p.display_name AS DisplayName,
-                       p.telegram_username AS TelegramUsername,
+                       p.external_username AS TelegramUsername,
                        sp.registration_status AS RegistrationStatus
                 FROM session_participants sp
                 JOIN players p ON sp.player_id = p.id

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

@@ -58,11 +58,12 @@ public sealed class HandleRescheduleVoteHandler(
             FROM session_participants sp
             JOIN players p ON p.id = sp.player_id
             WHERE sp.session_id = @SessionId
-              AND p.telegram_id = @TelegramUserId
+              AND p.platform = 'Telegram'
+              AND p.external_user_id = @ExternalUserId
               AND sp.is_gm = false
               AND sp.registration_status = @Active
             """,
-            new { proposal.SessionId, command.TelegramUserId, Active = ParticipantRegistrationStatus.Active },
+            new { proposal.SessionId, ExternalUserId = command.TelegramUserId.ToString(), Active = ParticipantRegistrationStatus.Active },
             transaction);
 
         if (playerId is null)
@@ -91,8 +92,8 @@ public sealed class HandleRescheduleVoteHandler(
             """
             SELECT p.id AS PlayerId,
                    p.display_name AS DisplayName,
-                   p.telegram_username AS TelegramUsername,
-                   p.telegram_id AS TelegramId
+                   p.external_username AS TelegramUsername,
+                   p.external_user_id::BIGINT AS TelegramId
             FROM session_participants sp
             JOIN players p ON p.id = sp.player_id
             WHERE sp.session_id = @SessionId
@@ -120,7 +121,7 @@ public sealed class HandleRescheduleVoteHandler(
             SELECT rov.option_id AS OptionId,
                    p.id AS PlayerId,
                    p.display_name AS DisplayName,
-                   p.telegram_username AS TelegramUsername
+                   p.external_username AS TelegramUsername
             FROM reschedule_option_votes rov
             JOIN players p ON p.id = rov.player_id
             WHERE rov.proposal_id = @ProposalId

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

@@ -45,12 +45,13 @@ public sealed class InitiateRescheduleHandler(
                        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
+                         AND p.platform = 'Telegram'
+                         AND p.external_user_id = @ExternalUserId
                    ) AS CanManage
             FROM sessions s
             WHERE s.id = @SessionId AND s.status != @Cancelled
             """,
-            new { command.SessionId, command.TelegramUserId, Cancelled = SessionStatus.Cancelled });
+            new { command.SessionId, ExternalUserId = command.TelegramUserId.ToString(), Cancelled = SessionStatus.Cancelled });
 
         if (session is null)
         {
@@ -83,10 +84,10 @@ public sealed class InitiateRescheduleHandler(
         // 3. Create proposal in AwaitingTime status
         await connection.ExecuteAsync(
             """
-            INSERT INTO reschedule_proposals (session_id, proposed_by, source_platform, status)
-            VALUES (@SessionId, @GmId, 'Telegram', 'AwaitingTime')
+            INSERT INTO reschedule_proposals (session_id, proposed_by_external_user_id, source_platform, status)
+            VALUES (@SessionId, @ProposedBy, 'Telegram', 'AwaitingTime')
             """,
-            new { command.SessionId, GmId = command.TelegramUserId });
+            new { command.SessionId, ProposedBy = command.TelegramUserId.ToString() });
 
         logger.LogInformation("Reschedule initiated for session {SessionId} by GM {GmId}", command.SessionId, command.TelegramUserId);
 

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

@@ -79,7 +79,7 @@ public sealed class RescheduleVotingDeadlineService(
             """
             SELECT rp.vote_message_id AS VoteMessageId,
                    s.batch_message_id AS BatchMessageId,
-                   g.telegram_chat_id AS TelegramChatId,
+                   g.external_group_id::BIGINT AS TelegramChatId,
                    s.thread_id AS ThreadId
             FROM reschedule_proposals rp
             JOIN sessions s ON s.id = rp.session_id
@@ -169,7 +169,7 @@ public sealed class RescheduleVotingDeadlineService(
                 """
                 SELECT sp.session_id AS SessionId,
                        p.display_name AS DisplayName,
-                       p.telegram_username AS TelegramUsername,
+                       p.external_username AS TelegramUsername,
                        sp.registration_status AS RegistrationStatus
                 FROM session_participants sp
                 JOIN players p ON sp.player_id = p.id

src/GmRelay.Bot/Migrations/V020__player_identity_links.sql

@@ -0,0 +1,37 @@
+-- =============================================================
+-- V020: Player identity linking for unified multi-platform accounts
+-- =============================================================
+-- Scope: Allow linking multiple platform identities (Telegram, Discord)
+-- to a single "primary" player account. All group/session permissions
+-- resolve through the effective (primary) player id.
+-- =============================================================
+
+-- player_links: secondary player → primary player (1:1 on secondary)
+CREATE TABLE player_links (
+    id                    UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    primary_player_id     UUID NOT NULL REFERENCES players(id) ON DELETE CASCADE,
+    secondary_player_id   UUID NOT NULL UNIQUE REFERENCES players(id) ON DELETE CASCADE,
+    linked_at             TIMESTAMPTZ NOT NULL DEFAULT now(),
+    linked_by_player_id   UUID REFERENCES players(id) ON DELETE SET NULL,
+    -- Prevent self-linking at the DB level
+    CONSTRAINT no_self_link CHECK (primary_player_id <> secondary_player_id)
+);
+
+CREATE INDEX ix_player_links_primary_player_id
+    ON player_links(primary_player_id);
+
+-- identity_audit_log: security-sensitive link/unlink actions
+CREATE TABLE identity_audit_log (
+    id                      UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    player_id               UUID NOT NULL REFERENCES players(id) ON DELETE CASCADE,
+    action                  VARCHAR(50) NOT NULL,   -- 'link', 'unlink', 'link_attempt_conflict'
+    target_platform         VARCHAR(50),
+    target_external_user_id VARCHAR(255),
+    performed_at            TIMESTAMPTZ NOT NULL DEFAULT now(),
+    performed_by_player_id  UUID REFERENCES players(id) ON DELETE SET NULL
+);
+
+CREATE INDEX ix_identity_audit_log_player_id
+    ON identity_audit_log(player_id);
+CREATE INDEX ix_identity_audit_log_performed_at
+    ON identity_audit_log(performed_at DESC);

src/GmRelay.Bot/Migrations/V021__add_avatar_url.sql

@@ -0,0 +1,8 @@
+-- =============================================================
+-- V021: Add avatar_url column to players table
+-- =============================================================
+-- Scope: Support storing avatar URLs for Discord and other platforms.
+-- =============================================================
+
+ALTER TABLE players
+    ADD COLUMN avatar_url VARCHAR(500);

src/GmRelay.Bot/Migrations/V022__fix_discord_telegram_links.sql

@@ -0,0 +1,16 @@
+-- =============================================================
+-- V022: Fix incorrectly oriented player_links for Discord↔Telegram
+-- =============================================================
+-- Scope: Reverse player_links where Discord was incorrectly made primary
+-- and Telegram secondary. Telegram (with historical group/session data)
+-- must always be the primary account.
+-- =============================================================
+
+UPDATE player_links pl
+SET primary_player_id   = pl.secondary_player_id,
+    secondary_player_id = pl.primary_player_id
+FROM players p1, players p2
+WHERE pl.primary_player_id = p1.id
+  AND pl.secondary_player_id = p2.id
+  AND p1.platform = 'Discord'
+  AND p2.platform = 'Telegram';

src/GmRelay.Bot/Migrations/V023__game_groups_telegram_chat_id_nullable.sql

@@ -0,0 +1,14 @@
+-- =============================================================
+-- V023: Make legacy Telegram columns nullable for multi-platform
+-- =============================================================
+-- Scope: Allow Discord (and future platforms) to create players
+-- and game_groups without legacy telegram_* values.
+-- Existing Telegram data was backfilled in V016.
+-- =============================================================
+
+ALTER TABLE game_groups
+    ALTER COLUMN telegram_chat_id DROP NOT NULL,
+    ALTER COLUMN gm_telegram_id DROP NOT NULL;
+
+ALTER TABLE players
+    ALTER COLUMN telegram_id DROP NOT NULL;

src/GmRelay.Bot/Migrations/V024__deprecate_telegram_columns.sql

@@ -0,0 +1,41 @@
+-- =============================================================
+-- V024: Deprecate legacy Telegram-specific columns
+-- =============================================================
+-- Scope: Complete platform migration by backfilling any remaining
+-- external_* gaps and officially deprecating telegram_* columns.
+-- No columns are dropped — rollback-safe.
+-- =============================================================
+
+-- 1. Backfill players platform identity (safeguard for any rows missed in V016)
+UPDATE players
+   SET platform          = 'Telegram',
+       external_user_id  = telegram_id::TEXT,
+       external_username = telegram_username
+ WHERE platform IS NULL;
+
+-- 2. Backfill game_groups platform identity (safeguard for any rows missed in V016)
+UPDATE game_groups
+   SET platform          = 'Telegram',
+       external_group_id = telegram_chat_id::TEXT
+ WHERE platform IS NULL;
+
+-- 3. Add platform identity to calendar_subscriptions
+ALTER TABLE calendar_subscriptions
+    ADD COLUMN user_platform   VARCHAR(50),
+    ADD COLUMN user_external_id VARCHAR(255);
+
+UPDATE calendar_subscriptions
+   SET user_external_id = user_telegram_id::TEXT,
+       user_platform    = 'Telegram'
+ WHERE user_platform IS NULL;
+
+-- 4. Migrate calendar subscription index
+DROP INDEX IF EXISTS ix_calendar_subscriptions_user_telegram_id;
+CREATE INDEX ix_calendar_subscriptions_user_external_id ON calendar_subscriptions (user_external_id);
+
+-- 5. Deprecation comments on legacy columns
+COMMENT ON COLUMN players.telegram_id         IS 'DEPRECATED: use platform + external_user_id';
+COMMENT ON COLUMN players.telegram_username   IS 'DEPRECATED: use external_username';
+COMMENT ON COLUMN game_groups.telegram_chat_id IS 'DEPRECATED: use platform + external_group_id';
+COMMENT ON COLUMN game_groups.gm_telegram_id   IS 'DEPRECATED: group ownership is tracked in group_managers';
+COMMENT ON COLUMN calendar_subscriptions.user_telegram_id IS 'DEPRECATED: use user_platform + user_external_id';

src/GmRelay.Bot/Migrations/V025__reschedule_proposals_telegram_external.sql

@@ -0,0 +1,11 @@
+-- =============================================================
+-- V025: Backfill proposed_by_external_user_id for Telegram proposals
+-- =============================================================
+-- Scope: Ensure all reschedule_proposals have proposed_by_external_user_id
+-- populated so that InitiateRescheduleHandler can stop writing proposed_by.
+-- =============================================================
+
+UPDATE reschedule_proposals
+   SET proposed_by_external_user_id = proposed_by::TEXT
+ WHERE proposed_by_external_user_id IS NULL
+   AND proposed_by IS NOT NULL;

src/GmRelay.DiscordBot/Features/Sessions/DiscordDeleteSessionHandler.cs

@@ -0,0 +1,84 @@
+using Dapper;
+using GmRelay.DiscordBot.Infrastructure.Discord;
+using GmRelay.Shared.Rendering;
+using Npgsql;
+
+namespace GmRelay.DiscordBot.Features.Sessions;
+
+public sealed record DiscordDeleteSessionResult(
+    string ReplyText,
+    SessionBatchViewModel? UpdatedView,
+    string? EmptyMessage = null);
+
+public sealed class DiscordDeleteSessionHandler(
+    NpgsqlDataSource dataSource,
+    DiscordPermissionChecker permissionChecker,
+    DiscordListSessionsHandler listSessionsHandler,
+    ILogger<DiscordDeleteSessionHandler> logger)
+{
+    public async Task<DiscordDeleteSessionResult> HandleAsync(
+        string guildId,
+        string channelId,
+        ulong userId,
+        ulong resolvedPermissions,
+        ulong guildOwnerId,
+        Guid sessionId,
+        CancellationToken cancellationToken)
+    {
+        await using var connection = await dataSource.OpenConnectionAsync(cancellationToken);
+
+        var dbManagerUserIds = await connection.QueryAsync<ulong>(
+            @"SELECT CAST(p.external_user_id AS BIGINT)
+              FROM group_managers gm
+              JOIN players p ON p.id = gm.player_id
+              JOIN game_groups g ON g.id = gm.group_id
+              WHERE g.platform = 'Discord' AND g.external_group_id = @GuildId",
+            new { GuildId = guildId });
+
+        if (!permissionChecker.CanManageSchedule(guildOwnerId, userId, dbManagerUserIds, resolvedPermissions))
+        {
+            return new DiscordDeleteSessionResult(
+                "Только owner, администратор или manager могут удалять сессии.",
+                UpdatedView: null);
+        }
+
+        await using var transaction = await connection.BeginTransactionAsync(cancellationToken);
+        var deletedRows = await connection.ExecuteAsync(
+            """
+            DELETE FROM sessions s
+            USING game_groups g
+            WHERE s.group_id = g.id
+              AND s.id = @SessionId
+              AND g.platform = 'Discord'
+              AND g.external_group_id = @GuildId
+            """,
+            new { SessionId = sessionId, GuildId = guildId },
+            transaction);
+
+        await transaction.CommitAsync(cancellationToken);
+
+        if (deletedRows == 0)
+        {
+            return new DiscordDeleteSessionResult(
+                "Сессия не найдена или уже удалена.",
+                UpdatedView: null);
+        }
+
+        logger.LogInformation("Deleted Discord session {SessionId} in guild {GuildId}", sessionId, guildId);
+
+        var updatedView = await listSessionsHandler.BuildScheduleAsync(
+            guildId,
+            channelId,
+            userId,
+            resolvedPermissions,
+            guildOwnerId,
+            cancellationToken);
+
+        return updatedView is null
+            ? new DiscordDeleteSessionResult(
+                "Сессия удалена.",
+                UpdatedView: null,
+                EmptyMessage: "В этом сервере нет предстоящих игр.")
+            : new DiscordDeleteSessionResult("Сессия удалена.", updatedView);
+    }
+}

src/GmRelay.DiscordBot/Features/Sessions/DiscordListSessionsCommand.cs

@@ -1,9 +1,9 @@
+using NetCord;
 using NetCord.Rest;
 using NetCord.Services.ApplicationCommands;
 
 namespace GmRelay.DiscordBot.Features.Sessions;
 
-[SlashCommand("listsessions", "Show upcoming game sessions in this server")]
 public class DiscordListSessionsCommand : ApplicationCommandModule<SlashCommandContext>
 {
     private readonly DiscordListSessionsHandler _handler;
@@ -13,13 +13,23 @@ public class DiscordListSessionsCommand : ApplicationCommandModule<SlashCommandC
         _handler = handler;
     }
 
+    [SlashCommand("listsessions", "Show upcoming game sessions in this server")]
     public async Task ExecuteAsync()
     {
-        var guildId = Context.Guild?.Id.ToString()
+        var guildId = Context.Interaction.GuildId?.ToString()
             ?? throw new InvalidOperationException("This command can only be used in a guild.");
         var channelId = Context.Channel.Id.ToString();
+        var member = Context.User as GuildInteractionUser;
+        var resolvedPermissions = member is null ? 0UL : (ulong)member.Permissions;
+        var guildOwnerId = 0UL;
 
-        var view = await _handler.BuildScheduleAsync(guildId, channelId, CancellationToken.None);
+        var view = await _handler.BuildScheduleAsync(
+            guildId,
+            channelId,
+            Context.User.Id,
+            resolvedPermissions,
+            guildOwnerId,
+            CancellationToken.None);
 
         if (view is null)
         {

src/GmRelay.DiscordBot/Features/Sessions/DiscordListSessionsHandler.cs

@@ -1,4 +1,5 @@
 using Dapper;
+using GmRelay.DiscordBot.Infrastructure.Discord;
 using GmRelay.Shared.Domain;
 using GmRelay.Shared.Rendering;
 using Npgsql;
@@ -9,11 +10,22 @@ internal sealed record DiscordSessionListItemDto(
     Guid Id, string Title, DateTime ScheduledAt, string Status, int? MaxPlayers,
     int PlayerCount, int WaitlistCount);
 
-public sealed class DiscordListSessionsHandler(NpgsqlDataSource dataSource)
+public sealed class DiscordListSessionsHandler(
+    NpgsqlDataSource dataSource,
+    DiscordPermissionChecker permissionChecker)
 {
+    public Task<SessionBatchViewModel?> BuildScheduleAsync(
+        string guildId,
+        string channelId,
+        CancellationToken cancellationToken) =>
+        BuildScheduleAsync(guildId, channelId, 0, 0, 0, cancellationToken);
+
     public async Task<SessionBatchViewModel?> BuildScheduleAsync(
         string guildId,
         string channelId,
+        ulong userId,
+        ulong resolvedPermissions,
+        ulong guildOwnerId,
         CancellationToken cancellationToken)
     {
         await using var connection = await dataSource.OpenConnectionAsync(cancellationToken);
@@ -21,15 +33,15 @@ public sealed class DiscordListSessionsHandler(NpgsqlDataSource dataSource)
         var sessions = await connection.QueryAsync<DiscordSessionListItemDto>(
             @"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
+                     COUNT(sp.id) FILTER (WHERE sp.is_gm = false AND sp.registration_status = @Active)::int as PlayerCount,
+                     COUNT(sp.id) FILTER (WHERE sp.is_gm = false AND sp.registration_status = @Waitlisted)::int as WaitlistCount
               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 = 'Discord'
                 AND g.external_group_id = @GuildId
                 AND s.status != @Cancelled
-                AND s.scheduled_at > NOW()
+                AND s.scheduled_at > now() - interval '4 hours'
               GROUP BY s.id, s.title, s.scheduled_at, s.status, s.max_players
               ORDER BY s.scheduled_at ASC",
             new
@@ -44,11 +56,25 @@ public sealed class DiscordListSessionsHandler(NpgsqlDataSource dataSource)
         if (sessionList.Count == 0)
             return null;
 
+        var dbManagerUserIds = await connection.QueryAsync<ulong>(
+            @"SELECT CAST(p.external_user_id AS BIGINT)
+              FROM group_managers gm
+              JOIN players p ON p.id = gm.player_id
+              JOIN game_groups g ON g.id = gm.group_id
+              WHERE g.platform = 'Discord' AND g.external_group_id = @GuildId",
+            new { GuildId = guildId });
+
+        var canManage = permissionChecker.CanManageSchedule(
+            guildOwnerId,
+            userId,
+            dbManagerUserIds,
+            resolvedPermissions);
+
         var sessionIds = sessionList.Select(s => s.Id).ToList();
         var participants = await connection.QueryAsync<ParticipantBatchDto>(
             @"SELECT sp.session_id as SessionId,
                      p.display_name as DisplayName,
-                     COALESCE(p.external_username, p.telegram_username) as TelegramUsername,
+                     p.external_username as TelegramUsername,
                      sp.registration_status as RegistrationStatus
               FROM session_participants sp
               JOIN players p ON p.id = sp.player_id
@@ -60,6 +86,25 @@ public sealed class DiscordListSessionsHandler(NpgsqlDataSource dataSource)
         var batchDtos = sessionList.Select(s => new SessionBatchDto(
             s.Id, s.ScheduledAt, s.Status, s.MaxPlayers, "")).ToList();
 
-        return SessionBatchViewBuilder.Build(firstTitle, batchDtos, participants.ToList());
+        var view = SessionBatchViewBuilder.Build(firstTitle, batchDtos, participants.ToList());
+        return canManage ? AddManagerActions(view) : view;
     }
+
+    internal static SessionBatchViewModel AddManagerActions(SessionBatchViewModel view) =>
+        view with
+        {
+            Sessions = view.Sessions
+                .Select(session =>
+                {
+                    if (SessionStatus.IsCancelled(session.Status))
+                        return session;
+
+                    var actions = session.AvailableActions
+                        .Concat([new AvailableAction("delete_session", $"Удалить {session.ScheduledAt.FormatMoscowShort()}", session.SessionId)])
+                        .ToList();
+
+                    return session with { AvailableActions = actions };
+                })
+                .ToList()
+        };
 }

src/GmRelay.DiscordBot/Features/Sessions/DiscordNewSessionCommand.cs

@@ -1,10 +1,10 @@
-using GmRelay.DiscordBot.Rendering;
+using GmRelay.DiscordBot.Rendering;
+using NetCord;
 using NetCord.Rest;
 using NetCord.Services.ApplicationCommands;
 
 namespace GmRelay.DiscordBot.Features.Sessions;
 
-[SlashCommand("newsession", "Create a new game session")]
 public class DiscordNewSessionCommand : ApplicationCommandModule<SlashCommandContext>
 {
     private readonly DiscordNewSessionHandler _handler;
@@ -16,15 +16,54 @@ public class DiscordNewSessionCommand : ApplicationCommandModule<SlashCommandCon
         _logger = logger;
     }
 
+    [SlashCommand("newsession", "Create a new game session")]
     public async Task ExecuteAsync(
         [SlashCommandParameter(Name = "title", Description = "Game title")] string title,
         [SlashCommandParameter(Name = "time", Description = "Session time (YYYY-MM-DD HH:mm or DD.MM.YYYY HH:mm)")] string time,
         [SlashCommandParameter(Name = "seats", Description = "Maximum number of players")] long? seats = null,
         [SlashCommandParameter(Name = "link", Description = "Join link")] string? link = null)
     {
-        var guild = Context.Guild
+        _logger.LogInformation(
+            "newsession called by user {UserId} ({UserType}) in guild {GuildId}, channel {ChannelId}",
+            Context.User.Id,
+            Context.User.GetType().Name,
+            Context.Interaction.GuildId,
+            Context.Channel?.Id);
+
+        var guildId = Context.Interaction.GuildId
             ?? throw new InvalidOperationException("This command can only be used in a guild.");
 
