diff --git a/.gitea/workflows/deploy.yml b/.gitea/workflows/deploy.yml
index ca3b1c9..dcc6a56 100644
--- a/.gitea/workflows/deploy.yml
+++ b/.gitea/workflows/deploy.yml
@@ -6,7 +6,7 @@ on:
       - main 
 
 env:
-  VERSION: 2.1.0
+  VERSION: 2.1.1
 
 jobs:
   # ЧАСТЬ 1: Собираем образы и кладем в Gitea (чтобы делиться с ребятами)
diff --git a/Directory.Build.props b/Directory.Build.props
index 60e9423..9a32501 100644
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -1,6 +1,6 @@
 <Project>
   <PropertyGroup>
-    <Version>2.1.0</Version>
+    <Version>2.1.1</Version>
     <TargetFramework>net10.0</TargetFramework>
     <LangVersion>preview</LangVersion>
     <Nullable>enable</Nullable>
diff --git a/compose.yaml b/compose.yaml
index 2fe9c78..988d092 100644
--- a/compose.yaml
+++ b/compose.yaml
@@ -49,7 +49,7 @@ services:
         crond -f
 
   bot:
-    image: git.codeanddice.ru/toutsu/gmrelay-bot:2.1.0
+    image: git.codeanddice.ru/toutsu/gmrelay-bot:2.1.1
     restart: always
     depends_on:
       db:
@@ -67,7 +67,7 @@ services:
       retries: 3
 