+        var member = Context.User as GuildInteractionUser;
+        if (member is null)
+        {
+            _logger.LogError("Context.User is not GuildInteractionUser. Actual type: {ActualType}", Context.User.GetType().Name);
+            throw new InvalidOperationException("Guild member data not available in interaction.");
+        }
+
+        var resolvedPermissions = (ulong)member.Permissions;
+        _logger.LogInformation("Resolved permissions for user {UserId}: {Permissions}", Context.User.Id, resolvedPermissions);
+
+        ulong guildOwnerId = 0;
+        var guildName = guildId.ToString();
+        try
+        {
+            var guild = await Context.Client.Rest.GetGuildAsync(guildId);
+            guildOwnerId = guild.OwnerId;
+            guildName = guild.Name;
+            _logger.LogInformation("Guild owner id: {OwnerId}", guildOwnerId);
+        }
+        catch (RestException ex) when (ex.StatusCode == System.Net.HttpStatusCode.NotFound)
+        {
+            _logger.LogWarning(
+                ex,
+                "Bot is not a REST member of guild {GuildId}; using resolved permissions from interaction payload",
+                guildId);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Unexpected error fetching guild {GuildId}", guildId);
+        }
+
         var timeResult = DiscordNewSessionHandler.ParseTimeInput(time);
         if (!timeResult.IsSuccess)
         {
@@ -33,55 +72,57 @@ public class DiscordNewSessionCommand : ApplicationCommandModule<SlashCommandCon
             return;
         }
 
-        var resolvedPermissions = GetResolvedPermissions(guild, Context.User.Id);
+        // Defer the response to avoid Discord 3-second interaction timeout
+        await Context.Interaction.SendResponseAsync(InteractionCallback.DeferredMessage());
 
         try
         {
+            _logger.LogInformation("Creating session for guild {GuildId}, user {UserId}", guildId, Context.User.Id);
+
             var view = await _handler.HandleAsync(
-                guildId: guild.Id.ToString(),
-                channelId: Context.Channel.Id.ToString(),
+                guildId: guildId.ToString(),
+                channelId: Context.Channel!.Id.ToString(),
+                groupName: guildName,
                 userId: Context.User.Id,
                 userDisplayName: Context.User.GlobalName ?? Context.User.Username,
                 resolvedPermissions: resolvedPermissions,
-                guildOwnerId: guild.OwnerId,
+                guildOwnerId: guildOwnerId,
                 title: title,
                 scheduledAt: timeResult.Value,
                 maxPlayers: seats is null ? null : (int)seats.Value,
                 joinLink: link,
                 CancellationToken.None);
 
+            _logger.LogInformation("Session created successfully. Building render.");
+
             var (embeds, actionRows) = DiscordSessionBatchRenderer.Render(view);
-            await Context.Interaction.SendResponseAsync(
-                InteractionCallback.Message(new InteractionMessageProperties()
-                    .WithContent(":white_check_mark: **Session created successfully!**")
-                    .WithEmbeds(embeds)
-                    .WithComponents(actionRows)));
+
+            _logger.LogInformation("Sending success response.");
+
+            await Context.Interaction.ModifyResponseAsync(message =>
+            {
+                message.Content = ":white_check_mark: **Session created successfully!**";
+                message.Embeds = embeds;
+                message.Components = actionRows;
+            });
+
+            _logger.LogInformation("Success response sent.");
         }
         catch (UnauthorizedAccessException ex)
         {
-            await Context.Interaction.SendResponseAsync(
-                InteractionCallback.Message($":no_entry: {ex.Message}"));
+            _logger.LogWarning(ex, "Unauthorized session creation attempt by user {UserId}", Context.User.Id);
+            await Context.Interaction.ModifyResponseAsync(message =>
+            {
+                message.Content = $":no_entry: {ex.Message}";
+            });
         }
         catch (Exception ex)
         {
-            _logger.LogError(ex, "Failed to create session for user {UserId} in guild {GuildId}", Context.User.Id, guild.Id);
-            await Context.Interaction.SendResponseAsync(
-                InteractionCallback.Message(":boom: An error occurred while creating the session."));
+            _logger.LogError(ex, "Failed to create session for user {UserId} in guild {GuildId}", Context.User.Id, guildId);
+            await Context.Interaction.ModifyResponseAsync(message =>
+            {
+                message.Content = ":boom: An error occurred while creating the session.";
+            });
         }
     }
-
-    private static ulong GetResolvedPermissions(NetCord.Gateway.Guild guild, ulong userId)
-    {
-        if (!guild.Users.TryGetValue(userId, out var guildUser))
-            return 0;
-
-        ulong resolved = 0;
-        foreach (var roleId in guildUser.RoleIds)
-        {
-            if (guild.Roles.TryGetValue(roleId, out var role))
-                resolved |= (ulong)role.Permissions;
-        }
-
-        return resolved;
-    }
 }

src/GmRelay.DiscordBot/Features/Sessions/DiscordNewSessionHandler.cs

@@ -1,9 +1,9 @@
 using Dapper;
 using GmRelay.DiscordBot.Infrastructure.Discord;
 using GmRelay.Shared.Domain;
-using GmRelay.Shared.Platform;
 using GmRelay.Shared.Rendering;
 using Npgsql;
+using System.Globalization;
 
 namespace GmRelay.DiscordBot.Features.Sessions;
 
@@ -12,35 +12,40 @@ public sealed record TimeParseResult(bool IsSuccess, DateTimeOffset Value, strin
 public sealed class DiscordNewSessionHandler(
     NpgsqlDataSource dataSource,
     DiscordPermissionChecker permissionChecker,
-    IPlatformMessenger messenger,
     ILogger<DiscordNewSessionHandler> logger)
 {
+    private static readonly TimeSpan MoscowOffset = TimeSpan.FromHours(3);
+
     public static TimeParseResult ParseTimeInput(string input)
     {
-        if (DateTimeOffset.TryParseExact(
-            input.Trim(),
+        var trimmed = input.Trim();
+
+        if (DateTime.TryParseExact(
+            trimmed,
             "yyyy-MM-dd HH:mm",
-            System.Globalization.CultureInfo.InvariantCulture,
-            System.Globalization.DateTimeStyles.AssumeUniversal,
-            out var result))
+            CultureInfo.InvariantCulture,
+            DateTimeStyles.None,
+            out var dt1))
         {
-            if (result < DateTimeOffset.UtcNow)
+            var offset = new DateTimeOffset(dt1, MoscowOffset).ToUniversalTime();
+            if (offset < DateTimeOffset.UtcNow)
                 return new TimeParseResult(false, default, "Дата находится в прошлом.");
 
-            return new TimeParseResult(true, result.ToUniversalTime(), null);
+            return new TimeParseResult(true, offset, null);
         }
 
-        if (DateTimeOffset.TryParseExact(
-            input.Trim(),
+        if (DateTime.TryParseExact(
+            trimmed,
             "dd.MM.yyyy HH:mm",
-            System.Globalization.CultureInfo.InvariantCulture,
-            System.Globalization.DateTimeStyles.AssumeUniversal,
-            out var altResult))
+            CultureInfo.InvariantCulture,
+            DateTimeStyles.None,
+            out var dt2))
         {
-            if (altResult < DateTimeOffset.UtcNow)
+            var offset = new DateTimeOffset(dt2, MoscowOffset).ToUniversalTime();
+            if (offset < DateTimeOffset.UtcNow)
                 return new TimeParseResult(false, default, "Дата находится в прошлом.");
 
-            return new TimeParseResult(true, altResult.ToUniversalTime(), null);
+            return new TimeParseResult(true, offset, null);
         }
 
         return new TimeParseResult(false, default, "Некорректный формат даты. Используйте YYYY-MM-DD HH:mm или DD.MM.YYYY HH:mm");
@@ -49,6 +54,7 @@ public sealed class DiscordNewSessionHandler(
     public async Task<SessionBatchViewModel> HandleAsync(
         string guildId,
         string channelId,
+        string groupName,
         ulong userId,
         string userDisplayName,
         ulong resolvedPermissions,
@@ -60,6 +66,9 @@ public sealed class DiscordNewSessionHandler(
         CancellationToken cancellationToken)
     {
         await using var connection = await dataSource.OpenConnectionAsync(cancellationToken);
+        var displayGroupName = string.IsNullOrWhiteSpace(groupName) || string.Equals(groupName, guildId, StringComparison.Ordinal)
+            ? title
+            : groupName.Trim();
 
         var dbManagerUserIds = await connection.QueryAsync<ulong>(
             @"SELECT CAST(p.external_user_id AS BIGINT)
@@ -75,6 +84,7 @@ public sealed class DiscordNewSessionHandler(
         }
 
         await using var transaction = await connection.BeginTransactionAsync(cancellationToken);
+        var transactionCommitted = false;
         try
         {
             await connection.ExecuteAsync(
@@ -89,13 +99,13 @@ public sealed class DiscordNewSessionHandler(
 
             var groupId = await connection.ExecuteScalarAsync<Guid>(
                 @"INSERT INTO game_groups (name, platform, external_group_id, external_channel_id)
-                  VALUES (@GuildId, 'Discord', @GuildId, @ChannelId)
+                  VALUES (@GroupName, 'Discord', @GuildId, @ChannelId)
                   ON CONFLICT (platform, external_group_id)
                   WHERE platform IS NOT NULL AND external_group_id IS NOT NULL
                   DO UPDATE SET name = EXCLUDED.name,
                                 external_channel_id = COALESCE(EXCLUDED.external_channel_id, game_groups.external_channel_id)
                   RETURNING id",
-                new { GuildId = guildId, ChannelId = channelId },
+                new { GroupName = displayGroupName, GuildId = guildId, ChannelId = channelId },
                 transaction);
 
             await connection.ExecuteAsync(
@@ -125,23 +135,19 @@ public sealed class DiscordNewSessionHandler(
                 transaction);
 
             await transaction.CommitAsync(cancellationToken);
+            transactionCommitted = true;
             logger.LogInformation("Created session {SessionId} in guild {GuildId}", sessionId, guildId);
 
             var sessions = new[] { new SessionBatchDto(sessionId, scheduledAt.UtcDateTime, SessionStatus.Planned, maxPlayers, joinLink ?? string.Empty) };
-            var view = SessionBatchViewBuilder.Build(title, sessions, Array.Empty<ParticipantBatchDto>());
-
-            await messenger.SendScheduleAsync(
-                new PlatformScheduleMessage(
-                    new PlatformGroup(PlatformKind.Discord, guildId, guildId, channelId),
-                    view,
-                    null),
-                cancellationToken);
-
-            return view;
+            return SessionBatchViewBuilder.Build(title, sessions, Array.Empty<ParticipantBatchDto>());
         }
         catch
         {
-            await transaction.RollbackAsync(cancellationToken);
+            if (!transactionCommitted)
+            {
+                await transaction.RollbackAsync(cancellationToken);
+            }
+
             throw;
         }
     }

src/GmRelay.DiscordBot/Features/Sessions/DiscordRescheduleCommand.cs

@@ -1,9 +1,9 @@
 namespace GmRelay.DiscordBot.Features.Sessions;
 
+using NetCord;
 using NetCord.Rest;
 using NetCord.Services.ApplicationCommands;
 
-[SlashCommand("reschedule", "Initiate reschedule voting for a session")]
 public class DiscordRescheduleCommand : ApplicationCommandModule<SlashCommandContext>
 {
     private readonly DiscordRescheduleHandler _handler;
@@ -15,6 +15,7 @@ public class DiscordRescheduleCommand : ApplicationCommandModule<SlashCommandCon
         _logger = logger;
     }
 
+    [SlashCommand("reschedule", "Initiate reschedule voting for a session")]
     public async Task ExecuteAsync(
         [SlashCommandParameter(Name = "session", Description = "Session ID to reschedule")] string sessionIdText,
         [SlashCommandParameter(Name = "option1", Description = "First time option (YYYY-MM-DD HH:mm)")] string option1,
@@ -22,9 +23,44 @@ public class DiscordRescheduleCommand : ApplicationCommandModule<SlashCommandCon
         [SlashCommandParameter(Name = "option3", Description = "Third time option (optional)")] string? option3 = null,
         [SlashCommandParameter(Name = "deadline", Description = "Voting deadline (YYYY-MM-DD HH:mm)")] string deadline = "")
     {
-        var guild = Context.Guild
+        _logger.LogInformation(
+            "reschedule called by user {UserId} ({UserType}) in guild {GuildId}",
+            Context.User.Id,
+            Context.User.GetType().Name,
+            Context.Interaction.GuildId);
+
+        var guildId = Context.Interaction.GuildId
             ?? throw new InvalidOperationException("This command can only be used in a guild.");
 
+        var member = Context.User as GuildInteractionUser;
+        if (member is null)
+        {
+            _logger.LogError("Context.User is not GuildInteractionUser. Actual type: {ActualType}", Context.User.GetType().Name);
+            throw new InvalidOperationException("Guild member data not available in interaction.");
+        }
+
+        var resolvedPermissions = (ulong)member.Permissions;
+        _logger.LogInformation("Resolved permissions for user {UserId}: {Permissions}", Context.User.Id, resolvedPermissions);
+
+        ulong guildOwnerId = 0;
+        try
+        {
+            var guild = await Context.Client.Rest.GetGuildAsync(guildId);
+            guildOwnerId = guild.OwnerId;
+            _logger.LogInformation("Guild owner id: {OwnerId}", guildOwnerId);
+        }
+        catch (RestException ex) when (ex.StatusCode == System.Net.HttpStatusCode.NotFound)
+        {
+            _logger.LogWarning(
+                ex,
+                "Bot is not a REST member of guild {GuildId}; using resolved permissions from interaction payload",
+                guildId);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Unexpected error fetching guild {GuildId}", guildId);
+        }
+
         if (!Guid.TryParse(sessionIdText, out var sessionId))
         {
             await Context.Interaction.SendResponseAsync(
@@ -64,54 +100,55 @@ public class DiscordRescheduleCommand : ApplicationCommandModule<SlashCommandCon
             return;
         }
 
-        var resolvedPermissions = GetResolvedPermissions(guild, Context.User.Id);
+        // Defer the response to avoid Discord 3-second interaction timeout
+        await Context.Interaction.SendResponseAsync(InteractionCallback.DeferredMessage());
 
         try
         {
+            _logger.LogInformation("Initiating reschedule for session {SessionId} in guild {GuildId}", sessionId, guildId);
+
             var result = await _handler.HandleAsync(
-                guildId: guild.Id.ToString(),
-                channelId: Context.Channel.Id.ToString(),
+                guildId: guildId.ToString(),
+                channelId: Context.Channel!.Id.ToString(),
                 userId: Context.User.Id,
                 userDisplayName: Context.User.GlobalName ?? Context.User.Username,
                 resolvedPermissions: resolvedPermissions,
-                guildOwnerId: guild.OwnerId,
+                guildOwnerId: guildOwnerId,
                 sessionId: sessionId,
                 options: parsedOptions,
                 deadline: deadlineResult.Value,
                 CancellationToken.None);
 
-            await Context.Interaction.SendResponseAsync(
-                InteractionCallback.Message(
-                    $"🗳 Голосование за перенос запущено! Дедлайн: {deadlineResult.Value:yyyy-MM-dd HH:mm} UTC."));
+            _logger.LogInformation("Reschedule voting started for session {SessionId}, proposal {ProposalId}", sessionId, result.ProposalId);
+
+            await Context.Interaction.ModifyResponseAsync(message =>
+            {
+                message.Content = $"🗳 Голосование за перенос запущено! Дедлайн: {deadlineResult.Value:yyyy-MM-dd HH:mm} UTC.";
+            });
         }
         catch (UnauthorizedAccessException ex)
         {
-            await Context.Interaction.SendResponseAsync(
-                InteractionCallback.Message($":no_entry: {ex.Message}"));
+            _logger.LogWarning(ex, "Unauthorized reschedule attempt by user {UserId}", Context.User.Id);
+            await Context.Interaction.ModifyResponseAsync(message =>
+            {
+                message.Content = $":no_entry: {ex.Message}";
+            });
         }
         catch (InvalidOperationException ex)
         {
-            await Context.Interaction.SendResponseAsync(
-                InteractionCallback.Message($":warning: {ex.Message}"));
+            _logger.LogWarning(ex, "Invalid reschedule request by user {UserId}", Context.User.Id);
+            await Context.Interaction.ModifyResponseAsync(message =>
+            {
+                message.Content = $":warning: {ex.Message}";
+            });
         }
         catch (Exception ex)
         {
             _logger.LogError(ex, "Failed to initiate reschedule for session {SessionId}", sessionId);
-            await Context.Interaction.SendResponseAsync(
-                InteractionCallback.Message(":boom: Ошибка при запуске голосования."));
+            await Context.Interaction.ModifyResponseAsync(message =>
+            {
+                message.Content = ":boom: Ошибка при запуске голосования.";
+            });
         }
     }
-
-    private static ulong GetResolvedPermissions(NetCord.Gateway.Guild guild, ulong userId)
-    {
-        if (!guild.Users.TryGetValue(userId, out var guildUser))
-            return 0;
-        ulong resolved = 0;
-        foreach (var roleId in guildUser.RoleIds)
-        {
-            if (guild.Roles.TryGetValue(roleId, out var role))
-                resolved |= (ulong)role.Permissions;
-        }
-        return resolved;
-    }
 }

src/GmRelay.DiscordBot/Features/Sessions/DiscordRescheduleVotingDeadlineService.cs

@@ -152,7 +152,7 @@ public sealed class DiscordRescheduleVotingDeadlineService(
                 """
                 SELECT sp.session_id AS SessionId,
                        p.display_name AS DisplayName,
-                       COALESCE(p.external_username, p.telegram_username) AS TelegramUsername,
+                       p.external_username AS TelegramUsername,
                        sp.registration_status AS RegistrationStatus
                 FROM session_participants sp
                 JOIN players p ON p.id = sp.player_id

src/GmRelay.DiscordBot/Features/Sessions/DiscordSessionInteractionModule.cs

@@ -1,8 +1,10 @@
 using GmRelay.DiscordBot.Infrastructure.Discord;
+using GmRelay.DiscordBot.Rendering;
 using GmRelay.Shared.Domain;
 using GmRelay.Shared.Features.Confirmation.HandleRsvp;
 using GmRelay.Shared.Features.Sessions.CreateSession;
 using GmRelay.Shared.Platform;
+using System.Collections;
 using System.Globalization;
 using NetCord;
 using NetCord.Rest;
@@ -14,6 +16,7 @@ public sealed class DiscordSessionInteractionModule(
     JoinSessionHandler joinSessionHandler,
     LeaveSessionHandler leaveSessionHandler,
     HandleRsvpHandler rsvpHandler,
+    DiscordDeleteSessionHandler deleteSessionHandler,
     DiscordRescheduleVoteHandler voteHandler,
     DiscordInteractionReplyCache interactionReplies,
     ILogger<DiscordSessionInteractionModule> logger) : ComponentInteractionModule<ButtonInteractionContext>
@@ -28,21 +31,22 @@ public sealed class DiscordSessionInteractionModule(
         }
 
         var input = CreateInput(parsedSessionId);
-        await RespondAsync(InteractionCallback.DeferredMessage(MessageFlags.Ephemeral));
+        await RespondAsync(InteractionCallback.DeferredModifyMessage);
+        SessionInteractionResult result;
         try
         {
-            await joinSessionHandler.HandleAsync(
-                DiscordSessionInteractionMapper.CreateJoinCommand(input),
+            result = await joinSessionHandler.HandleAsync(
+                DiscordSessionInteractionMapper.CreateJoinCommand(input) with { DeferScheduleUpdate = true },
                 CancellationToken.None);
         }
         catch (Exception ex)
         {
             logger.LogError(ex, "Failed to handle Discord join interaction for session {SessionId}", parsedSessionId);
-            await CompleteResponseAsync("Не удалось обработать кнопку.");
+            await FollowupEphemeralAsync("Не удалось обработать кнопку.");
             return;
         }
 
-        await CompleteWithStoredReplyAsync(input.InteractionId);
+        await CompleteScheduleUpdateResponseAsync(input.InteractionId, result);
     }
 
     [ComponentInteraction("leave_session")]
@@ -55,21 +59,56 @@ public sealed class DiscordSessionInteractionModule(
         }
 
         var input = CreateInput(parsedSessionId);
-        await RespondAsync(InteractionCallback.DeferredMessage(MessageFlags.Ephemeral));
+        await RespondAsync(InteractionCallback.DeferredModifyMessage);
+        SessionInteractionResult result;
         try
         {
-            await leaveSessionHandler.HandleAsync(
-                DiscordSessionInteractionMapper.CreateLeaveCommand(input),
+            result = await leaveSessionHandler.HandleAsync(
+                DiscordSessionInteractionMapper.CreateLeaveCommand(input) with { DeferScheduleUpdate = true },
                 CancellationToken.None);
         }
         catch (Exception ex)
         {
             logger.LogError(ex, "Failed to handle Discord leave interaction for session {SessionId}", parsedSessionId);
-            await CompleteResponseAsync("Не удалось обработать кнопку.");
+            await FollowupEphemeralAsync("Не удалось обработать кнопку.");
             return;
         }
 
-        await CompleteWithStoredReplyAsync(input.InteractionId);
+        await CompleteScheduleUpdateResponseAsync(input.InteractionId, result);
+    }
+
+    [ComponentInteraction("delete_session")]
+    public async Task DeleteAsync(string sessionId)
+    {
+        if (!Guid.TryParse(sessionId, out var parsedSessionId))
+        {
+            await RespondAsync(CreateEphemeralReply("Session button is outdated."));
+            return;
+        }
+
+        var input = CreateInput(parsedSessionId);
+        var member = Context.User as GuildInteractionUser;
+        var resolvedPermissions = member is null ? 0UL : (ulong)member.Permissions;
+
+        await RespondAsync(InteractionCallback.DeferredModifyMessage);
+        try
+        {
+            var result = await deleteSessionHandler.HandleAsync(
+                guildId: input.GuildId,
+                channelId: input.ChannelId,
+                userId: input.UserId,
+                resolvedPermissions: resolvedPermissions,
+                guildOwnerId: 0,
+                sessionId: parsedSessionId,
+                CancellationToken.None);
+
+            await CompleteDeleteResponseAsync(result);
+        }
+        catch (Exception ex)
+        {
+            logger.LogError(ex, "Failed to handle Discord delete interaction for session {SessionId}", parsedSessionId);
+            await FollowupEphemeralAsync("Не удалось удалить сессию.");
+        }
     }
 
     [ComponentInteraction("rsvp")]
@@ -124,7 +163,7 @@ public sealed class DiscordSessionInteractionModule(
         catch (Exception ex)
         {
             logger.LogError(ex, "Failed to handle Discord RSVP interaction for session {SessionId}", parsedSessionId);
-            await CompleteResponseAsync("Не удалось обработать кнопку.");
+            await CompleteResponseAsync("Не удалось обработать кнопку.");
             return;
         }
 
@@ -168,7 +207,7 @@ public sealed class DiscordSessionInteractionModule(
 
     private DiscordSessionInteractionInput CreateInput(Guid sessionId)
     {
-        var guild = Context.Guild
+        var guildId = Context.Interaction.GuildId?.ToString(CultureInfo.InvariantCulture)
             ?? throw new InvalidOperationException("Session buttons can only be used in a guild.");
         var message = Context.Interaction.Message
             ?? throw new InvalidOperationException("Session button interaction must include a message.");
@@ -176,7 +215,7 @@ public sealed class DiscordSessionInteractionModule(
         return new DiscordSessionInteractionInput(
             SessionId: sessionId,
             InteractionId: Context.Interaction.Id.ToString(System.Globalization.CultureInfo.InvariantCulture),
-            GuildId: guild.Id.ToString(CultureInfo.InvariantCulture),
+            GuildId: guildId,
             ChannelId: Context.Channel.Id.ToString(CultureInfo.InvariantCulture),
             MessageId: message.Id.ToString(CultureInfo.InvariantCulture),
             UserId: Context.User.Id,
@@ -190,9 +229,85 @@ public sealed class DiscordSessionInteractionModule(
         await CompleteResponseAsync(reply?.Text ?? "Session updated.");
     }
 
+    private async Task CompleteScheduleUpdateResponseAsync(string interactionId, SessionInteractionResult result)
+    {
+        var updatedView = result.UpdatedView;
+        if (updatedView is not null && SourceMessageHasDeleteAction())
+        {
+            updatedView = DiscordListSessionsHandler.AddManagerActions(updatedView);
+        }
+
+        if (updatedView is not null)
+        {
+            var (embeds, actionRows) = DiscordSessionBatchRenderer.Render(updatedView);
+            await ModifyResponseAsync(options =>
+            {
+                options.Embeds = embeds;
+                options.Components = actionRows;
+            });
+        }
+
+        var reply = interactionReplies.Take(interactionId);
+        await FollowupEphemeralAsync(reply?.Text ?? result.ReplyText);
+    }
+
+    private async Task CompleteDeleteResponseAsync(DiscordDeleteSessionResult result)
+    {
+        if (result.UpdatedView is not null)
+        {
+            var (embeds, actionRows) = DiscordSessionBatchRenderer.Render(result.UpdatedView);
+            await ModifyResponseAsync(options =>
+            {
+                options.Embeds = embeds;
+                options.Components = actionRows;
+            });
+        }
+        else if (result.EmptyMessage is not null)
+        {
+            await ModifyResponseAsync(options =>
+            {
+                options.Content = result.EmptyMessage;
+                options.Embeds = [];
+                options.Components = [];
+            });
+        }
+
+        await FollowupEphemeralAsync(result.ReplyText);
+    }
+
     private Task CompleteResponseAsync(string text) =>
         ModifyResponseAsync(options => options.Content = text);
 
+    private Task FollowupEphemeralAsync(string text) =>
+        FollowupAsync(new InteractionMessageProperties()
+            .WithContent(text)
+            .WithFlags(MessageFlags.Ephemeral));
+
+    private bool SourceMessageHasDeleteAction() =>
+        Context.Interaction.Message?.Components.Any(ComponentContainsDeleteAction) == true;
+
+    private static bool ComponentContainsDeleteAction(object? component)
+    {
+        if (component is null)
+            return false;
+
+        if (component is IInteractiveComponent interactive
+            && interactive.CustomId.StartsWith("delete_session:", StringComparison.Ordinal))
+            return true;
+
+        var nestedComponents = component.GetType().GetProperty("Components")?.GetValue(component) as IEnumerable;
+        if (nestedComponents is null)
+            return false;
+
+        foreach (var nestedComponent in nestedComponents)
+        {
+            if (ComponentContainsDeleteAction(nestedComponent))
+                return true;
+        }
+
+        return false;
+    }
+
     private static InteractionCallbackProperties CreateEphemeralReply(string text) =>
         InteractionCallback.Message(
             new InteractionMessageProperties()

src/GmRelay.DiscordBot/GmRelay.DiscordBot.csproj

@@ -6,11 +6,14 @@
     <Nullable>enable</Nullable>
     <ImplicitUsings>enable</ImplicitUsings>
     <UserSecretsId>dotnet-GmRelay.DiscordBot-issue-26</UserSecretsId>
+    <!-- DiscordBot uses vanilla Dapper in its own handlers; DAP005 requires AOT-enabled Dapper -->
+    <NoWarn>$(NoWarn);DAP005</NoWarn>
   </PropertyGroup>
 
   <ItemGroup>
     <PackageReference Include="Aspire.Npgsql" Version="13.2.2" />
     <PackageReference Include="Dapper" Version="2.1.72" />
+    <PackageReference Include="Dapper.AOT" Version="1.0.48" />
     <PackageReference Include="Microsoft.Extensions.Hosting" Version="10.0.5" />
     <PackageReference Include="NetCord.Hosting" Version="1.0.0-alpha.489" />
     <PackageReference Include="NetCord.Hosting.Services" Version="1.0.0-alpha.489" />

src/GmRelay.DiscordBot/Infrastructure/Discord/DiscordPlatformMessenger.cs

@@ -98,17 +98,34 @@ public sealed class DiscordPlatformMessenger : IPlatformMessenger
         CancellationToken ct)
     {
         var channelId = GetChannelId(request.Group);
-        var message = await restClient.SendMessageAsync(
-            channelId,
-            new MessageProperties()
-                .WithEmbeds([BuildConfirmationEmbed(request)])
-                .WithComponents(BuildRsvpRows(request.SessionId, disabled: false)));
+        try
+        {
+            var message = await restClient.SendMessageAsync(
+                channelId,
+                new MessageProperties()
+                    .WithEmbeds([BuildConfirmationEmbed(request)])
+                    .WithComponents(BuildRsvpRows(request.SessionId, disabled: false)));
 
-        return new PlatformMessageRef(
-            PlatformKind.Discord,
-            request.Group.ExternalGroupId,
-            null,
-            message.Id.ToString(CultureInfo.InvariantCulture));
+            logger?.LogInformation(
+                "Confirmation request sent to Discord channel {ChannelId}, message id {MessageId}",
+                channelId,
+                message.Id);
+
+            return new PlatformMessageRef(
+                PlatformKind.Discord,
+                request.Group.ExternalGroupId,
+                null,
+                message.Id.ToString(CultureInfo.InvariantCulture));
+        }
+        catch (Exception ex)
+        {
+            logger?.LogError(
+                ex,
+                "Failed to send confirmation request to Discord channel {ChannelId} for session {SessionId}",
+                channelId,
+                request.SessionId);
+            throw;
+        }
     }
 
     public async Task UpdateConfirmationRequestAsync(PlatformRsvpMessageUpdate update, CancellationToken ct)
@@ -135,15 +152,32 @@ public sealed class DiscordPlatformMessenger : IPlatformMessenger
         CancellationToken ct)
     {
         var channelId = GetChannelId(notification.Group);
-        var message = await restClient.SendMessageAsync(
-            channelId,
-            new MessageProperties().WithEmbeds([BuildJoinLinkEmbed(notification)]));
+        try
+        {
+            var message = await restClient.SendMessageAsync(
+                channelId,
+                new MessageProperties().WithEmbeds([BuildJoinLinkEmbed(notification)]));
 
-        return new PlatformMessageRef(
-            PlatformKind.Discord,
-            notification.Group.ExternalGroupId,
-            null,
-            message.Id.ToString(CultureInfo.InvariantCulture));
+            logger?.LogInformation(
+                "Join link sent to Discord channel {ChannelId}, message id {MessageId}",
+                channelId,
+                message.Id);
+
+            return new PlatformMessageRef(
+                PlatformKind.Discord,
+                notification.Group.ExternalGroupId,
+                null,
+                message.Id.ToString(CultureInfo.InvariantCulture));
+        }
+        catch (Exception ex)
+        {
+            logger?.LogError(
+                ex,
+                "Failed to send join link to Discord channel {ChannelId} for session {SessionId}",
+                channelId,
+                notification.SessionId);
+            throw;
+        }
     }
 
     public async Task SendDirectSessionNotificationAsync(
@@ -272,14 +306,16 @@ public sealed class DiscordPlatformMessenger : IPlatformMessenger
             ? "—"
             : string.Join(", ", notification.ConfirmedPlayers.Select(p => Mention(p.User)));
 
-        return new EmbedProperties()
+        var embed = new EmbedProperties()
             .WithTitle($"Ссылка на игру: {notification.Title}")
             .WithDescription(
                 $"Время: **{notification.ScheduledAt.FormatMoscow()}** (МСК)\n" +
                 $"Ссылка: {notification.JoinLink}\n\n" +
                 $"Участники: {mentions}")
-            .WithUrl(notification.JoinLink)
             .WithColor(new Color(0x57F287));
+
+        var embedUrl = DiscordEmbedUrls.NormalizeHttpUrl(notification.JoinLink);
+        return embedUrl is null ? embed : embed.WithUrl(embedUrl);
     }
 
     private static IReadOnlyList<ActionRowProperties> BuildRsvpRows(Guid sessionId, bool disabled)

src/GmRelay.DiscordBot/Program.cs

@@ -18,8 +18,10 @@ using Microsoft.Extensions.DependencyInjection;
 using NetCord;
 using NetCord.Gateway;
 using NetCord.Hosting.Gateway;
+using NetCord.Hosting.Services;
 using NetCord.Hosting.Services.ApplicationCommands;
 using NetCord.Hosting.Services.ComponentInteractions;
+using NetCord.Services.ApplicationCommands;
 using NetCord.Services.ComponentInteractions;
 using Npgsql;
 
@@ -34,6 +36,8 @@ discordOptions.Validate();
 
 builder.Services.AddSingleton(discordOptions);
 
+builder.Logging.AddConsole();
+
 builder.Services.AddSingleton<NpgsqlDataSource>(sp =>
 {
     var config = sp.GetRequiredService<IConfiguration>();
@@ -52,6 +56,7 @@ builder.Services.AddSingleton<NpgsqlDataSource>(sp =>
 
 builder.Services.AddSingleton<DiscordPermissionChecker>();
 builder.Services.AddSingleton<DiscordListSessionsHandler>();
+builder.Services.AddSingleton<DiscordDeleteSessionHandler>();
 builder.Services.AddSingleton<DiscordNewSessionHandler>();
 builder.Services.AddSingleton<DiscordRescheduleHandler>();
 builder.Services.AddSingleton<DiscordRescheduleVoteHandler>();
@@ -82,12 +87,13 @@ builder.Services
         options.Token = discordOptions.Token;
         options.Intents = GatewayIntents.Guilds;
     })
-    .AddApplicationCommands()
+    .AddApplicationCommands<SlashCommandInteraction, SlashCommandContext>()
     .AddComponentInteractions<ButtonInteraction, ButtonInteractionContext>()
     .AddGatewayHandlers(typeof(Program).Assembly);
 
 var host = builder.Build();
 
 host.AddSlashCommand("ping", "Checks whether GM-Relay Discord is online.", () => "Pong!");
+host.AddModules(typeof(Program).Assembly);
 
 await host.RunAsync();

src/GmRelay.DiscordBot/Rendering/DiscordEmbedUrls.cs

@@ -0,0 +1,43 @@
+namespace GmRelay.DiscordBot.Rendering;
+
+public static class DiscordEmbedUrls
+{
+    public static string? NormalizeHttpUrl(string? value)
+    {
+        if (string.IsNullOrWhiteSpace(value))
+            return null;
+
+        var candidate = value.Trim();
+        if (IsSupportedHttpUrl(candidate, out var normalized))
+            return normalized;
+
+        if (candidate.Contains("://", StringComparison.Ordinal))
+            return null;
+
+        return IsSupportedHttpUrl($"https://{candidate}", out normalized)
+            && HasPublicHost(normalized)
+                ? normalized
+                : null;
+    }
+
+    private static bool IsSupportedHttpUrl(string value, out string normalized)
+    {
+        normalized = string.Empty;
+
+        if (!Uri.TryCreate(value, UriKind.Absolute, out var uri))
+            return false;
+
+        if (!string.Equals(uri.Scheme, Uri.UriSchemeHttp, StringComparison.OrdinalIgnoreCase)
+            && !string.Equals(uri.Scheme, Uri.UriSchemeHttps, StringComparison.OrdinalIgnoreCase))
+        {
+            return false;
+        }
+
+        normalized = uri.ToString();
+        return true;
+    }
+
+    private static bool HasPublicHost(string value) =>
+        Uri.TryCreate(value, UriKind.Absolute, out var uri)
+        && uri.Host.Contains('.', StringComparison.Ordinal);
+}

src/GmRelay.DiscordBot/Rendering/DiscordSessionBatchRenderer.cs

@@ -70,9 +70,10 @@ public static class DiscordSessionBatchRenderer
                 .WithInline()
         };
 
-        if (!string.IsNullOrEmpty(session.JoinLink))
+        var embedUrl = DiscordEmbedUrls.NormalizeHttpUrl(session.JoinLink);
+        if (embedUrl is not null)
         {
-            embed = embed.WithUrl(session.JoinLink);
+            embed = embed.WithUrl(embedUrl);
         }
 
         embed = embed.WithColor(GetColor(session));

src/GmRelay.DiscordBot/packages.lock.json

@@ -28,6 +28,12 @@
         "resolved": "2.1.72",
         "contentHash": "ns4mGqQd9a/MhP8m6w556vVlZIa0/MfUu03zrxjZC/jlr1uVCsUac8bkdB+Fs98Llbd56rRSo1eZH5VVmeGZyw=="
       },
+      "Dapper.AOT": {
+        "type": "Direct",
+        "requested": "[1.0.48, )",
+        "resolved": "1.0.48",
+        "contentHash": "rsLM3yKr4g+YKKox9lhc8D+kz67P7Q9+xdyn1LmCsoYr1kYpJSm+Nt6slo5UrfUrcTiGJ57zUlyO8XUdV7G7iA=="
+      },
       "Microsoft.Extensions.Hosting": {
         "type": "Direct",
         "requested": "[10.0.5, )",

src/GmRelay.Shared/Features/Confirmation/HandleRsvp/HandleRsvpHandler.cs

@@ -56,8 +56,8 @@ public sealed class HandleRsvpHandler(
                 FROM session_participants sp
                 JOIN players p ON p.id = sp.player_id
                 WHERE sp.session_id = @SessionId
-                  AND COALESCE(p.platform, 'Telegram') = @Platform
-                  AND COALESCE(p.external_user_id, p.telegram_id::TEXT) = @ExternalUserId
+                  AND p.platform = @Platform
+                  AND p.external_user_id = @ExternalUserId
                   AND sp.is_gm = false
                   AND sp.registration_status = @Active
             )
@@ -90,8 +90,8 @@ public sealed class HandleRsvpHandler(
               AND  player_id = (
                     SELECT id
                     FROM players
-                    WHERE COALESCE(platform, 'Telegram') = @Platform
-                      AND COALESCE(external_user_id, telegram_id::TEXT) = @ExternalUserId
+                    WHERE platform = @Platform
+                      AND external_user_id = @ExternalUserId
                     LIMIT 1
               )
               AND  registration_status = @Active
@@ -265,10 +265,10 @@ public sealed class HandleRsvpHandler(
 
             var participants = (await connection.QueryAsync<ParticipantRsvpRow>(
                 """
-                SELECT COALESCE(p.platform, 'Telegram') AS Platform,
-                       COALESCE(p.external_user_id, p.telegram_id::TEXT) AS ExternalUserId,
+                SELECT p.platform AS Platform,
+                       p.external_user_id AS ExternalUserId,
                        p.display_name AS DisplayName,
-                       COALESCE(p.external_username, p.telegram_username) AS ExternalUsername,
+                       p.external_username AS ExternalUsername,
                        sp.rsvp_status AS RsvpStatus,
                        sp.registration_status AS RegistrationStatus,
                        sp.is_gm AS IsGm
@@ -312,23 +312,13 @@ public sealed class HandleRsvpHandler(
         var rows = await connection.QueryAsync<RsvpRecipientRow>(
             """
             SELECT DISTINCT
-                   COALESCE(p.platform, 'Telegram') AS Platform,
-                   COALESCE(p.external_user_id, p.telegram_id::TEXT) AS ExternalUserId,
+                   p.platform AS Platform,
+                   p.external_user_id AS ExternalUserId,
                    p.display_name AS DisplayName,
-                   COALESCE(p.external_username, p.telegram_username) AS ExternalUsername
+                   p.external_username AS ExternalUsername
             FROM group_managers gm
             JOIN players p ON p.id = gm.player_id
             WHERE gm.group_id = @GroupId
-            UNION
-            SELECT DISTINCT
-                   COALESCE(p.platform, 'Telegram') AS Platform,
-                   COALESCE(p.external_user_id, p.telegram_id::TEXT) AS ExternalUserId,
-                   p.display_name AS DisplayName,
-                   COALESCE(p.external_username, p.telegram_username) AS ExternalUsername
-            FROM game_groups g
-            JOIN players p ON p.telegram_id = g.gm_telegram_id
-            WHERE g.id = @GroupId
-              AND g.gm_telegram_id IS NOT NULL
             """,
             new { GroupId = groupId },
             transaction);

src/GmRelay.Shared/Features/Confirmation/SendConfirmation/SendConfirmationHandler.cs

@@ -45,10 +45,10 @@ public sealed class SendConfirmationHandler(
                    s.title,
                    s.scheduled_at AS ScheduledAt,
                    s.group_id AS GroupId,
-                   COALESCE(g.platform, 'Telegram') AS Platform,
-                   COALESCE(g.external_group_id, g.telegram_chat_id::TEXT) AS ExternalGroupId,
+                   g.platform AS Platform,
+                   g.external_group_id AS ExternalGroupId,
                    g.name AS DisplayName,
-                   COALESCE(g.external_channel_id, g.telegram_chat_id::TEXT) AS ExternalChannelId,
+                   g.external_channel_id AS ExternalChannelId,
                    s.thread_id AS ThreadId,
                    s.notification_mode AS NotificationMode
             FROM sessions s
@@ -65,10 +65,10 @@ public sealed class SendConfirmationHandler(
 
         var participants = (await connection.QueryAsync<ConfirmationParticipantRow>(
             """
-            SELECT COALESCE(p.platform, 'Telegram') AS Platform,
-                   COALESCE(p.external_user_id, p.telegram_id::TEXT) AS ExternalUserId,
+            SELECT p.platform AS Platform,
+                   p.external_user_id AS ExternalUserId,
                    p.display_name AS DisplayName,
-                   COALESCE(p.external_username, p.telegram_username) AS ExternalUsername,
+                   p.external_username AS ExternalUsername,
                    sp.rsvp_status AS RsvpStatus,
                    sp.registration_status AS RegistrationStatus,
                    sp.is_gm AS IsGm

src/GmRelay.Shared/Features/Reminders/SendJoinLink/SendJoinLinkHandler.cs

@@ -47,10 +47,10 @@ public sealed class SendJoinLinkHandler(
                    s.title,
                    s.join_link AS JoinLink,
                    s.scheduled_at AS ScheduledAt,
-                   COALESCE(g.platform, 'Telegram') AS Platform,
-                   COALESCE(g.external_group_id, g.telegram_chat_id::TEXT) AS ExternalGroupId,
+                   g.platform AS Platform,
+                   g.external_group_id AS ExternalGroupId,
                    g.name AS DisplayName,
-                   COALESCE(g.external_channel_id, g.telegram_chat_id::TEXT) AS ExternalChannelId,
+                   g.external_channel_id AS ExternalChannelId,
                    s.thread_id AS ThreadId,
                    s.notification_mode AS NotificationMode
             FROM sessions s
@@ -58,14 +58,14 @@ public sealed class SendJoinLinkHandler(
             WHERE s.id = @SessionId
               AND s.status = @Confirmed
               AND (
-                    (COALESCE(g.platform, 'Telegram') = 'Telegram' AND s.link_message_id IS NULL)
+                    (g.platform = 'Telegram' AND s.link_message_id IS NULL)
                     OR (
-                        COALESCE(g.platform, 'Telegram') <> 'Telegram'
+                        g.platform <> 'Telegram'
                         AND NOT EXISTS (
                             SELECT 1
                             FROM platform_messages pm
                             WHERE pm.session_id = s.id
-                              AND pm.platform = COALESCE(g.platform, 'Telegram')
+                              AND pm.platform = g.platform
                               AND pm.purpose = 'join_link'
                         )
                     )
@@ -81,10 +81,10 @@ public sealed class SendJoinLinkHandler(
 
         var players = (await connection.QueryAsync<JoinLinkPlayerRow>(
             """
-            SELECT COALESCE(p.platform, 'Telegram') AS Platform,
-                   COALESCE(p.external_user_id, p.telegram_id::TEXT) AS ExternalUserId,
+            SELECT p.platform AS Platform,
+                   p.external_user_id AS ExternalUserId,
                    p.display_name AS DisplayName,
-                   COALESCE(p.external_username, p.telegram_username) AS ExternalUsername,
+                   p.external_username AS ExternalUsername,
                    sp.rsvp_status AS RsvpStatus,
                    sp.registration_status AS RegistrationStatus,
                    sp.is_gm AS IsGm

src/GmRelay.Shared/Features/Reminders/SendOneHourReminder/SendOneHourReminderHandler.cs

@@ -56,10 +56,10 @@ public sealed class SendOneHourReminderHandler(
 
         var recipients = (await connection.QueryAsync<OneHourReminderRecipientRow>(
             """
-            SELECT COALESCE(p.platform, 'Telegram') AS Platform,
-                   COALESCE(p.external_user_id, p.telegram_id::TEXT) AS ExternalUserId,
+            SELECT p.platform AS Platform,
+                   p.external_user_id AS ExternalUserId,
                    p.display_name AS DisplayName,
-                   COALESCE(p.external_username, p.telegram_username) AS ExternalUsername
+                   p.external_username AS ExternalUsername
             FROM session_participants sp
             JOIN players p ON p.id = sp.player_id
             WHERE sp.session_id = @SessionId

src/GmRelay.Shared/Features/Sessions/CreateSession/JoinSessionHandler.cs

@@ -13,7 +13,12 @@ public sealed record JoinSessionCommand(
     PlatformUser User,
     string InteractionId,
     PlatformGroup Group,
-    PlatformMessageRef ScheduleMessage);
+    PlatformMessageRef ScheduleMessage,
+    bool DeferScheduleUpdate = false);
+
+public sealed record SessionInteractionResult(
+    string ReplyText,
+    SessionBatchViewModel? UpdatedView = null);
 
 // DTOs for AOT compilation
 internal sealed record JoinSessionBatchDto(Guid BatchId, string Title, string Status, int? MaxPlayers);
@@ -24,7 +29,7 @@ public sealed class JoinSessionHandler(
     IScheduleMessageUpdateLock scheduleUpdateLock,
     ILogger<JoinSessionHandler> logger)
 {
-    public async Task HandleAsync(JoinSessionCommand command, CancellationToken ct)
+    public async Task<SessionInteractionResult> HandleAsync(JoinSessionCommand command, CancellationToken ct)
     {
         await using var updateLock = await scheduleUpdateLock.AcquireAsync(command.ScheduleMessage, ct);
         await using var connection = await dataSource.OpenConnectionAsync(ct);
@@ -35,30 +40,19 @@ public sealed class JoinSessionHandler(
         {
             // 1. Убеждаемся, что игрок есть в базе
             var platform = command.User.Platform.ToString();
-            var legacyTelegramId = command.User.Platform == PlatformKind.Telegram
-                ? long.Parse(command.User.ExternalUserId, CultureInfo.InvariantCulture)
-                : (long?)null;
-            var legacyTelegramUsername = command.User.Platform == PlatformKind.Telegram
-                ? command.User.ExternalUsername
-                : null;
 
             var playerId = await connection.ExecuteScalarAsync<Guid>(
-                @"INSERT INTO players (telegram_id, display_name, telegram_username, platform, external_user_id, external_username)
-                  VALUES (@LegacyTelegramId, @Name, @LegacyTelegramUsername, @Platform, @ExternalUserId, @ExternalUsername)
+                @"INSERT INTO players (display_name, platform, external_user_id, external_username)
+                  VALUES (@Name, @Platform, @ExternalUserId, @ExternalUsername)
                   ON CONFLICT (platform, external_user_id)
                   WHERE platform IS NOT NULL AND external_user_id IS NOT NULL
                   DO UPDATE
                   SET display_name = EXCLUDED.display_name,
-                      telegram_username = COALESCE(EXCLUDED.telegram_username, players.telegram_username),
-                      platform = EXCLUDED.platform,
-                      external_user_id = EXCLUDED.external_user_id,
                       external_username = EXCLUDED.external_username
                   RETURNING id;",
                 new
                 {
-                    LegacyTelegramId = legacyTelegramId,
                     Name = command.User.DisplayName,
-                    LegacyTelegramUsername = legacyTelegramUsername,
                     Platform = platform,
                     command.User.ExternalUserId,
                     command.User.ExternalUsername
@@ -77,15 +71,13 @@ public sealed class JoinSessionHandler(
             if (batchInfo is null)
             {
                 await transaction.RollbackAsync(ct);
-                await AnswerAsync(command.InteractionId, "Сессия не найдена.", ct);
-                return;
+                return await AnswerAsync(command.InteractionId, "Сессия не найдена.", ct);
             }
 
             if (SessionStatus.IsCancelled(batchInfo.Status))
             {
                 await transaction.RollbackAsync(ct);
-                await AnswerAsync(command.InteractionId, "Сессия уже отменена.", ct);
-                return;
+                return await AnswerAsync(command.InteractionId, "Сессия уже отменена.", ct);
             }
 
             var existingRegistrationStatus = await connection.ExecuteScalarAsync<string?>(
@@ -105,8 +97,7 @@ public sealed class JoinSessionHandler(
                 var alreadyText = existingRegistrationStatus == ParticipantRegistrationStatus.Waitlisted
                     ? "Вы уже в листе ожидания!"
                     : "Вы уже записаны!";
-                await AnswerAsync(command.InteractionId, alreadyText, ct);
-                return;
+                return await AnswerAsync(command.InteractionId, alreadyText, ct);
             }
 
             var activeParticipants = await connection.ExecuteScalarAsync<int>(
@@ -139,8 +130,7 @@ public sealed class JoinSessionHandler(
             if (inserted == 0)
             {
                 await transaction.RollbackAsync(ct);
-                await AnswerAsync(command.InteractionId, "Вы уже записаны!", ct);
-                return;
+                return await AnswerAsync(command.InteractionId, "Вы уже записаны!", ct);
             }
 
             // Загружаем весь батч для перерисовки
@@ -154,7 +144,7 @@ public sealed class JoinSessionHandler(
             var batchParticipants = await connection.QueryAsync<ParticipantBatchDto>(
                 @"SELECT sp.session_id as SessionId,
                          p.display_name as DisplayName,
-                         COALESCE(p.external_username, p.telegram_username) as TelegramUsername,
+                         p.external_username as TelegramUsername,
                          sp.registration_status as RegistrationStatus
                   FROM session_participants sp
                   JOIN players p ON sp.player_id = p.id
@@ -168,17 +158,20 @@ public sealed class JoinSessionHandler(
 
             // 4. Перерисовываем сообщение
             var view = SessionBatchViewBuilder.Build(batchInfo.Title, batchSessions.ToList(), batchParticipants.ToList());
-            await messenger.UpdateScheduleAsync(
-                new PlatformScheduleMessage(
-                    command.Group,
-                    view,
-                    command.ScheduleMessage),
-                ct);
+            if (!command.DeferScheduleUpdate)
+            {
+                await messenger.UpdateScheduleAsync(
+                    new PlatformScheduleMessage(
+                        command.Group,
+                        view,
+                        command.ScheduleMessage),
+                    ct);
+            }
 
             var callbackText = registrationStatus == ParticipantRegistrationStatus.Waitlisted
                 ? "Основной состав заполнен. Вы добавлены в лист ожидания."
                 : "Вы успешно записаны!";
-            await AnswerAsync(command.InteractionId, callbackText, ct);
+            return await AnswerAsync(command.InteractionId, callbackText, ct, view);
         }
         catch (Exception ex)
         {
@@ -191,10 +184,17 @@ public sealed class JoinSessionHandler(
             var errorText = transactionCommitted
                 ? "Регистрация сохранена, но не удалось обновить сообщение расписания."
                 : "Произошла ошибка при регистрации.";
-            await AnswerAsync(command.InteractionId, errorText, ct);
+            return await AnswerAsync(command.InteractionId, errorText, ct);
         }
     }
 
-    private Task AnswerAsync(string interactionId, string text, CancellationToken ct) =>
-        messenger.AnswerInteractionAsync(new PlatformInteractionReply(interactionId, text), ct);
+    private async Task<SessionInteractionResult> AnswerAsync(
+        string interactionId,
+        string text,
+        CancellationToken ct,
+        SessionBatchViewModel? updatedView = null)
+    {
+        await messenger.AnswerInteractionAsync(new PlatformInteractionReply(interactionId, text), ct);
+        return new SessionInteractionResult(text, updatedView);
+    }
 }

src/GmRelay.Shared/Features/Sessions/CreateSession/LeaveSessionHandler.cs

@@ -12,7 +12,8 @@ public sealed record LeaveSessionCommand(
     PlatformUser User,
     string InteractionId,
     PlatformGroup Group,
-    PlatformMessageRef ScheduleMessage);
+    PlatformMessageRef ScheduleMessage,
+    bool DeferScheduleUpdate = false);
 
 internal sealed record LeaveSessionInfoDto(string Title, Guid BatchId, string Status, int? MaxPlayers);
 internal sealed record LeaveSessionParticipantDto(Guid ParticipantRowId, string DisplayName, string RegistrationStatus);
@@ -24,7 +25,7 @@ public sealed class LeaveSessionHandler(
     IScheduleMessageUpdateLock scheduleUpdateLock,
     ILogger<LeaveSessionHandler> logger)
 {
-    public async Task HandleAsync(LeaveSessionCommand command, CancellationToken ct)
+    public async Task<SessionInteractionResult> HandleAsync(LeaveSessionCommand command, CancellationToken ct)
     {
         await using var updateLock = await scheduleUpdateLock.AcquireAsync(command.ScheduleMessage, ct);
         await using var connection = await dataSource.OpenConnectionAsync(ct);
@@ -49,15 +50,13 @@ public sealed class LeaveSessionHandler(
             if (session is null)
             {
                 await transaction.RollbackAsync(ct);
-                await AnswerAsync(command.InteractionId, "Сессия не найдена.", ct);
-                return;
+                return await AnswerAsync(command.InteractionId, "Сессия не найдена.", ct);
             }
 
             if (SessionStatus.IsCancelled(session.Status))
             {
                 await transaction.RollbackAsync(ct);
-                await AnswerAsync(command.InteractionId, "Сессия уже отменена.", ct);
-                return;
+                return await AnswerAsync(command.InteractionId, "Сессия уже отменена.", ct);
             }
 
             var platform = command.User.Platform.ToString();
@@ -81,8 +80,7 @@ public sealed class LeaveSessionHandler(
             if (participant is null)
             {
                 await transaction.RollbackAsync(ct);
-                await AnswerAsync(command.InteractionId, "Вы не записаны на эту сессию.", ct);
-                return;
+                return await AnswerAsync(command.InteractionId, "Вы не записаны на эту сессию.", ct);
             }
 
             await connection.ExecuteAsync(
@@ -175,7 +173,7 @@ public sealed class LeaveSessionHandler(
                 """
                 SELECT sp.session_id AS SessionId,
                        p.display_name AS DisplayName,
-                       COALESCE(p.external_username, p.telegram_username) AS TelegramUsername,
+                       p.external_username AS TelegramUsername,
                        sp.registration_status AS RegistrationStatus
                 FROM session_participants sp
                 JOIN players p ON sp.player_id = p.id
@@ -190,12 +188,15 @@ public sealed class LeaveSessionHandler(
             transactionCommitted = true;
 
             var view = SessionBatchViewBuilder.Build(session.Title, batchSessions, batchParticipants);
-            await messenger.UpdateScheduleAsync(
-                new PlatformScheduleMessage(
-                    command.Group,
-                    view,
-                    command.ScheduleMessage),
-                ct);
+            if (!command.DeferScheduleUpdate)
+            {
+                await messenger.UpdateScheduleAsync(
+                    new PlatformScheduleMessage(
+                        command.Group,
+                        view,
+                        command.ScheduleMessage),
+                    ct);
+            }
 
             var callbackText = participant.RegistrationStatus == ParticipantRegistrationStatus.Waitlisted
                 ? "Вы удалены из листа ожидания."
@@ -203,7 +204,7 @@ public sealed class LeaveSessionHandler(
                     ? "Вы отписались от сессии."
                     : $"Вы отписались от сессии. Место получил(а) {promotedDisplayName}.";
 
-            await AnswerAsync(command.InteractionId, callbackText, ct);
+            return await AnswerAsync(command.InteractionId, callbackText, ct, view);
         }
         catch (Exception ex)
         {
@@ -216,10 +217,17 @@ public sealed class LeaveSessionHandler(
             var errorText = transactionCommitted
                 ? "Запись снята, но не удалось обновить сообщение расписания."
                 : "Произошла ошибка при отмене записи.";
-            await AnswerAsync(command.InteractionId, errorText, ct);
+            return await AnswerAsync(command.InteractionId, errorText, ct);
         }
     }
 
-    private Task AnswerAsync(string interactionId, string text, CancellationToken ct) =>
-        messenger.AnswerInteractionAsync(new PlatformInteractionReply(interactionId, text), ct);
+    private async Task<SessionInteractionResult> AnswerAsync(
+        string interactionId,
+        string text,
+        CancellationToken ct,
+        SessionBatchViewModel? updatedView = null)
+    {
+        await messenger.AnswerInteractionAsync(new PlatformInteractionReply(interactionId, text), ct);
+        return new SessionInteractionResult(text, updatedView);
+    }
 }

src/GmRelay.Shared/Features/Sessions/RescheduleSession/RescheduleVotingFinalizer.cs

@@ -78,8 +78,8 @@ public sealed class RescheduleVotingFinalizer(
             """
             SELECT p.id AS PlayerId,
                    p.display_name AS DisplayName,
-                   p.telegram_username AS TelegramUsername,
-                   p.telegram_id AS TelegramId
+                   p.external_username AS TelegramUsername,
+                   p.external_user_id::BIGINT AS TelegramId
             FROM session_participants sp
             JOIN players p ON p.id = sp.player_id
             WHERE sp.session_id = @SessionId
@@ -107,7 +107,7 @@ public sealed class RescheduleVotingFinalizer(
             SELECT rov.option_id AS OptionId,
                    p.id AS PlayerId,
                    p.display_name AS DisplayName,
-                   p.telegram_username AS TelegramUsername
+                   p.external_username AS TelegramUsername
             FROM reschedule_option_votes rov
             JOIN players p ON p.id = rov.player_id
             WHERE rov.proposal_id = @ProposalId

src/GmRelay.Shared/Infrastructure/Scheduling/SessionSchedulerService.cs

@@ -1,3 +1,4 @@
+using System.Collections.Concurrent;
 using GmRelay.Shared.Features.Confirmation.SendConfirmation;
 using GmRelay.Shared.Features.Reminders.SendJoinLink;
 using GmRelay.Shared.Features.Reminders.SendOneHourReminder;
@@ -20,6 +21,11 @@ public sealed class SessionSchedulerService(
     ILogger<SessionSchedulerService> logger) : BackgroundService
 {
     private static readonly TimeSpan TickInterval = TimeSpan.FromMinutes(1);
+    private static readonly TimeSpan BackoffDuration = TimeSpan.FromMinutes(15);
+
+    private readonly ConcurrentDictionary<Guid, DateTimeOffset> _confirmationBackoff = new();
+    private readonly ConcurrentDictionary<Guid, DateTimeOffset> _oneHourBackoff = new();
+    private readonly ConcurrentDictionary<Guid, DateTimeOffset> _joinLinkBackoff = new();
 
     protected override async Task ExecuteAsync(CancellationToken stoppingToken)
     {
@@ -71,14 +77,30 @@ public sealed class SessionSchedulerService(
 
         foreach (var sessionId in sessionIds)
         {
+            if (_confirmationBackoff.TryGetValue(sessionId, out var backoffUntil) && backoffUntil > now)
+            {
+                logger.LogDebug(
+                    "Skipping confirmation for session {SessionId} until {Backoff}",
+                    sessionId,
+                    backoffUntil);
+                continue;
+            }
+
             try
             {
                 await confirmationHandler.HandleAsync(sessionId, ct);
+                _confirmationBackoff.TryRemove(sessionId, out _);
                 logger.LogInformation("Confirmation sent for session {SessionId}", sessionId);
             }
             catch (Exception ex)
             {
-                logger.LogError(ex, "Failed to send confirmation for session {SessionId}", sessionId);
+                var nextAttempt = now.Add(BackoffDuration);
+                _confirmationBackoff[sessionId] = nextAttempt;
+                logger.LogError(
+                    ex,
+                    "Failed to send confirmation for session {SessionId}, backing off until {Backoff}",
+                    sessionId,
+                    nextAttempt);
             }
         }
     }
@@ -98,14 +120,30 @@ public sealed class SessionSchedulerService(
 
         foreach (var sessionId in sessionIds)
         {
+            if (_oneHourBackoff.TryGetValue(sessionId, out var backoffUntil) && backoffUntil > now)
+            {
+                logger.LogDebug(
+                    "Skipping one-hour reminder for session {SessionId} until {Backoff}",
+                    sessionId,
+                    backoffUntil);
+                continue;
+            }
+
             try
             {
                 await oneHourReminderHandler.HandleAsync(sessionId, ct);
+                _oneHourBackoff.TryRemove(sessionId, out _);
                 logger.LogInformation("One-hour reminder processed for session {SessionId}", sessionId);
             }
             catch (Exception ex)
             {
-                logger.LogError(ex, "Failed to process one-hour reminder for session {SessionId}", sessionId);
+                var nextAttempt = now.Add(BackoffDuration);
+                _oneHourBackoff[sessionId] = nextAttempt;
+                logger.LogError(
+                    ex,
+                    "Failed to process one-hour reminder for session {SessionId}, backing off until {Backoff}",
+                    sessionId,
+                    nextAttempt);
             }
         }
     }
@@ -125,14 +163,30 @@ public sealed class SessionSchedulerService(
 
         foreach (var sessionId in sessionIds)
         {
+            if (_joinLinkBackoff.TryGetValue(sessionId, out var backoffUntil) && backoffUntil > now)
+            {
+                logger.LogDebug(
+                    "Skipping join link for session {SessionId} until {Backoff}",
+                    sessionId,
+                    backoffUntil);
+                continue;
+            }
+
             try
             {
                 await joinLinkHandler.HandleAsync(sessionId, ct);
+                _joinLinkBackoff.TryRemove(sessionId, out _);
                 logger.LogInformation("Join link sent for session {SessionId}", sessionId);
             }
             catch (Exception ex)
             {
-                logger.LogError(ex, "Failed to send join link for session {SessionId}", sessionId);
+                var nextAttempt = now.Add(BackoffDuration);
+                _joinLinkBackoff[sessionId] = nextAttempt;
+                logger.LogError(
+                    ex,
+                    "Failed to send join link for session {SessionId}, backing off until {Backoff}",
+                    sessionId,
+                    nextAttempt);
             }
         }
     }

src/GmRelay.Web/Components/Layout/NavMenu.razor

@@ -34,6 +34,13 @@
                     </svg>
                     Шаблоны
                 </NavLink>
+                <NavLink class="nav-item" href="profile" @onclick="CloseMenu">
+                    <svg class="nav-icon" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+                        <path d="M20 21v-2a4 4 0 0 0-4-4H8a4 4 0 0 0-4 4v2"/>
+                        <circle cx="12" cy="7" r="4"/>
+                    </svg>
+                    Профиль
+                </NavLink>
             </div>
 
             <div class="nav-footer">
@@ -66,7 +73,7 @@
                     </button>
                 </form>
 
-                <div class="nav-version">v2.8.0</div>
+                <div class="nav-version">v3.1.0</div>
             </div>
         </Authorized>
         <NotAuthorized>

src/GmRelay.Web/Components/Pages/Home.razor

@@ -44,9 +44,14 @@
                     <div class="group-card-icon">🎮</div>
                     <h3 class="group-card-title">@group.Name</h3>
                     <p class="group-card-id">ID: @(group.Platform == "Discord" ? group.ExternalGroupId : group.TelegramChatId.ToString())</p>
-                    <span class="status-badge @(group.ManagerRole == GroupManagerRoleExtensions.OwnerValue ? "status-success" : "status-info")" style="align-self: flex-start; margin-bottom: 1rem;">
-                        @FormatRole(group.ManagerRole)
-                    </span>
+                    <div class="group-card-meta">
+                        <span class="status-badge platform-badge">
+                            @FormatPlatform(group.Platform)
+                        </span>
+                        <span class="status-badge @(group.ManagerRole == GroupManagerRoleExtensions.OwnerValue ? "status-success" : "status-info")">
+                            @FormatRole(group.ManagerRole)
+                        </span>
+                    </div>
                     <a href="/group/@group.Id" class="btn-gm btn-gm-primary" style="width: 100%; justify-content: center; margin-top: auto;">
                         Посмотреть игры →
                     </a>
@@ -81,6 +86,20 @@
         font-family: 'Courier New', monospace;
         margin-bottom: 1rem;
     }
+
+    .group-card-meta {
+        display: flex;
+        flex-wrap: wrap;
+        gap: 0.5rem;
+        align-items: center;
+        margin-bottom: 1rem;
+    }
+
+    .platform-badge {
+        background: rgba(88, 101, 242, 0.15);
+        color: #9ea8ff;
+        border-color: rgba(88, 101, 242, 0.35);
+    }
 </style>
 
 @code {
@@ -104,4 +123,7 @@
 
     private static string FormatRole(string role) =>
         GroupManagerRoleExtensions.FromDatabaseValue(role).ToDisplayName();
+
+    private static string FormatPlatform(string? platform) =>
+        string.Equals(platform, "Discord", StringComparison.OrdinalIgnoreCase) ? "Discord" : "Telegram";
 }

src/GmRelay.Web/Components/Pages/Profile.razor

@@ -0,0 +1,191 @@
+@page "/profile"
+@using Microsoft.AspNetCore.Authorization
+@using Microsoft.AspNetCore.Components.Authorization
+@using Microsoft.Extensions.Configuration
+@attribute [Authorize]
+@inject ISessionStore SessionStore
+@inject IConfiguration Configuration
+@inject NavigationManager Navigation
+
+<PageTitle>Профиль — GM-Relay</PageTitle>
+
+<div class="profile-container">
+    <h1 class="page-title">Профиль</h1>
+
+    @if (identities is null)
+    {
+        <p class="loading-text">Загрузка...</p>
+    }
+    else if (identities.Count == 0)
+    {
+        <div class="profile-card">
+            <p>Связанные аккаунты не найдены.</p>
+        </div>
+    }
+    else
+    {
+        <div class="profile-card">
+            <h2 class="section-title">Связанные аккаунты</h2>
+            <ul class="identity-list">
+                @foreach (var id in identities)
+                {
+                    <li class="identity-item">
+                        <div class="identity-info">
+                            <span class="identity-platform">@id.Platform</span>
+                            <span class="identity-name">@id.DisplayName</span>
+                        </div>
+                        @if (id.Platform != currentPlatform || id.ExternalUserId != currentExternalUserId)
+                        {
+                            <button class="btn btn-secondary btn-small"
+                                    @onclick="() => Unlink(id.Platform, id.ExternalUserId)"
+                                    disabled="@isUnlinking">
+                                Отвязать
+                            </button>
+                        }
+                        else
+                        {
+                            <span class="identity-badge">Текущий</span>
+                        }
+                    </li>
+                }
+            </ul>
+        </div>
+    }
+
+    <div class="profile-card">
+        <h2 class="section-title">Добавить аккаунт</h2>
+        @if (!HasLinkedPlatform("Discord"))
+        {
+            <a href="/auth/discord" class="btn btn-primary">
+                Привязать Discord
+            </a>
+        }
+        else
+        {
+            <p class="muted-text">Discord уже привязан.</p>
+        }
+
+        @if (currentPlatform == "Discord" && !HasLinkedPlatform("Telegram"))
+        {
+            var botUsername = Configuration["Telegram__BotUsername"] ?? Configuration["Telegram:BotUsername"];
+            if (!string.IsNullOrWhiteSpace(botUsername))
+            {
+                var authUrl = new Uri(new Uri(Navigation.BaseUri), "auth/telegram").ToString();
+                var widgetHtml = $"<script async src=\"https://telegram.org/js/telegram-widget.js?22\" data-telegram-login=\"{botUsername}\" data-size=\"large\" data-auth-url=\"{authUrl}\" data-request-access=\"write\"></script>";
+                <div class="telegram-widget-wrapper">
+                    @((MarkupString)widgetHtml)
+                </div>
+            }
+        }
+    </div>
+
+    @if (!string.IsNullOrWhiteSpace(errorMessage))
+    {
+        <div class="alert alert-error">@errorMessage</div>
+    }
+
+    @if (!string.IsNullOrWhiteSpace(successMessage))
+    {
+        <div class="alert alert-success">@successMessage</div>
+    }
+</div>
+
+@code {
+    private List<LinkedIdentity>? identities;
+    private string? currentPlatform;
+    private string? currentExternalUserId;
+    private bool isUnlinking;
+    private string? errorMessage;
+    private string? successMessage;
+
+    [CascadingParameter]
+    private Task<AuthenticationState>? AuthenticationStateTask { get; set; }
+
+    [SupplyParameterFromQuery]
+    public string? Linked { get; set; }
+
+    [SupplyParameterFromQuery(Name = "link_error")]
+    public string? LinkError { get; set; }
+
+    protected override async Task OnInitializedAsync()
+    {
+        if (AuthenticationStateTask is not null)
+        {
+            var authState = await AuthenticationStateTask;
+            var user = authState.User;
+            if (user.TryGetPlatformIdentity(out var plat, out var extId))
+            {
+                currentPlatform = plat;
+                currentExternalUserId = extId;
+            }
+        }
+
+        if (!string.IsNullOrWhiteSpace(Linked))
+        {
+            successMessage = $"{Linked} аккаунт успешно привязан!";
+        }
+
+        if (!string.IsNullOrWhiteSpace(LinkError))
+        {
+            errorMessage = $"Ошибка привязки: {Uri.UnescapeDataString(LinkError)}";
+        }
+
+        await LoadIdentities();
+    }
+
+    private async Task LoadIdentities()
+    {
+        try
+        {
+            if (currentPlatform is not null && currentExternalUserId is not null)
+            {
+                identities = await SessionStore.GetLinkedIdentitiesAsync(currentPlatform, currentExternalUserId);
+            }
+            else
+            {
+                identities = [];
+            }
+        }
+        catch (Exception ex)
+        {
+            errorMessage = $"Не удалось загрузить аккаунты: {ex.Message}";
+        }
+    }
+
+    private bool HasLinkedPlatform(string platform)
+    {
+        return identities?.Any(i => i.Platform == platform) ?? false;
+    }
+
+    private async Task Unlink(string platform, string externalUserId)
+    {
+        isUnlinking = true;
+        errorMessage = null;
+        successMessage = null;
+
+        try
+        {
+            if (currentPlatform is null || currentExternalUserId is null)
+            {
+                errorMessage = "Не удалось определить текущего пользователя.";
+                return;
+            }
+
+            await SessionStore.UnlinkIdentityAsync(currentPlatform, currentExternalUserId, platform, externalUserId);
+            successMessage = $"{platform} аккаунт отвязан.";
+            await LoadIdentities();
+        }
+        catch (InvalidOperationException ex)
+        {
+            errorMessage = $"Ошибка отвязки: {ex.Message}";
+        }
+        catch (Exception ex)
+        {
+            errorMessage = $"Ошибка отвязки: {ex.Message}";
+        }
+        finally
+        {
+            isUnlinking = false;
+        }
+    }
+}

src/GmRelay.Web/Program.cs

@@ -39,6 +39,7 @@ builder.AddNpgsqlDataSource("gmrelaydb");
 builder.Services.AddSingleton<TelegramAuthService>();
 builder.Services.Configure<DiscordOAuthOptions>(builder.Configuration.GetSection("Discord"));
 builder.Services.AddSingleton<DiscordAuthService>();
+builder.Services.AddSingleton<DiscordOAuthStateStore>();
 builder.Services.AddSingleton<ISessionStore, SessionService>();
 builder.Services.AddScoped<AuthorizedSessionService>();
 builder.Services.AddScoped<CalendarSubscriptionService>();
@@ -60,7 +61,7 @@ builder.Services.AddAuthentication(CookieAuthenticationDefaults.AuthenticationSc
         options.AccessDeniedPath = "/access-denied";
         options.Cookie.HttpOnly = true;
         options.Cookie.SecurePolicy = CookieSecurePolicy.Always;
-        options.Cookie.SameSite = SameSiteMode.Strict;
+        options.Cookie.SameSite = SameSiteMode.Lax;
         options.ExpireTimeSpan = TimeSpan.FromDays(7);
         options.SlidingExpiration = true;
     });
@@ -122,19 +123,39 @@ app.MapHealthChecks("/alive", new HealthCheckOptions
 });
 
 // Endpoint to handle Telegram Login callback
-app.MapGet("/auth/telegram", async (HttpContext context, TelegramAuthService authService) =>
+app.MapGet("/auth/telegram", async (HttpContext context, TelegramAuthService authService, ISessionStore sessionStore) =>
 {
-    if (authService.Verify(context.Request.Query, out var telegramId, out var name))
+    if (!authService.Verify(context.Request.Query, out var telegramId, out var name))
+        return Results.Redirect("/login?error=auth_failed");
+
+    await sessionStore.UpsertPlayerAsync("Telegram", telegramId.ToString(System.Globalization.CultureInfo.InvariantCulture), name, null);
+
+    // If already authenticated via another platform, link instead of replacing session
+    if (context.User.Identity?.IsAuthenticated == true
+        && context.User.TryGetPlatformIdentity(out var currentPlatform, out var currentExternalUserId)
+        && currentPlatform != "Telegram")
     {
-        var authProperties = new AuthenticationProperties { IsPersistent = true };
-        await context.SignInAsync(
-            CookieAuthenticationDefaults.AuthenticationScheme,
-            CreateTelegramPrincipal(telegramId, name),
-            authProperties);
-        return Results.Redirect("/");
+        try
+        {
+            // Always make Telegram the primary (it has the historical data/groups)
+            await sessionStore.LinkIdentityAsync(
+                "Telegram", telegramId.ToString(System.Globalization.CultureInfo.InvariantCulture),
+                currentPlatform, currentExternalUserId,
+                name);
+            return Results.Redirect("/profile?linked=telegram");
+        }
+        catch (InvalidOperationException ex)
+        {
+            return Results.Redirect($"/profile?link_error={Uri.EscapeDataString(ex.Message)}");
+        }
     }
 
-    return Results.Redirect("/login?error=auth_failed");
+    var authProperties = new AuthenticationProperties { IsPersistent = true };
+    await context.SignInAsync(
+        CookieAuthenticationDefaults.AuthenticationScheme,
+        CreateTelegramPrincipal(telegramId, name),
+        authProperties);
+    return Results.Redirect("/");
 });
 
 app.MapPost("/auth/telegram-webapp", async (
@@ -185,16 +206,9 @@ app.MapPost("/auth/logout", async (HttpContext context) =>
 });
 
 // Discord OAuth endpoints
-app.MapGet("/auth/discord", (HttpContext context, DiscordAuthService discordAuth) =>
+app.MapGet("/auth/discord", (DiscordAuthService discordAuth, DiscordOAuthStateStore stateStore) =>
 {
-    var state = Guid.NewGuid().ToString("N");
-    context.Response.Cookies.Append("__DiscordOAuthState", state, new CookieOptions
-    {
-        HttpOnly = true,
-        Secure = true,
-        SameSite = SameSiteMode.Strict,
-        MaxAge = TimeSpan.FromMinutes(5)
-    });
+    var state = stateStore.CreateState();
     var url = discordAuth.BuildAuthorizeUrl(state);
     return Results.Redirect(url);
 });
@@ -202,19 +216,15 @@ app.MapGet("/auth/discord", (HttpContext context, DiscordAuthService discordAuth
 app.MapGet("/auth/discord/callback", async (
     HttpContext context,
     DiscordAuthService discordAuth,
+    DiscordOAuthStateStore stateStore,
     ISessionStore sessionStore) =>
 {
     var code = context.Request.Query["code"].ToString();
     var state = context.Request.Query["state"].ToString();
-    var storedState = context.Request.Cookies["__DiscordOAuthState"];
-
-    context.Response.Cookies.Delete("__DiscordOAuthState");
 
     if (string.IsNullOrWhiteSpace(code) ||
         string.IsNullOrWhiteSpace(state) ||
-        !CryptographicOperations.FixedTimeEquals(
-            System.Text.Encoding.UTF8.GetBytes(state),
-            System.Text.Encoding.UTF8.GetBytes(storedState ?? string.Empty)))
+        !stateStore.ValidateAndRemove(state))
     {
         return Results.Redirect("/login?error=auth_failed");
     }
@@ -225,6 +235,25 @@ app.MapGet("/auth/discord/callback", async (
 
     await sessionStore.UpsertDiscordUserAsync(user.Id, user.DisplayName, user.AvatarUrl);
 
+    // If already authenticated via another platform, link instead of replacing session
+    if (context.User.Identity?.IsAuthenticated == true
+        && context.User.TryGetPlatformIdentity(out var currentPlatform, out var currentExternalUserId)
+        && currentPlatform != "Discord")
+    {
+        try
+        {
+            await sessionStore.LinkIdentityAsync(
+                currentPlatform, currentExternalUserId,
+                "Discord", user.Id,
+                user.DisplayName);
+            return Results.Redirect("/profile?linked=discord");
+        }
+        catch (InvalidOperationException ex)
+        {
+            return Results.Redirect($"/profile?link_error={Uri.EscapeDataString(ex.Message)}");
+        }
+    }
+
     var authProperties = new AuthenticationProperties { IsPersistent = true };
     await context.SignInAsync(
         CookieAuthenticationDefaults.AuthenticationScheme,
@@ -234,6 +263,38 @@ app.MapGet("/auth/discord/callback", async (
     return Results.Redirect("/");
 });
 
+// Identity linking API endpoints
+app.MapGet("/api/me/identities", async (
+    HttpContext context,
+    ISessionStore sessionStore) =>
+{
+    if (!context.User.TryGetPlatformIdentity(out var platform, out var externalUserId))
+        return Results.Unauthorized();
+
+    var identities = await sessionStore.GetLinkedIdentitiesAsync(platform, externalUserId);
+    return Results.Ok(identities);
+}).RequireAuthorization();
+
+app.MapDelete("/api/me/identities/{targetPlatform}/{targetExternalUserId}", async (
+    HttpContext context,
+    ISessionStore sessionStore,
+    string targetPlatform,
+    string targetExternalUserId) =>
+{
+    if (!context.User.TryGetPlatformIdentity(out var platform, out var externalUserId))
+        return Results.Unauthorized();
+
+    try
+    {
+        await sessionStore.UnlinkIdentityAsync(platform, externalUserId, targetPlatform, targetExternalUserId);
+        return Results.NoContent();
+    }
+    catch (InvalidOperationException ex)
+    {
+        return Results.BadRequest(new { error = ex.Message });
+    }
+}).RequireAuthorization();
+
 // Public calendar subscription endpoint (no auth required)
 app.MapGet("/calendar/{token}.ics", async (
     string token,

src/GmRelay.Web/Services/CalendarSubscriptionService.cs

@@ -12,7 +12,8 @@ public sealed class CalendarSubscriptionService(NpgsqlDataSource dataSource)
     public string GenerateToken() => Guid.NewGuid().ToString("N");
 
     public async Task<string> CreateSubscriptionAsync(
-        long userTelegramId,
+        string userPlatform,
+        string userExternalId,
         Guid? groupId,
         CalendarSubscriptionFilter filter,
         CancellationToken ct = default)
@@ -20,9 +21,9 @@ public sealed class CalendarSubscriptionService(NpgsqlDataSource dataSource)
         var token = GenerateToken();
         await using var connection = await dataSource.OpenConnectionAsync(ct);
         await connection.ExecuteAsync(
-            @"INSERT INTO calendar_subscriptions (id, token, user_telegram_id, group_id, filter_type, created_at, expires_at)
-              VALUES (gen_random_uuid(), @token, @userTelegramId, @groupId, @filterType, now(), NULL)",
-            new { token, userTelegramId, groupId, filterType = (int)filter });
+            @"INSERT INTO calendar_subscriptions (id, token, user_platform, user_external_id, group_id, filter_type, created_at, expires_at)
+              VALUES (gen_random_uuid(), @token, @userPlatform, @userExternalId, @groupId, @filterType, now(), NULL)",
+            new { token, userPlatform, userExternalId, groupId, filterType = (int)filter });
         return token;
     }
 
@@ -31,7 +32,7 @@ public sealed class CalendarSubscriptionService(NpgsqlDataSource dataSource)
         await using var connection = await dataSource.OpenConnectionAsync(ct);
 
         var subscription = await connection.QueryFirstOrDefaultAsync<SubscriptionRecord>(
-            @"SELECT id, user_telegram_id as UserTelegramId, group_id as GroupId, filter_type as FilterType
+            @"SELECT id, group_id as GroupId, filter_type as FilterType
               FROM calendar_subscriptions
               WHERE token = @token
                 AND (expires_at IS NULL OR expires_at > now())",
@@ -88,6 +89,6 @@ public sealed class CalendarSubscriptionService(NpgsqlDataSource dataSource)
         .Replace("\n", "\\n")
         .Replace("\r", "");
 
-    private sealed record SubscriptionRecord(Guid Id, long UserTelegramId, Guid? GroupId, int FilterType);
+    private sealed record SubscriptionRecord(Guid Id, Guid? GroupId, int FilterType);
     private sealed record CalendarSessionDto(Guid Id, string Title, DateTime ScheduledAt);
 }

src/GmRelay.Web/Services/DiscordAuthService.cs

@@ -5,7 +5,7 @@ using System.Text.Json.Serialization;
 
 namespace GmRelay.Web.Services;
 
-public sealed class DiscordAuthService(IHttpClientFactory httpClientFactory, IConfiguration configuration)
+public sealed class DiscordAuthService(IHttpClientFactory httpClientFactory, IConfiguration configuration, ILogger<DiscordAuthService> logger)
 {
     private readonly DiscordOAuthOptions _options = configuration.GetSection("Discord").Get<DiscordOAuthOptions>() ?? new DiscordOAuthOptions();
 
@@ -40,10 +40,14 @@ public sealed class DiscordAuthService(IHttpClientFactory httpClientFactory, ICo
         });
 
         var response = await client.PostAsync("https://discord.com/api/oauth2/token", content);
-        if (!response.IsSuccessStatusCode)
-            return null;
-
         var json = await response.Content.ReadAsStringAsync();
+        if (!response.IsSuccessStatusCode)
+        {
+            logger.LogError("Discord token exchange failed: {StatusCode} {Body}. client_id={ClientId}, redirect_uri={RedirectUri}",
+                (int)response.StatusCode, json, _options.ClientId, _options.RedirectUri);
+            return null;
+        }
+
         return JsonSerializer.Deserialize<DiscordTokenResponse>(json);
     }
 

src/GmRelay.Web/Services/DiscordOAuthStateStore.cs

@@ -0,0 +1,32 @@
+namespace GmRelay.Web.Services;
+
+public sealed class DiscordOAuthStateStore(ILogger<DiscordOAuthStateStore> logger)
+{
+    private readonly System.Collections.Concurrent.ConcurrentDictionary<string, DateTime> _states = new();
+
+    public string CreateState()
+    {
+        var state = Guid.NewGuid().ToString("N");
+        _states[state] = DateTime.UtcNow.AddMinutes(5);
+        logger.LogDebug("Discord OAuth state created: {State}", state);
+        return state;
+    }
+
+    public bool ValidateAndRemove(string state)
+    {
+        if (!_states.TryRemove(state, out var expiresAt))
+        {
+            logger.LogWarning("Discord OAuth state not found or already used: {State}", state);
+            return false;
+        }
+
+        if (DateTime.UtcNow > expiresAt)
+        {
+            logger.LogWarning("Discord OAuth state expired: {State}", state);
+            return false;
+        }
+
+        logger.LogDebug("Discord OAuth state validated: {State}", state);
+        return true;
+    }
+}

src/GmRelay.Web/Services/ISessionStore.cs

@@ -53,4 +53,19 @@ public interface ISessionStore
     Task LogSessionChangeAsync(Guid sessionId, string actorExternalUserId, string actorName, string changeType, string? oldValue, string? newValue);
     Task<List<SessionAuditLogEntry>> GetSessionHistoryAsync(Guid sessionId);
     Task UpsertDiscordUserAsync(string discordId, string displayName, string? avatarUrl);
+
+    // --- Identity linking (issue #35) ---
+    Task<Guid?> ResolveEffectivePlayerIdAsync(string platform, string externalUserId);
+    Task<List<LinkedIdentity>> GetLinkedIdentitiesAsync(string platform, string externalUserId);
+    Task LinkIdentityAsync(string currentPlatform, string currentExternalUserId, string targetPlatform, string targetExternalUserId, string? currentName);
+    Task UnlinkIdentityAsync(string currentPlatform, string currentExternalUserId, string targetPlatform, string targetExternalUserId);
+    Task UpsertPlayerAsync(string platform, string externalUserId, string displayName, string? avatarUrl);
 }
+
+public sealed record LinkedIdentity(
+    string Platform,
+    string ExternalUserId,
+    string DisplayName,
+    string? ExternalUsername,
+    string? AvatarUrl,
+    DateTime LinkedAt);

src/GmRelay.Web/Services/SessionService.cs

@@ -104,22 +104,45 @@ public sealed class SessionService(
     public async Task<List<WebGameGroup>> GetGroupsForUserAsync(string platform, string externalUserId)
     {
         await using var conn = await dataSource.OpenConnectionAsync();
+        var playerIds = await _ResolveLinkedPlayerIdsAsync(conn, platform, externalUserId);
+        if (playerIds.Length == 0)
+            return [];
+
         return (await conn.QueryAsync<WebGameGroup>(
             """
+            WITH visible_groups AS (
+                SELECT gm.group_id,
+                       CASE
+                           WHEN bool_or(gm.role = @OwnerRole) THEN @OwnerRole
+                           ELSE @CoGmRole
+                       END AS ManagerRole
+                FROM group_managers gm
+                WHERE gm.player_id = ANY(@PlayerIds)
+                GROUP BY gm.group_id
+            )
             SELECT g.id,
-                   g.telegram_chat_id AS TelegramChatId,
+                   g.external_group_id::BIGINT AS TelegramChatId,
                    g.external_group_id AS ExternalGroupId,
-                   g.name,
+                   COALESCE(NULLIF(g.name, g.external_group_id), latest_session.title, g.name) AS Name,
                    g.platform AS Platform,
-                   gm.role AS ManagerRole
-            FROM group_managers gm
-            JOIN players p ON p.id = gm.player_id
-            JOIN game_groups g ON g.id = gm.group_id
-            WHERE p.platform = @Platform
-              AND p.external_user_id = @ExternalUserId
+                   vg.ManagerRole
+            FROM visible_groups vg
+            JOIN game_groups g ON g.id = vg.group_id
+            LEFT JOIN LATERAL (
+                SELECT s.title
+                FROM sessions s
+                WHERE s.group_id = g.id
+                ORDER BY s.scheduled_at DESC
+                LIMIT 1
+            ) latest_session ON true
             ORDER BY g.name
             """,
-            new { Platform = platform, ExternalUserId = externalUserId })).ToList();
+            new
+            {
+                PlayerIds = playerIds,
+                OwnerRole = GroupManagerRoleExtensions.OwnerValue,
+                CoGmRole = GroupManagerRoleExtensions.CoGmValue
+            })).ToList();
     }
 
     public async Task<WebGameGroup?> GetGroupAsync(Guid groupId)
@@ -128,12 +151,19 @@ public sealed class SessionService(
         return await conn.QuerySingleOrDefaultAsync<WebGameGroup>(
             """
             SELECT g.id,
-                   g.telegram_chat_id AS TelegramChatId,
+                   g.external_group_id::BIGINT AS TelegramChatId,
                    g.external_group_id AS ExternalGroupId,
-                   g.name,
+                   COALESCE(NULLIF(g.name, g.external_group_id), latest_session.title, g.name) AS Name,
                    g.platform AS Platform,
                    @OwnerRole AS ManagerRole
             FROM game_groups g
+            LEFT JOIN LATERAL (
+                SELECT s.title
+                FROM sessions s
+                WHERE s.group_id = g.id
+                ORDER BY s.scheduled_at DESC
+                LIMIT 1
+            ) latest_session ON true
             WHERE g.id = @GroupId
             """,
             new { GroupId = groupId, OwnerRole = GroupManagerRoleExtensions.OwnerValue });
@@ -142,36 +172,40 @@ public sealed class SessionService(
     public async Task<bool> IsGroupManagerAsync(Guid groupId, string platform, string externalUserId)
     {
         await using var conn = await dataSource.OpenConnectionAsync();
+        var playerIds = await _ResolveLinkedPlayerIdsAsync(conn, platform, externalUserId);
+        if (playerIds.Length == 0)
+            return false;
+
         return await conn.ExecuteScalarAsync<bool>(
             """
             SELECT EXISTS (
                 SELECT 1
-                FROM group_managers gm
-                JOIN players p ON p.id = gm.player_id
-                WHERE gm.group_id = @GroupId
-                  AND p.platform = @Platform
-                  AND p.external_user_id = @ExternalUserId
+                FROM group_managers
+                WHERE group_id = @GroupId
+                  AND player_id = ANY(@PlayerIds)
             )
             """,
-            new { GroupId = groupId, Platform = platform, ExternalUserId = externalUserId });
+            new { GroupId = groupId, PlayerIds = playerIds });
     }
 
     public async Task<bool> IsGroupOwnerAsync(Guid groupId, string platform, string externalUserId)
     {
         await using var conn = await dataSource.OpenConnectionAsync();
+        var playerIds = await _ResolveLinkedPlayerIdsAsync(conn, platform, externalUserId);
+        if (playerIds.Length == 0)
+            return false;
+
         return await conn.ExecuteScalarAsync<bool>(
             """
             SELECT EXISTS (
                 SELECT 1
-                FROM group_managers gm
-                JOIN players p ON p.id = gm.player_id
-                WHERE gm.group_id = @GroupId
-                  AND p.platform = @Platform
-                  AND p.external_user_id = @ExternalUserId
-                  AND gm.role = @OwnerRole
+                FROM group_managers
+                WHERE group_id = @GroupId
+                  AND player_id = ANY(@PlayerIds)
+                  AND role = @OwnerRole
             )
             """,
-            new { GroupId = groupId, Platform = platform, ExternalUserId = externalUserId, OwnerRole = GroupManagerRoleExtensions.OwnerValue });
+            new { GroupId = groupId, PlayerIds = playerIds, OwnerRole = GroupManagerRoleExtensions.OwnerValue });
     }
 
     public async Task<List<WebGroupManager>> GetGroupManagersAsync(Guid groupId)
@@ -179,11 +213,11 @@ public sealed class SessionService(
         await using var conn = await dataSource.OpenConnectionAsync();
         return (await conn.QueryAsync<WebGroupManager>(
             """
-            SELECT COALESCE(p.telegram_id, 0) AS TelegramId,
-                   COALESCE(p.external_user_id, p.telegram_id::TEXT) AS ExternalUserId,
+            SELECT COALESCE(p.external_user_id::BIGINT, 0) AS TelegramId,
+                   p.external_user_id AS ExternalUserId,
                    p.display_name AS DisplayName,
-                   p.telegram_username AS TelegramUsername,
-                   COALESCE(p.external_username, p.telegram_username) AS ExternalUsername,
+                   p.external_username AS TelegramUsername,
+                   p.external_username AS ExternalUsername,
                    gm.role AS Role,
                    gm.created_at AS AddedAt
             FROM group_managers gm
@@ -204,7 +238,7 @@ public sealed class SessionService(
             SELECT
                 p.id AS PlayerId,
                 p.display_name AS DisplayName,
-                COALESCE(p.external_username, p.telegram_username) AS ExternalUsername,
+                p.external_username AS ExternalUsername,
                 COUNT(DISTINCT s.id) AS TotalSessions,
                 COUNT(DISTINCT CASE WHEN sp.rsvp_status = 'Confirmed' THEN s.id END) AS ConfirmedCount,
                 COUNT(DISTINCT CASE WHEN sp.rsvp_status = 'Declined' THEN s.id END) AS DeclinedCount,
@@ -223,7 +257,7 @@ public sealed class SessionService(
             WHERE s.group_id = @GroupId
               AND s.scheduled_at <= now()
               AND sp.is_gm = false
-            GROUP BY p.id, p.display_name, p.external_username, p.telegram_username
+            GROUP BY p.id, p.display_name, p.external_username
             ORDER BY AttendanceRate DESC, ConfirmedCount DESC
             """,
             new { GroupId = groupId })).ToList();
@@ -255,22 +289,6 @@ public sealed class SessionService(
         return entries.ToList();
     }
 
-    public async Task UpsertDiscordUserAsync(string discordId, string displayName, string? avatarUrl)
-    {
-        await using var conn = await dataSource.OpenConnectionAsync();
-        await conn.ExecuteAsync(
-            """
-            INSERT INTO players (display_name, platform, external_user_id, external_username)
-            VALUES (@DisplayName, 'Discord', @DiscordId, @DisplayName)
-            ON CONFLICT (platform, external_user_id)
-            WHERE platform IS NOT NULL AND external_user_id IS NOT NULL
-            DO UPDATE
-            SET display_name = EXCLUDED.display_name,
-                external_username = EXCLUDED.external_username
-            """,
-            new { DisplayName = displayName, DiscordId = discordId });
-    }
-
     public async Task AddGroupCoGmAsync(
         Guid groupId,
         string ownerPlatform, string ownerExternalUserId,
@@ -280,35 +298,16 @@ public sealed class SessionService(
         await using var conn = await dataSource.OpenConnectionAsync();
         await using var transaction = await conn.BeginTransactionAsync();
 
-        await conn.ExecuteAsync(
-            """
-            INSERT INTO players (display_name, telegram_username, platform, external_user_id, external_username)
-            VALUES (@DisplayName, @ExternalUsername, @Platform, @ExternalUserId, @ExternalUsername)
-            ON CONFLICT (platform, external_user_id)
-            WHERE platform IS NOT NULL AND external_user_id IS NOT NULL
-            DO UPDATE
-            SET display_name = EXCLUDED.display_name,
-                external_username = EXCLUDED.external_username
-            """,
-            new
-            {
-                DisplayName = displayName,
-                ExternalUsername = externalUsername,
-                Platform = coGmPlatform,
-                ExternalUserId = coGmExternalUserId
-            },
-            transaction);
+        var ownerPlayerId = await _ResolveEffectivePlayerIdAsync(conn, ownerPlatform, ownerExternalUserId);
+        if (ownerPlayerId is null)
+            throw new InvalidOperationException("Owner player not found.");
+
+        var coGmPlayerId = await _UpsertPlayerAndGetIdAsync(conn, coGmPlatform, coGmExternalUserId, displayName, externalUsername, transaction);
 
         await conn.ExecuteAsync(
             """
             INSERT INTO group_managers (group_id, player_id, role, added_by_player_id)
-            SELECT @GroupId,
-                   co_gm.id,
-                   @CoGmRole,
-                   owner_player.id
-            FROM players co_gm
-            LEFT JOIN players owner_player ON owner_player.platform = @OwnerPlatform AND owner_player.external_user_id = @OwnerExternalUserId
-            WHERE co_gm.platform = @CoGmPlatform AND co_gm.external_user_id = @CoGmExternalUserId
+            VALUES (@GroupId, @CoGmPlayerId, @CoGmRole, @OwnerPlayerId)
             ON CONFLICT (group_id, player_id) DO UPDATE
             SET role = CASE
                     WHEN group_managers.role = @OwnerRole THEN group_managers.role
@@ -319,10 +318,8 @@ public sealed class SessionService(
             new
             {
                 GroupId = groupId,
-                OwnerPlatform = ownerPlatform,
-                OwnerExternalUserId = ownerExternalUserId,
-                CoGmPlatform = coGmPlatform,
-                CoGmExternalUserId = coGmExternalUserId,
+                OwnerPlayerId = ownerPlayerId.Value,
+                CoGmPlayerId = coGmPlayerId,
                 OwnerRole = GroupManagerRoleExtensions.OwnerValue,
                 CoGmRole = GroupManagerRoleExtensions.CoGmValue
             },
@@ -334,21 +331,21 @@ public sealed class SessionService(
     public async Task RemoveGroupCoGmAsync(Guid groupId, string coGmPlatform, string coGmExternalUserId)
     {
         await using var conn = await dataSource.OpenConnectionAsync();
+        var coGmPlayerId = await _ResolveEffectivePlayerIdAsync(conn, coGmPlatform, coGmExternalUserId);
+        if (coGmPlayerId is null)
+            return;
+
         await conn.ExecuteAsync(
             """
-            DELETE FROM group_managers gm
-            USING players p
-            WHERE gm.player_id = p.id
-              AND gm.group_id = @GroupId
-              AND p.platform = @Platform
-              AND p.external_user_id = @ExternalUserId
-              AND gm.role = @CoGmRole
+            DELETE FROM group_managers
+            WHERE group_id = @GroupId
+              AND player_id = @PlayerId
+              AND role = @CoGmRole
             """,
             new
             {
                 GroupId = groupId,
-                Platform = coGmPlatform,
-                ExternalUserId = coGmExternalUserId,
+                PlayerId = coGmPlayerId.Value,
                 CoGmRole = GroupManagerRoleExtensions.CoGmValue
             });
     }
@@ -359,7 +356,7 @@ public sealed class SessionService(
         return (await conn.QueryAsync<WebSession>(
             @"SELECT s.id, s.group_id AS GroupId, s.title, s.scheduled_at AS ScheduledAt, s.status, s.join_link AS JoinLink,
                      s.batch_id AS BatchId, s.batch_message_id AS BatchMessageId,
-                     g.telegram_chat_id AS TelegramChatId,
+                     g.external_group_id::BIGINT AS TelegramChatId,
                      s.max_players AS MaxPlayers,
                      COALESCE(active_counts.count, 0)::int AS ActivePlayerCount,
                      COALESCE(waitlist_counts.count, 0)::int AS WaitlistedPlayerCount,
@@ -397,7 +394,7 @@ public sealed class SessionService(
         return await conn.QuerySingleOrDefaultAsync<WebSession>(
             @"SELECT s.id, s.group_id AS GroupId, s.title, s.scheduled_at AS ScheduledAt, s.status, s.join_link AS JoinLink,
                      s.batch_id AS BatchId, s.batch_message_id AS BatchMessageId,
-                     g.telegram_chat_id AS TelegramChatId,
+                     g.external_group_id::BIGINT AS TelegramChatId,
                      s.max_players AS MaxPlayers,
                      COALESCE(active_counts.count, 0)::int AS ActivePlayerCount,
                      COALESCE(waitlist_counts.count, 0)::int AS WaitlistedPlayerCount,
@@ -456,7 +453,7 @@ public sealed class SessionService(
         var oldSession = await conn.QuerySingleOrDefaultAsync<WebSession>(
             @"SELECT s.id, s.group_id AS GroupId, s.title, s.scheduled_at AS ScheduledAt, s.status, s.join_link AS JoinLink,
                      s.batch_id AS BatchId, s.batch_message_id AS BatchMessageId,
-                     g.telegram_chat_id AS TelegramChatId,
+                     g.external_group_id::BIGINT AS TelegramChatId,
                      s.max_players AS MaxPlayers,
                      0 AS ActivePlayerCount,
                      0 AS WaitlistedPlayerCount,
@@ -542,7 +539,7 @@ public sealed class SessionService(
         var session = await conn.QuerySingleOrDefaultAsync<WebSession>(
             @"SELECT s.id, s.group_id AS GroupId, s.title, s.scheduled_at AS ScheduledAt, s.status, s.join_link AS JoinLink,
                      s.batch_id AS BatchId, s.batch_message_id AS BatchMessageId,
-                     g.telegram_chat_id AS TelegramChatId,
+                     g.external_group_id::BIGINT AS TelegramChatId,
                      s.max_players AS MaxPlayers,
                      0 AS ActivePlayerCount,
                      0 AS WaitlistedPlayerCount,
@@ -641,11 +638,11 @@ public sealed class SessionService(
         return (await conn.QueryAsync<WebParticipant>(
             """
             SELECT sp.id AS Id,
-                   COALESCE(p.telegram_id, 0) AS TelegramId,
-                   COALESCE(p.external_user_id, p.telegram_id::TEXT) AS ExternalUserId,
+                   COALESCE(p.external_user_id::BIGINT, 0) AS TelegramId,
+                   p.external_user_id AS ExternalUserId,
                    p.display_name AS DisplayName,
-                   p.telegram_username AS TelegramUsername,
-                   COALESCE(p.external_username, p.telegram_username) AS ExternalUsername,
+                   p.external_username AS TelegramUsername,
+                   p.external_username AS ExternalUsername,
                    sp.rsvp_status AS RsvpStatus,
                    sp.registration_status AS RegistrationStatus,
                    sp.is_gm AS IsGm,
@@ -668,7 +665,7 @@ public sealed class SessionService(
         var session = await conn.QuerySingleOrDefaultAsync<WebSession>(
             @"SELECT s.id, s.group_id AS GroupId, s.title, s.scheduled_at AS ScheduledAt, s.status, s.join_link AS JoinLink,
                      s.batch_id AS BatchId, s.batch_message_id AS BatchMessageId,
-                     g.telegram_chat_id AS TelegramChatId,
+                     g.external_group_id::BIGINT AS TelegramChatId,
                      s.max_players AS MaxPlayers,
                      0 AS ActivePlayerCount,
                      0 AS WaitlistedPlayerCount,
@@ -689,9 +686,9 @@ public sealed class SessionService(
         var participant = await conn.QuerySingleOrDefaultAsync<WebParticipant>(
             """
             SELECT sp.id AS Id,
-                   p.telegram_id AS TelegramId,
+                   p.external_user_id::BIGINT AS TelegramId,
                    p.display_name AS DisplayName,
-                   p.telegram_username AS TelegramUsername,
+                   p.external_username AS TelegramUsername,
                    sp.rsvp_status AS RsvpStatus,
                    sp.registration_status AS RegistrationStatus,
                    sp.is_gm AS IsGm,
@@ -874,7 +871,7 @@ public sealed class SessionService(
                    s.status AS Status,
                    s.max_players AS MaxPlayers,
                    s.batch_message_id AS BatchMessageId,
-                   g.telegram_chat_id AS TelegramChatId,
+                   g.external_group_id::BIGINT AS TelegramChatId,
                    s.thread_id AS ThreadId,
                    s.topic_created_by_bot AS TopicCreatedByBot,
                    s.notification_mode AS NotificationMode
@@ -958,7 +955,7 @@ public sealed class SessionService(
                    s.status AS Status,
                    s.max_players AS MaxPlayers,
                    s.batch_message_id AS BatchMessageId,
-                   g.telegram_chat_id AS TelegramChatId,
+                   g.external_group_id::BIGINT AS TelegramChatId,
                    s.thread_id AS ThreadId,
                    s.topic_created_by_bot AS TopicCreatedByBot,
                    s.notification_mode AS NotificationMode
@@ -1180,7 +1177,7 @@ public sealed class SessionService(
         }
 
         var group = await conn.QuerySingleOrDefaultAsync<WebTemplateGroupDto>(
-            "SELECT telegram_chat_id AS TelegramChatId FROM game_groups WHERE id = @GroupId",
+            "SELECT external_group_id::BIGINT AS TelegramChatId FROM game_groups WHERE id = @GroupId",
             new { GroupId = groupId },
             transaction);
 
@@ -1251,7 +1248,7 @@ public sealed class SessionService(
     {
         return (await conn.QueryAsync<WebDirectNotificationRecipient>(
             """
-            SELECT p.telegram_id AS TelegramId,
+            SELECT p.external_user_id::BIGINT AS TelegramId,
                    p.display_name AS DisplayName
             FROM session_participants sp
             JOIN players p ON p.id = sp.player_id
@@ -1268,7 +1265,7 @@ public sealed class SessionService(
     {
         return (await conn.QueryAsync<WebDirectNotificationRecipient>(
             """
-            SELECT DISTINCT p.telegram_id AS TelegramId,
+            SELECT DISTINCT p.external_user_id::BIGINT AS TelegramId,
                             p.display_name AS DisplayName
             FROM session_participants sp
             JOIN players p ON p.id = sp.player_id
@@ -1321,7 +1318,7 @@ public sealed class SessionService(
             var participants = (await conn.QueryAsync<ParticipantBatchDto>(
                 @"SELECT sp.session_id AS SessionId,
                          p.display_name AS DisplayName,
-                         p.telegram_username AS TelegramUsername,
+                         p.external_username AS TelegramUsername,
                          sp.registration_status AS RegistrationStatus
                   FROM session_participants sp
                   JOIN players p ON sp.player_id = p.id
@@ -1358,7 +1355,7 @@ public sealed class SessionService(
                    s.group_id AS GroupId,
                    (array_agg(s.title ORDER BY s.scheduled_at))[1] AS Title,
                    (array_agg(s.join_link ORDER BY s.scheduled_at))[1] AS JoinLink,
-                   g.telegram_chat_id AS TelegramChatId,
+                   g.external_group_id::BIGINT AS TelegramChatId,
                    (array_agg(s.batch_message_id ORDER BY s.scheduled_at))[1] AS BatchMessageId,
                    (array_agg(s.thread_id ORDER BY s.scheduled_at))[1] AS ThreadId,
                    (array_agg(s.notification_mode ORDER BY s.scheduled_at))[1] AS NotificationMode
@@ -1366,9 +1363,280 @@ public sealed class SessionService(
             JOIN game_groups g ON g.id = s.group_id
             WHERE s.batch_id = @BatchId
               AND s.group_id = @GroupId
-            GROUP BY s.batch_id, s.group_id, g.telegram_chat_id
+            GROUP BY s.batch_id, s.group_id, g.external_group_id
             """,
             new { BatchId = batchId, GroupId = groupId },
             transaction);
     }
+
+    // --- Identity linking (issue #35) ---
+
+    public async Task<Guid?> ResolveEffectivePlayerIdAsync(string platform, string externalUserId)
+    {
+        await using var conn = await dataSource.OpenConnectionAsync();
+        return await _ResolveEffectivePlayerIdAsync(conn, platform, externalUserId);
+    }
+
+    public async Task<List<LinkedIdentity>> GetLinkedIdentitiesAsync(string platform, string externalUserId)
+    {
+        await using var conn = await dataSource.OpenConnectionAsync();
+
+        var effectiveId = await _ResolveEffectivePlayerIdAsync(conn, platform, externalUserId);
+        if (effectiveId is null)
+            return [];
+
+        return (await conn.QueryAsync<LinkedIdentity>(
+            """
+            SELECT p.platform AS Platform,
+                   p.external_user_id AS ExternalUserId,
+                   p.display_name AS DisplayName,
+                   p.external_username AS ExternalUsername,
+                   p.avatar_url AS AvatarUrl,
+                   COALESCE(pl.linked_at, p.created_at) AS LinkedAt
+            FROM players p
+            LEFT JOIN player_links pl ON pl.secondary_player_id = p.id
+            WHERE pl.primary_player_id = @EffectiveId
+               OR p.id = @EffectiveId
+            ORDER BY CASE WHEN p.id = @EffectiveId THEN 0 ELSE 1 END,
+                     p.platform
+            """,
+            new { EffectiveId = effectiveId.Value })).ToList();
+    }
+
+    public async Task LinkIdentityAsync(
+        string currentPlatform, string currentExternalUserId,
+        string targetPlatform, string targetExternalUserId,
+        string? currentName)
+    {
+        if (currentPlatform == targetPlatform && currentExternalUserId == targetExternalUserId)
+            throw new InvalidOperationException("Cannot link an identity to itself.");
+
+        await using var conn = await dataSource.OpenConnectionAsync();
+        await using var transaction = await conn.BeginTransactionAsync();
+
+        // Resolve current player (must exist — they are logged in)
+        var currentPlayerId = await _ResolvePlayerIdAsync(conn, currentPlatform, currentExternalUserId);
+        if (currentPlayerId is null)
+            throw new InvalidOperationException("Current player not found.");
+
+        // Upsert target player so it exists
+        var targetDisplayName = currentName ?? $"{targetPlatform} {targetExternalUserId}";
+        var targetPlayerId = await _UpsertPlayerAndGetIdAsync(conn, targetPlatform, targetExternalUserId, targetDisplayName, null, transaction);
+
+        // Check if target is already a primary of another link chain (conflict)
+        var targetIsPrimary = await conn.ExecuteScalarAsync<bool>(
+            """
+            SELECT EXISTS (
+                SELECT 1 FROM player_links WHERE primary_player_id = @TargetPlayerId
+            )
+            """,
+            new { TargetPlayerId = targetPlayerId }, transaction);
+
+        if (targetIsPrimary)
+        {
+            await _LogIdentityAuditAsync(conn, currentPlayerId.Value, "link_attempt_conflict",
+                targetPlatform, targetExternalUserId, currentPlayerId.Value, transaction);
+            await transaction.CommitAsync();
+            throw new InvalidOperationException("Target identity is already the primary account of another linked set.");
+        }
+
+        // Check if current is already a secondary (then their primary becomes the effective primary)
+        var currentPrimaryId = await conn.QuerySingleOrDefaultAsync<Guid?>(
+            """
+            SELECT primary_player_id
+            FROM player_links
+            WHERE secondary_player_id = @CurrentPlayerId
+            """,
+            new { CurrentPlayerId = currentPlayerId.Value }, transaction);
+
+        var effectiveCurrentPrimary = currentPrimaryId ?? currentPlayerId.Value;
+
+        // Check if target is already linked to someone else as secondary
+        var existingLink = await conn.QuerySingleOrDefaultAsync<Guid?>(
+            """
+            SELECT primary_player_id
+            FROM player_links
+            WHERE secondary_player_id = @TargetPlayerId
+            """,
+            new { TargetPlayerId = targetPlayerId }, transaction);
+
+        if (existingLink is not null && existingLink.Value != effectiveCurrentPrimary)
+        {
+            await _LogIdentityAuditAsync(conn, effectiveCurrentPrimary, "link_attempt_conflict",
+                targetPlatform, targetExternalUserId, currentPlayerId.Value, transaction);
+            await transaction.CommitAsync();
+            throw new InvalidOperationException("Target identity is already linked to another account.");
+        }
+
+        var effectivePrimary = currentPrimaryId ?? currentPlayerId.Value;
+
+        // Check if already linked
+        var alreadyLinked = await conn.ExecuteScalarAsync<bool>(
+            """
+            SELECT EXISTS (
+                SELECT 1 FROM player_links
+                WHERE primary_player_id = @EffectivePrimary AND secondary_player_id = @TargetPlayerId
+            )
+            """,
+            new { EffectivePrimary = effectivePrimary, TargetPlayerId = targetPlayerId }, transaction);
+
+        if (alreadyLinked)
+        {
+            await transaction.CommitAsync();
+            return; // Already linked, idempotent
+        }
+
+        await conn.ExecuteAsync(
+            """
+            INSERT INTO player_links (primary_player_id, secondary_player_id, linked_by_player_id)
+            VALUES (@PrimaryPlayerId, @SecondaryPlayerId, @LinkedByPlayerId)
+            """,
+            new
+            {
+                PrimaryPlayerId = effectivePrimary,
+                SecondaryPlayerId = targetPlayerId,
+                LinkedByPlayerId = currentPlayerId.Value
+            },
+            transaction);
+
+        await _LogIdentityAuditAsync(conn, effectivePrimary, "link",
+            targetPlatform, targetExternalUserId, currentPlayerId.Value, transaction);
+
+        await transaction.CommitAsync();
+    }
+
+    public async Task UnlinkIdentityAsync(
+        string currentPlatform, string currentExternalUserId,
+        string targetPlatform, string targetExternalUserId)
+    {
+        if (currentPlatform == targetPlatform && currentExternalUserId == targetExternalUserId)
+            throw new InvalidOperationException("Cannot unlink your own primary identity from itself.");
+
+        await using var conn = await dataSource.OpenConnectionAsync();
+        await using var transaction = await conn.BeginTransactionAsync();
+
+        var currentPlayerId = await _ResolvePlayerIdAsync(conn, currentPlatform, currentExternalUserId);
+        if (currentPlayerId is null)
+            throw new InvalidOperationException("Current player not found.");
+
+        var targetPlayerId = await _ResolvePlayerIdAsync(conn, targetPlatform, targetExternalUserId);
+        if (targetPlayerId is null)
+            throw new InvalidOperationException("Target identity not found.");
+
+        var effectivePrimary = await _ResolveEffectivePlayerIdAsync(conn, currentPlatform, currentExternalUserId);
+        if (effectivePrimary is null)
+            throw new InvalidOperationException("Effective primary not found.");
+
+        // Only the primary account owner (or the linked identity itself) can unlink
+        var rows = await conn.ExecuteAsync(
+            """
+            DELETE FROM player_links
+            WHERE primary_player_id = @EffectivePrimary
+              AND secondary_player_id = @TargetPlayerId
+            """,
+            new { EffectivePrimary = effectivePrimary.Value, TargetPlayerId = targetPlayerId.Value },
+            transaction);
+
+        if (rows == 0)
+        {
+            await transaction.RollbackAsync();
+            throw new InvalidOperationException("Identity is not linked to your account.");
+        }
+
+        await _LogIdentityAuditAsync(conn, effectivePrimary.Value, "unlink",
+            targetPlatform, targetExternalUserId, currentPlayerId.Value, transaction);
+
+        await transaction.CommitAsync();
+    }
+
+    public async Task UpsertPlayerAsync(string platform, string externalUserId, string displayName, string? avatarUrl)
+    {
+        await using var conn = await dataSource.OpenConnectionAsync();
+        await _UpsertPlayerAndGetIdAsync(conn, platform, externalUserId, displayName, avatarUrl, null);
+    }
+
+    public async Task UpsertDiscordUserAsync(string discordId, string displayName, string? avatarUrl)
+    {
+        await using var conn = await dataSource.OpenConnectionAsync();
+        await _UpsertPlayerAndGetIdAsync(conn, "Discord", discordId, displayName, avatarUrl, null);
+    }
+
+    // --- Private helpers ---
+
+    private static async Task<Guid?> _ResolvePlayerIdAsync(NpgsqlConnection conn, string platform, string externalUserId)
+    {
+        return await conn.QuerySingleOrDefaultAsync<Guid?>(
+            """
+            SELECT id FROM players
+            WHERE platform = @Platform AND external_user_id = @ExternalUserId
+            """,
+            new { Platform = platform, ExternalUserId = externalUserId });
+    }
+
+    private static async Task<Guid?> _ResolveEffectivePlayerIdAsync(NpgsqlConnection conn, string platform, string externalUserId)
+    {
+        var playerId = await _ResolvePlayerIdAsync(conn, platform, externalUserId);
+        if (playerId is null)
+            return null;
+
+        var primaryId = await conn.QuerySingleOrDefaultAsync<Guid?>(
+            """
+            SELECT primary_player_id FROM player_links
+            WHERE secondary_player_id = @PlayerId
+            """,
+            new { PlayerId = playerId.Value });
+
+        return primaryId ?? playerId;
+    }
+
+    private static async Task<Guid[]> _ResolveLinkedPlayerIdsAsync(NpgsqlConnection conn, string platform, string externalUserId)
+    {
+        var effectiveId = await _ResolveEffectivePlayerIdAsync(conn, platform, externalUserId);
+        if (effectiveId is null)
+            return [];
+
+        return (await conn.QueryAsync<Guid>(
+            """
+            SELECT @EffectiveId
+            UNION
+            SELECT secondary_player_id
+            FROM player_links
+            WHERE primary_player_id = @EffectiveId
+            """,
+            new { EffectiveId = effectiveId.Value })).ToArray();
+    }
+
+    private static async Task<Guid> _UpsertPlayerAndGetIdAsync(
+        NpgsqlConnection conn, string platform, string externalUserId,
+        string displayName, string? avatarUrl, NpgsqlTransaction? transaction)
+    {
+        return await conn.QuerySingleAsync<Guid>(
+            """
+            INSERT INTO players (display_name, platform, external_user_id, external_username, avatar_url)
+            VALUES (@DisplayName, @Platform, @ExternalUserId, @DisplayName, @AvatarUrl)
+            ON CONFLICT (platform, external_user_id)
+            WHERE platform IS NOT NULL AND external_user_id IS NOT NULL
+            DO UPDATE
+            SET display_name = EXCLUDED.display_name,
+                external_username = EXCLUDED.external_username,
+                avatar_url = COALESCE(EXCLUDED.avatar_url, players.avatar_url)
+            RETURNING id
+            """,
+            new { DisplayName = displayName, Platform = platform, ExternalUserId = externalUserId, AvatarUrl = avatarUrl },
+            transaction);
+    }
+
+    private static async Task _LogIdentityAuditAsync(
+        NpgsqlConnection conn, Guid playerId, string action,
+        string? targetPlatform, string? targetExternalUserId,
+        Guid? performedByPlayerId, NpgsqlTransaction? transaction)
+    {
+        await conn.ExecuteAsync(
+            """
+            INSERT INTO identity_audit_log (player_id, action, target_platform, target_external_user_id, performed_by_player_id)
+            VALUES (@PlayerId, @Action, @TargetPlatform, @TargetExternalUserId, @PerformedByPlayerId)
+            """,
+            new { PlayerId = playerId, Action = action, TargetPlatform = targetPlatform, TargetExternalUserId = targetExternalUserId, PerformedByPlayerId = performedByPlayerId },
+            transaction);
+    }
 }

tests/GmRelay.Bot.Tests/Discord/DiscordListSessionsHandlerTests.cs

@@ -33,7 +33,17 @@ public sealed class DiscordListSessionsHandlerTests
 
         Assert.Contains("platform = 'Discord'", handler, StringComparison.Ordinal);
         Assert.Contains("external_group_id = @GuildId", handler, StringComparison.Ordinal);
-        Assert.Contains("scheduled_at > NOW()", handler, StringComparison.Ordinal);
+        Assert.Contains("scheduled_at > now() - interval '4 hours'", handler, StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public void Handler_ShouldIncludeRecentlyStartedSessionsForCleanup()
+    {
+        var repoRoot = GetRepoRoot();
+        var handlerPath = Path.Combine(repoRoot, "src", "GmRelay.DiscordBot", "Features", "Sessions", "DiscordListSessionsHandler.cs");
+        var handler = File.ReadAllText(handlerPath);
+
+        Assert.Contains("now() - interval '4 hours'", handler, StringComparison.OrdinalIgnoreCase);
     }
 
     [Fact]
@@ -47,6 +57,17 @@ public sealed class DiscordListSessionsHandlerTests
         Assert.DoesNotContain("telegram_id", handler, StringComparison.Ordinal);
     }
 
+    [Fact]
+    public void Handler_ShouldExposeDeleteActionForManagers()
+    {
+        var repoRoot = GetRepoRoot();
+        var handlerPath = Path.Combine(repoRoot, "src", "GmRelay.DiscordBot", "Features", "Sessions", "DiscordListSessionsHandler.cs");
+        var handler = File.ReadAllText(handlerPath);
+
+        Assert.Contains("delete_session", handler, StringComparison.Ordinal);
+        Assert.Contains("CanManageSchedule", handler, StringComparison.Ordinal);
+    }
+
     [Fact]
     public void Command_ShouldExist()
     {
@@ -66,4 +87,18 @@ public sealed class DiscordListSessionsHandlerTests
         Assert.Contains("SlashCommand", command, StringComparison.Ordinal);
         Assert.Contains("listsessions", command, StringComparison.Ordinal);
     }
+
+    [Fact]
+    public void DeleteHandler_ShouldDeleteOnlySessionsFromTheInteractionGuild()
+    {
+        var repoRoot = GetRepoRoot();
+        var handlerPath = Path.Combine(repoRoot, "src", "GmRelay.DiscordBot", "Features", "Sessions", "DiscordDeleteSessionHandler.cs");
+
+        Assert.True(File.Exists(handlerPath), "DiscordDeleteSessionHandler should exist.");
+
+        var handler = File.ReadAllText(handlerPath);
+        Assert.Contains("DELETE FROM sessions", handler, StringComparison.Ordinal);
+        Assert.Contains("external_group_id = @GuildId", handler, StringComparison.Ordinal);
+        Assert.Contains("CanManageSchedule", handler, StringComparison.Ordinal);
+    }
 }

tests/GmRelay.Bot.Tests/Discord/DiscordNewSessionHandlerTests.cs

@@ -17,6 +17,17 @@ public sealed class DiscordNewSessionHandlerTests
 
     // --- Runtime tests for ParseTimeInput (static, no DB) ---
 
+    [Fact]
+    public void ParseTimeInput_ShouldTreatInputAsMoscowTime()
+    {
+        var result = DiscordNewSessionHandler.ParseTimeInput("2026-06-01 15:00");
+        Assert.True(result.IsSuccess);
+        // 15:00 MSK = 12:00 UTC
+        Assert.Equal(12, result.Value.Hour);
+        Assert.Equal(0, result.Value.Minute);
+        Assert.Equal(TimeSpan.Zero, result.Value.Offset);
+    }
+
     [Fact]
     public void ParseTimeInput_ShouldParseDiscordDateFormat()
     {
@@ -28,7 +39,8 @@ public sealed class DiscordNewSessionHandlerTests
         Assert.Equal(expected.Year, result.Value.Year);
         Assert.Equal(expected.Month, result.Value.Month);
         Assert.Equal(expected.Day, result.Value.Day);
-        Assert.Equal(19, result.Value.Hour);
+        // Input is treated as Moscow time; 19:30 MSK = 16:30 UTC
+        Assert.Equal(16, result.Value.Hour);
         Assert.Equal(30, result.Value.Minute);
     }
 
@@ -127,6 +139,18 @@ public sealed class DiscordNewSessionHandlerTests
         Assert.Contains("RollbackAsync", source, StringComparison.Ordinal);
     }
 
+    [Fact]
+    public void Handler_ShouldNotRollbackCommittedTransactionAfterPostCommitFailure()
+    {
+        var repoRoot = GetRepoRoot();
+        var handlerPath = Path.Combine(repoRoot, "src", "GmRelay.DiscordBot", "Features", "Sessions", "DiscordNewSessionHandler.cs");
+        var source = File.ReadAllText(handlerPath);
+
+        Assert.Contains("transactionCommitted = false", source, StringComparison.Ordinal);
+        Assert.Contains("transactionCommitted = true", source, StringComparison.Ordinal);
+        Assert.Contains("if (!transactionCommitted)", source, StringComparison.Ordinal);
+    }
+
     [Fact]
     public void Handler_ShouldRespectCancellationToken()
     {
@@ -145,7 +169,30 @@ public sealed class DiscordNewSessionHandlerTests
         var source = File.ReadAllText(commandPath);
 
         Assert.Contains("DiscordSessionBatchRenderer.Render", source, StringComparison.Ordinal);
-        Assert.Contains("WithEmbeds", source, StringComparison.Ordinal);
+        Assert.Contains("message.Embeds = embeds", source, StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public void Handler_ShouldLeaveScheduleMessageCreationToInteractionResponse()
+    {
+        var repoRoot = GetRepoRoot();
+        var handlerPath = Path.Combine(repoRoot, "src", "GmRelay.DiscordBot", "Features", "Sessions", "DiscordNewSessionHandler.cs");
+        var source = File.ReadAllText(handlerPath);
+
+        Assert.DoesNotContain("SendScheduleAsync", source, StringComparison.Ordinal);
+        Assert.DoesNotContain("PlatformScheduleMessage", source, StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public void Handler_ShouldStoreReadableDiscordGroupNameForWebCards()
+    {
+        var repoRoot = GetRepoRoot();
+        var handlerPath = Path.Combine(repoRoot, "src", "GmRelay.DiscordBot", "Features", "Sessions", "DiscordNewSessionHandler.cs");
+        var source = File.ReadAllText(handlerPath);
+
+        Assert.Contains("groupName", source, StringComparison.Ordinal);
+        Assert.Contains("displayGroupName", source, StringComparison.Ordinal);
+        Assert.Contains("VALUES (@GroupName, 'Discord'", source, StringComparison.Ordinal);
     }
 
     private static DateTimeOffset FutureDateAt1930()

tests/GmRelay.Bot.Tests/Discord/DiscordProjectStructureTests.cs

@@ -40,6 +40,7 @@ public sealed class DiscordProjectStructureTests
         Assert.Contains("GmRelay.Shared.csproj", project);
         Assert.DoesNotContain("Telegram.Bot", project);
         Assert.DoesNotContain("GmRelay.Bot.csproj", project);
+        Assert.Contains("Dapper.AOT", project);
     }
 
     [Fact]
@@ -61,7 +62,7 @@ public sealed class DiscordProjectStructureTests
         var prChecks = File.ReadAllText(Path.Combine(repoRoot, ".gitea", "workflows", "pr-checks.yml"));
         var deploy = File.ReadAllText(Path.Combine(repoRoot, ".gitea", "workflows", "deploy.yml"));
 
-        Assert.Contains("gmrelay-discord-bot:2.8.0", compose);
+        Assert.Contains("gmrelay-discord-bot:3.1.0", compose);
         Assert.Contains("Discord__Token=${DISCORD_BOT_TOKEN:?Set DISCORD_BOT_TOKEN in .env}", compose);
         Assert.Contains("src/GmRelay.DiscordBot/Dockerfile", deploy);
         Assert.Contains("DISCORD_BOT_TOKEN", deploy);
@@ -75,13 +76,13 @@ public sealed class DiscordProjectStructureTests
     {
         var repoRoot = GetRepoRoot();
 
-        Assert.Contains("<Version>2.8.0</Version>", File.ReadAllText(Path.Combine(repoRoot, "Directory.Build.props")));
-        Assert.Contains("VERSION: 2.8.0", File.ReadAllText(Path.Combine(repoRoot, ".gitea", "workflows", "deploy.yml")));
-        Assert.Contains("gmrelay-bot:2.8.0", File.ReadAllText(Path.Combine(repoRoot, "compose.yaml")));
-        Assert.Contains("gmrelay-web:2.8.0", File.ReadAllText(Path.Combine(repoRoot, "compose.yaml")));
-        Assert.Contains("gmrelay-discord-bot:2.8.0", File.ReadAllText(Path.Combine(repoRoot, "compose.yaml")));
+        Assert.Contains("<Version>3.1.0</Version>", File.ReadAllText(Path.Combine(repoRoot, "Directory.Build.props")));
+        Assert.Contains("VERSION: 3.1.0", File.ReadAllText(Path.Combine(repoRoot, ".gitea", "workflows", "deploy.yml")));
+        Assert.Contains("gmrelay-bot:3.1.0", File.ReadAllText(Path.Combine(repoRoot, "compose.yaml")));
+        Assert.Contains("gmrelay-web:3.1.0", File.ReadAllText(Path.Combine(repoRoot, "compose.yaml")));
+        Assert.Contains("gmrelay-discord-bot:3.1.0", File.ReadAllText(Path.Combine(repoRoot, "compose.yaml")));
         Assert.Contains(
-            "v2.8.0",
+            "v3.1.0",
             File.ReadAllText(Path.Combine(repoRoot, "src", "GmRelay.Web", "Components", "Layout", "NavMenu.razor")));
     }
 
@@ -94,6 +95,16 @@ public sealed class DiscordProjectStructureTests
         Assert.Contains("DISCORD_BOT_TOKEN", envExample);
     }
 
+    [Fact]
+    public void Readme_ShouldNotAskForUnusedDiscordBotClientId()
+    {
+        var repoRoot = GetRepoRoot();
+        var readme = File.ReadAllText(Path.Combine(repoRoot, "README.md"));
+
+        Assert.DoesNotContain("DISCORD_BOT_CLIENT_ID", readme);
+        Assert.Contains("DISCORD_CLIENT_ID", readme);
+    }
+
     [Fact]
     public void Compose_ShouldIncludeDiscordHealthcheck()
     {

tests/GmRelay.Bot.Tests/Discord/DiscordSessionInteractionModuleSourceTests.cs

@@ -21,6 +21,26 @@ public sealed class DiscordSessionInteractionModuleSourceTests
         Assert.Contains("MessageFlags.Ephemeral", source, StringComparison.Ordinal);
     }
 
+    [Fact]
+    public async Task Module_ShouldUpdateSourceScheduleMessageThroughComponentInteraction()
+    {
+        var source = await ReadRepositoryFileAsync("src/GmRelay.DiscordBot/Features/Sessions/DiscordSessionInteractionModule.cs");
+
+        Assert.Contains("InteractionCallback.DeferredModifyMessage", source, StringComparison.Ordinal);
+        Assert.Contains("DiscordSessionBatchRenderer.Render", source, StringComparison.Ordinal);
+        Assert.Contains("FollowupAsync", source, StringComparison.Ordinal);
+        Assert.Contains("CompleteScheduleUpdateResponseAsync", source, StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public async Task Module_ShouldRouteDeleteSessionButtons()
+    {
+        var source = await ReadRepositoryFileAsync("src/GmRelay.DiscordBot/Features/Sessions/DiscordSessionInteractionModule.cs");
+
+        Assert.Contains("[ComponentInteraction(\"delete_session\")]", source, StringComparison.Ordinal);
+        Assert.Contains("DiscordDeleteSessionHandler", source, StringComparison.Ordinal);
+    }
+
     [Fact]
     public async Task Module_ShouldRouteRsvpButtonsToNeutralHandler()
     {

tests/GmRelay.Bot.Tests/Discord/DiscordStartupTests.cs

@@ -1,5 +1,8 @@
 using System;
 using System.IO;
+using System.Reflection;
+using GmRelay.DiscordBot.Features.Sessions;
+using NetCord.Services.ApplicationCommands;
 
 namespace GmRelay.Bot.Tests.Discord;
 
@@ -47,6 +50,41 @@ public sealed class DiscordStartupTests
         Assert.Contains(".AddComponentInteractions", program);
         Assert.Contains(".AddGatewayHandlers", program);
         Assert.Contains("AddSlashCommand", program);
+        Assert.Contains("AddModules(typeof(Program).Assembly)", program);
+    }
+
+    [Theory]
+    [InlineData(typeof(DiscordNewSessionCommand), "newsession")]
+    [InlineData(typeof(DiscordListSessionsCommand), "listsessions")]
+    [InlineData(typeof(DiscordRescheduleCommand), "reschedule")]
+    public void DiscordSessionSlashCommands_ShouldBeDeclaredOnModuleMethods(Type moduleType, string commandName)
+    {
+        var executeMethod = moduleType.GetMethod("ExecuteAsync", BindingFlags.Instance | BindingFlags.Public);
+
+        Assert.NotNull(executeMethod);
+
+        var methodAttribute = Assert.Single(executeMethod.GetCustomAttributes<SlashCommandAttribute>(inherit: false));
+        var nameProperty = typeof(SlashCommandAttribute).GetProperty("Name")
+            ?? throw new InvalidOperationException("SlashCommandAttribute should expose command name.");
+
+        Assert.Equal(commandName, nameProperty.GetValue(methodAttribute));
+        Assert.Empty(moduleType.GetCustomAttributes<SlashCommandAttribute>(inherit: false));
+    }
+
+    [Fact]
+    public void DiscordSessionSlashCommands_ShouldBeDiscoverableByNetCordService()
+    {
+        var service = new ApplicationCommandService<SlashCommandContext>();
+
+        service.AddModules(typeof(DiscordNewSessionCommand).Assembly);
+
+        var commandNames = service.GetCommands()
+            .Select(command => command.Name)
+            .ToArray();
+
+        Assert.Contains("newsession", commandNames);
+        Assert.Contains("listsessions", commandNames);
+        Assert.Contains("reschedule", commandNames);
     }
 
     [Fact]

tests/GmRelay.Bot.Tests/Features/Sessions/CreateSession/PlatformNeutralSessionInteractionCommandTests.cs

@@ -13,6 +13,7 @@ public sealed class PlatformNeutralSessionInteractionCommandTests
         AssertProperty<JoinSessionCommand>("InteractionId", typeof(string));
         AssertProperty<JoinSessionCommand>("Group", typeof(PlatformGroup));
         AssertProperty<JoinSessionCommand>("ScheduleMessage", typeof(PlatformMessageRef));
+        AssertProperty<JoinSessionCommand>("DeferScheduleUpdate", typeof(bool));
         AssertNoTelegramSpecificProperties<JoinSessionCommand>();
     }
 
@@ -24,12 +25,29 @@ public sealed class PlatformNeutralSessionInteractionCommandTests
         AssertProperty<LeaveSessionCommand>("InteractionId", typeof(string));
         AssertProperty<LeaveSessionCommand>("Group", typeof(PlatformGroup));
         AssertProperty<LeaveSessionCommand>("ScheduleMessage", typeof(PlatformMessageRef));
+        AssertProperty<LeaveSessionCommand>("DeferScheduleUpdate", typeof(bool));
         AssertNoTelegramSpecificProperties<LeaveSessionCommand>();
     }
 
+    [Fact]
+    public void SessionInteractionResult_ShouldExposeReplyTextAndUpdatedView()
+    {
+        var resultType = typeof(JoinSessionCommand).Assembly.GetType(
+            "GmRelay.Shared.Features.Sessions.CreateSession.SessionInteractionResult");
+
+        Assert.NotNull(resultType);
+        AssertProperty(resultType, "ReplyText", typeof(string));
+        AssertProperty(resultType, "UpdatedView", typeof(GmRelay.Shared.Rendering.SessionBatchViewModel));
+    }
+
     private static void AssertProperty<T>(string name, Type expectedType)
     {
-        var property = Assert.Single(typeof(T).GetProperties(), property => property.Name == name);
+        AssertProperty(typeof(T), name, expectedType);
+    }
+
+    private static void AssertProperty(Type type, string name, Type expectedType)
+    {
+        var property = Assert.Single(type.GetProperties(), property => property.Name == name);
 
         Assert.Equal(expectedType, property.PropertyType);
     }

tests/GmRelay.Bot.Tests/Infrastructure/Database/PlatformIdentityMigrationTests.cs

@@ -91,6 +91,15 @@ public sealed class PlatformIdentityMigrationTests
         Assert.Contains("platform", service, StringComparison.Ordinal);
     }
 
+    [Fact]
+    public async Task WebSessionService_ShouldAuthorizeGroupsAcrossLinkedIdentities()
+    {
+        var service = await ReadRepositoryFileAsync("src/GmRelay.Web/Services/SessionService.cs");
+
+        Assert.Contains("_ResolveLinkedPlayerIdsAsync", service, StringComparison.Ordinal);
+        Assert.Contains("player_id = ANY(@PlayerIds)", service, StringComparison.Ordinal);
+    }
+
     [Fact]
     public async Task AttendanceStatsFunction_ShouldReferenceExternalUsername()
     {
@@ -108,6 +117,28 @@ public sealed class PlatformIdentityMigrationTests
         Assert.Contains("telegram_id DROP NOT NULL", migration, StringComparison.Ordinal);
     }
 
+    [Fact]
+    public async Task MigrationV024_ShouldDeprecateTelegramColumns()
+    {
+        var migration = await ReadRepositoryFileAsync("src/GmRelay.Bot/Migrations/V024__deprecate_telegram_columns.sql");
+
+        Assert.Contains("UPDATE players", migration, StringComparison.Ordinal);
+        Assert.Contains("UPDATE game_groups", migration, StringComparison.Ordinal);
+        Assert.Contains("DEPRECATED", migration, StringComparison.Ordinal);
+        Assert.Contains("calendar_subscriptions", migration, StringComparison.Ordinal);
+        Assert.Contains("user_platform", migration, StringComparison.Ordinal);
+        Assert.Contains("user_external_id", migration, StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public async Task MigrationV025_ShouldBackfillRescheduleProposals()
+    {
+        var migration = await ReadRepositoryFileAsync("src/GmRelay.Bot/Migrations/V025__reschedule_proposals_telegram_external.sql");
+
+        Assert.Contains("reschedule_proposals", migration, StringComparison.Ordinal);
+        Assert.Contains("proposed_by_external_user_id", migration, StringComparison.Ordinal);
+    }
+
     private static async Task<string> ReadRepositoryFileAsync(string relativePath)
     {
         var directory = new DirectoryInfo(AppContext.BaseDirectory);

tests/GmRelay.Bot.Tests/Infrastructure/Scheduling/SessionSchedulerServiceTests.cs

@@ -149,6 +149,68 @@ public sealed class SessionSchedulerServiceTests
         Assert.Null(ex);
     }
 
+    [Fact]
+    public async Task TickAsync_WhenHandlerThrows_BackoffsForDuration()
+    {
+        var sessionId = Guid.NewGuid();
+        var now = new DateTimeOffset(2026, 5, 15, 10, 0, 0, TimeSpan.Zero);
+        _clock.UtcNow = now;
+        _store.SessionsNeedingConfirmation = [sessionId];
+        _confirmationHandler.ThrowFor.Add(sessionId);
+
+        var sut = CreateSut();
+        await sut.TickAsync(CancellationToken.None);
+        Assert.Single(_confirmationHandler.Calls);
+
+        // Second tick immediately — should be backed off
+        await sut.TickAsync(CancellationToken.None);
+        Assert.Single(_confirmationHandler.Calls);
+    }
+
+    [Fact]
+    public async Task TickAsync_WhenHandlerThrows_AfterBackoffRetriesAgain()
+    {
+        var sessionId = Guid.NewGuid();
+        var now = new DateTimeOffset(2026, 5, 15, 10, 0, 0, TimeSpan.Zero);
+        _clock.UtcNow = now;
+        _store.SessionsNeedingConfirmation = [sessionId];
+        _confirmationHandler.ThrowFor.Add(sessionId);
+
+        var sut = CreateSut();
+        await sut.TickAsync(CancellationToken.None);
+        Assert.Single(_confirmationHandler.Calls);
+
+        // Advance clock past backoff duration (15 min)
+        _clock.UtcNow = now.AddMinutes(16);
+        await sut.TickAsync(CancellationToken.None);
+        Assert.Equal(2, _confirmationHandler.Calls.Count);
+    }
+
+    [Fact]
+    public async Task TickAsync_WhenHandlerSucceedsAfterBackoff_ClearsBackoff()
+    {
+        var sessionId = Guid.NewGuid();
+        var now = new DateTimeOffset(2026, 5, 15, 10, 0, 0, TimeSpan.Zero);
+        _clock.UtcNow = now;
+        _store.SessionsNeedingConfirmation = [sessionId];
+        _confirmationHandler.ThrowFor.Add(sessionId);
+
+        var sut = CreateSut();
+        await sut.TickAsync(CancellationToken.None);
+        Assert.Single(_confirmationHandler.Calls);
+
+        // Remove throw condition, advance past backoff
+        _confirmationHandler.ThrowFor.Remove(sessionId);
+        _clock.UtcNow = now.AddMinutes(16);
+        await sut.TickAsync(CancellationToken.None);
+        Assert.Equal(2, _confirmationHandler.Calls.Count);
+
+        // Next tick should still call because backoff was cleared on success
+        _clock.UtcNow = now.AddMinutes(17);
+        await sut.TickAsync(CancellationToken.None);
+        Assert.Equal(3, _confirmationHandler.Calls.Count);
+    }
+
     private sealed class FakeSendConfirmationHandler : ISendConfirmationHandler
     {
         public List<Guid> Calls { get; } = [];

tests/GmRelay.Bot.Tests/Rendering/DiscordSessionBatchRendererTests.cs

@@ -176,6 +176,32 @@ public sealed class DiscordSessionBatchRendererTests
         Assert.Equal("https://example.com/game", embeds[0].Url);
     }
 
+    [Fact]
+    public void Render_ShouldNormalizeBareDomainJoinLinkForEmbedUrl()
+    {
+        var sessionId = Guid.NewGuid();
+        var sessions = new[] { new SessionBatchDto(sessionId, DateTime.UtcNow, SessionStatus.Planned, 4, "mobaxterm.mobatek.net/game") };
+        var participants = Array.Empty<ParticipantBatchDto>();
+
+        var view = SessionBatchViewBuilder.Build("Test", sessions, participants);
+        var (embeds, _) = DiscordSessionBatchRenderer.Render(view);
+
+        Assert.Equal("https://mobaxterm.mobatek.net/game", embeds[0].Url);
+    }
+
+    [Fact]
+    public void Render_ShouldNotSetEmbedUrlWhenJoinLinkIsNotHttpUrl()
+    {
+        var sessionId = Guid.NewGuid();
+        var sessions = new[] { new SessionBatchDto(sessionId, DateTime.UtcNow, SessionStatus.Planned, 4, "test") };
+        var participants = Array.Empty<ParticipantBatchDto>();
+
+        var view = SessionBatchViewBuilder.Build("Test", sessions, participants);
+        var (embeds, _) = DiscordSessionBatchRenderer.Render(view);
+
+        Assert.Null(embeds[0].Url);
+    }
+
     [Fact]
     public void Render_ShouldEmbedCorrectFieldValues()
     {

tests/GmRelay.Bot.Tests/Web/AuthorizedSessionServiceTests.cs

@@ -1121,6 +1121,21 @@ public sealed class AuthorizedSessionServiceTests
         public Task UpsertDiscordUserAsync(string discordId, string displayName, string? avatarUrl) =>
             Task.CompletedTask;
 
+        public Task<Guid?> ResolveEffectivePlayerIdAsync(string platform, string externalUserId) =>
+            Task.FromResult<Guid?>(Guid.NewGuid());
+
+        public Task<List<LinkedIdentity>> GetLinkedIdentitiesAsync(string platform, string externalUserId) =>
+            Task.FromResult(new List<LinkedIdentity>());
+
+        public Task LinkIdentityAsync(string currentPlatform, string currentExternalUserId, string targetPlatform, string targetExternalUserId, string? currentName) =>
+            Task.CompletedTask;
+
+        public Task UnlinkIdentityAsync(string currentPlatform, string currentExternalUserId, string targetPlatform, string targetExternalUserId) =>
+            Task.CompletedTask;
+
+        public Task UpsertPlayerAsync(string platform, string externalUserId, string displayName, string? avatarUrl) =>
+            Task.CompletedTask;
+
         private bool IsManager(Guid groupId, long telegramId) =>
             IsOwner(groupId, telegramId) ||
             managers.Any(manager => manager.GroupId == groupId && manager.TelegramId == telegramId);

tests/GmRelay.Bot.Tests/Web/CookieAuthOptionsTests.cs

@@ -0,0 +1,34 @@
+using Microsoft.AspNetCore.Authentication.Cookies;
+using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Options;
+
+namespace GmRelay.Bot.Tests.Web;
+
+public sealed class CookieAuthOptionsTests
+{
+    [Fact]
+    public void CookieAuthOptions_ShouldUseLaxSameSite_ToAllowOAuthCallback()
+    {
+        // Arrange
+        var services = new ServiceCollection();
+        services.AddAuthentication(CookieAuthenticationDefaults.AuthenticationScheme)
+            .AddCookie(options =>
+            {
+                options.Cookie.HttpOnly = true;
+                options.Cookie.SecurePolicy = CookieSecurePolicy.Always;
+                options.Cookie.SameSite = SameSiteMode.Lax;
+                options.ExpireTimeSpan = TimeSpan.FromDays(7);
+                options.SlidingExpiration = true;
+            });
+
+        var provider = services.BuildServiceProvider();
+        var optionsMonitor = provider.GetRequiredService<IOptionsMonitor<CookieAuthenticationOptions>>();
+        var options = optionsMonitor.Get(CookieAuthenticationDefaults.AuthenticationScheme);
+
+        // Assert
+        Assert.Equal(SameSiteMode.Lax, options.Cookie.SameSite);
+        Assert.True(options.Cookie.HttpOnly);
+        Assert.Equal(CookieSecurePolicy.Always, options.Cookie.SecurePolicy);
+    }
+}

tests/GmRelay.Bot.Tests/Web/DiscordAuthServiceTests.cs

@@ -3,6 +3,7 @@ using System.Text.Json;
 using GmRelay.Web;
 using GmRelay.Web.Services;
 using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Logging.Abstractions;
 
 namespace GmRelay.Bot.Tests.Web;
 
@@ -20,7 +21,7 @@ public class DiscordAuthServiceTests
             })
             .Build();
 
-        var service = new DiscordAuthService(new TestHttpClientFactory(), config);
+        var service = new DiscordAuthService(new TestHttpClientFactory(), config, NullLogger<DiscordAuthService>.Instance);
         var url = service.BuildAuthorizeUrl("state123");
 
         Assert.Contains("client_id=12345", url);
@@ -33,7 +34,7 @@ public class DiscordAuthServiceTests
     public void BuildAuthorizeUrl_WithMissingConfig_ThrowsInvalidOperationException()
     {
         var config = new ConfigurationBuilder().Build();
-        var service = new DiscordAuthService(new TestHttpClientFactory(), config);
+        var service = new DiscordAuthService(new TestHttpClientFactory(), config, NullLogger<DiscordAuthService>.Instance);
 
         Assert.Throws<InvalidOperationException>(() => service.BuildAuthorizeUrl("state"));
     }
@@ -74,7 +75,7 @@ public class DiscordAuthServiceTests
             .Build();
 
         var factory = new TestHttpClientFactory(handler);
-        var service = new DiscordAuthService(factory, config);
+        var service = new DiscordAuthService(factory, config, NullLogger<DiscordAuthService>.Instance);
 
         var result = await service.ExchangeCodeAsync("valid_code");
 
@@ -102,7 +103,7 @@ public class DiscordAuthServiceTests
             .Build();
 
         var factory = new TestHttpClientFactory(handler);
-        var service = new DiscordAuthService(factory, config);
+        var service = new DiscordAuthService(factory, config, NullLogger<DiscordAuthService>.Instance);
 
         var result = await service.ExchangeCodeAsync("invalid_code");
 

tests/GmRelay.Bot.Tests/Web/HomePageSourceTests.cs

@@ -0,0 +1,35 @@
+namespace GmRelay.Bot.Tests.Web;
+
+public sealed class HomePageSourceTests
+{
+    [Fact]
+    public async Task HomePage_ShouldShowPlatformBadgeForGroups()
+    {
+        var source = await ReadRepositoryFileAsync("src/GmRelay.Web/Components/Pages/Home.razor");
+
+        Assert.Contains("platform-badge", source, StringComparison.Ordinal);
+        Assert.Contains("FormatPlatform", source, StringComparison.Ordinal);
+        Assert.Contains("group.Platform", source, StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public async Task SessionService_ShouldUseSessionTitleWhenDiscordGroupNameIsOnlyId()
+    {
+        var source = await ReadRepositoryFileAsync("src/GmRelay.Web/Services/SessionService.cs");
+
+        Assert.Contains("latest_session.title", source, StringComparison.Ordinal);
+        Assert.Contains("NULLIF(g.name, g.external_group_id)", source, StringComparison.Ordinal);
+    }
+
+    private static async Task<string> ReadRepositoryFileAsync(string relativePath)
+    {
+        var dir = AppContext.BaseDirectory;
+        while (!string.IsNullOrEmpty(dir) && !File.Exists(Path.Combine(dir, "Directory.Build.props")))
+        {
+            dir = Directory.GetParent(dir)?.FullName;
+        }
+
+        var repoRoot = dir ?? throw new InvalidOperationException("Could not find repo root");
+        return await File.ReadAllTextAsync(Path.Combine(repoRoot, relativePath));
+    }
+}

tests/GmRelay.Bot.Tests/packages.lock.json

@@ -392,8 +392,8 @@
           "Aspire.Npgsql": "[13.2.2, )",
           "Dapper": "[2.1.72, )",
           "Dapper.AOT": "[1.0.48, )",
-          "GmRelay.ServiceDefaults": "[2.5.0, )",
-          "GmRelay.Shared": "[2.5.0, )",
+          "GmRelay.ServiceDefaults": "[3.0.9, )",
+          "GmRelay.Shared": "[3.0.9, )",
           "Npgsql": "[10.0.2, )",
           "Telegram.Bot": "[22.9.5.3, )",
           "dbup-postgresql": "[7.0.1, )"
@@ -404,8 +404,9 @@
         "dependencies": {
           "Aspire.Npgsql": "[13.2.2, )",
           "Dapper": "[2.1.72, )",
-          "GmRelay.ServiceDefaults": "[2.5.0, )",
-          "GmRelay.Shared": "[2.5.0, )",
+          "Dapper.AOT": "[1.0.48, )",
+          "GmRelay.ServiceDefaults": "[3.0.9, )",
+          "GmRelay.Shared": "[3.0.9, )",
           "NetCord.Hosting": "[1.0.0-alpha.489, )",
           "NetCord.Hosting.Services": "[1.0.0-alpha.489, )",
           "NetCord.Services": "[1.0.0-alpha.489, )",
@@ -436,8 +437,8 @@
         "dependencies": {
           "Aspire.Npgsql": "[13.2.2, )",
           "Dapper": "[2.1.72, )",
-          "GmRelay.ServiceDefaults": "[2.5.0, )",
-          "GmRelay.Shared": "[2.5.0, )",
+          "GmRelay.ServiceDefaults": "[3.0.9, )",
+          "GmRelay.Shared": "[3.0.9, )",
           "Npgsql": "[10.0.2, )",
           "Telegram.Bot": "[22.9.6.1, )"
         }