   web:
-    image: git.codeanddice.ru/toutsu/gmrelay-web:2.1.0
+    image: git.codeanddice.ru/toutsu/gmrelay-web:2.1.1
     restart: always
     depends_on:
       db:
diff --git a/docs/superpowers/plans/2026-05-18-platform-neutral-join-leave.md b/docs/superpowers/plans/2026-05-18-platform-neutral-join-leave.md
new file mode 100644
index 0000000..00367b0
--- /dev/null
+++ b/docs/superpowers/plans/2026-05-18-platform-neutral-join-leave.md
@@ -0,0 +1,599 @@
+# Platform-Neutral Join Leave Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Implement Gitea issue #25 by making join/leave session interactions use platform-neutral command models while preserving Telegram callback behavior, seat limits, and waitlist semantics.
+
+**Architecture:** Telegram callback routing remains in `UpdateRouter`, but it becomes an adapter that converts callback data into `PlatformUser`, `PlatformGroup`, and `PlatformMessageRef` values. `JoinSessionHandler` and `LeaveSessionHandler` operate on those neutral values, persist players by `(platform, external_user_id)`, and update schedules through `IPlatformMessenger`.
+
+**Tech Stack:** .NET 10, xUnit, Dapper, Npgsql, Gitea Actions.
+
+---
+
+## Issue Context
+
+- Issue: `#25 refactor: obobshchit JoinSession i LeaveSession pod platform-neutral interactions`
+- Labels: `area:bot`, `area:platform`, `area:shared`, `platform:multi`, `type:refactor`
+- Version bump: patch, `2.1.0` -> `2.1.1`. The issue is labeled refactor, not breaking; do not use a major bump without explicit approval.
+- Existing untracked file: `CLAUDE.md`; do not stage or modify it.
+
+## File Map
+
+- Create: `tests/GmRelay.Bot.Tests/Features/Sessions/CreateSession/PlatformNeutralSessionInteractionCommandTests.cs`
+  - Reflection tests proving join/leave command records expose neutral properties and no Telegram-specific identity/message fields.
+- Create: `tests/GmRelay.Bot.Tests/Features/Sessions/CreateSession/PlatformNeutralSessionInteractionSqlTests.cs`
+  - Source-level regression tests for handler SQL and messenger boundaries.
+- Modify: `tests/GmRelay.Bot.Tests/Infrastructure/Database/PlatformIdentityMigrationTests.cs`
+  - Add a migration test for nullable legacy `players.telegram_id`, required for non-Telegram player inserts.
+- Create: `src/GmRelay.Bot/Migrations/V017__allow_platform_neutral_players.sql`
+  - Drop `NOT NULL` from legacy Telegram-only player columns.
+- Modify: `src/GmRelay.Bot/Features/Sessions/CreateSession/JoinSessionHandler.cs`
+  - Change `JoinSessionCommand` to neutral properties and query/upsert players by platform identity.
+- Modify: `src/GmRelay.Bot/Features/Sessions/CreateSession/LeaveSessionHandler.cs`
+  - Change `LeaveSessionCommand` to neutral properties and find participants by platform identity.
+- Modify: `src/GmRelay.Bot/Infrastructure/Telegram/UpdateRouter.cs`
+  - Convert Telegram callback data into neutral command values using `TelegramPlatformIds`.
+- Modify: version files after implementation:
+  - `Directory.Build.props`
+  - `compose.yaml`
+  - `.gitea/workflows/deploy.yml`
+  - `src/GmRelay.Web/Components/Layout/NavMenu.razor`
+
+## Task 1: RED - Command Model Tests
+
+**Files:**
+- Create: `tests/GmRelay.Bot.Tests/Features/Sessions/CreateSession/PlatformNeutralSessionInteractionCommandTests.cs`
+
+- [ ] **Step 1: Write failing command-shape tests**
+
+```csharp
+using GmRelay.Bot.Features.Sessions.CreateSession;
+using GmRelay.Shared.Platform;
+
+namespace GmRelay.Bot.Tests.Features.Sessions.CreateSession;
+
+public sealed class PlatformNeutralSessionInteractionCommandTests
+{
+    [Fact]
+    public void JoinSessionCommand_ShouldExposePlatformNeutralInteractionContext()
+    {
+        AssertProperty<JoinSessionCommand>("SessionId", typeof(Guid));
+        AssertProperty<JoinSessionCommand>("User", typeof(PlatformUser));
+        AssertProperty<JoinSessionCommand>("InteractionId", typeof(string));
+        AssertProperty<JoinSessionCommand>("Group", typeof(PlatformGroup));
+        AssertProperty<JoinSessionCommand>("ScheduleMessage", typeof(PlatformMessageRef));
+        AssertNoTelegramSpecificProperties<JoinSessionCommand>();
+    }
+
+    [Fact]
+    public void LeaveSessionCommand_ShouldExposePlatformNeutralInteractionContext()
+    {
+        AssertProperty<LeaveSessionCommand>("SessionId", typeof(Guid));
+        AssertProperty<LeaveSessionCommand>("User", typeof(PlatformUser));
+        AssertProperty<LeaveSessionCommand>("InteractionId", typeof(string));
+        AssertProperty<LeaveSessionCommand>("Group", typeof(PlatformGroup));
+        AssertProperty<LeaveSessionCommand>("ScheduleMessage", typeof(PlatformMessageRef));
+        AssertNoTelegramSpecificProperties<LeaveSessionCommand>();
+    }
+
+    private static void AssertProperty<T>(string name, Type expectedType)
+    {
+        var property = Assert.Single(typeof(T).GetProperties(), property => property.Name == name);
+
+        Assert.Equal(expectedType, property.PropertyType);
+    }
+
+    private static void AssertNoTelegramSpecificProperties<T>()
+    {
+        var names = typeof(T).GetProperties().Select(property => property.Name).ToArray();
+
+        Assert.DoesNotContain(names, name => name.Contains("Telegram", StringComparison.Ordinal));
+        Assert.DoesNotContain("ChatId", names);
+        Assert.DoesNotContain("MessageId", names);
+        Assert.DoesNotContain("TelegramUserId", names);
+        Assert.DoesNotContain("TelegramUsername", names);
+    }
+}
+```
+
+- [ ] **Step 2: Verify RED**
+
+Run:
+
+```powershell
+dotnet test .\tests\GmRelay.Bot.Tests\GmRelay.Bot.Tests.csproj --filter PlatformNeutralSessionInteractionCommandTests
+```
+
+Expected: FAIL because `JoinSessionCommand` and `LeaveSessionCommand` still expose `TelegramUserId`, `ChatId`, and `MessageId`, and do not expose `User`, `Group`, or `ScheduleMessage`.
+
+## Task 2: RED - SQL and Boundary Tests
+
+**Files:**
+- Create: `tests/GmRelay.Bot.Tests/Features/Sessions/CreateSession/PlatformNeutralSessionInteractionSqlTests.cs`
+- Modify: `tests/GmRelay.Bot.Tests/Infrastructure/Database/PlatformIdentityMigrationTests.cs`
+
+- [ ] **Step 1: Write failing handler source tests**
+
+```csharp
+namespace GmRelay.Bot.Tests.Features.Sessions.CreateSession;
+
+public sealed class PlatformNeutralSessionInteractionSqlTests
+{
+    [Fact]
+    public async Task JoinSessionHandler_ShouldPersistPlayersByPlatformIdentity()
+    {
+        var handler = await ReadRepositoryFileAsync("src/GmRelay.Bot/Features/Sessions/CreateSession/JoinSessionHandler.cs");
+
+        Assert.Contains("platform, external_user_id", handler, StringComparison.Ordinal);
+        Assert.Contains("ON CONFLICT (platform, external_user_id)", handler, StringComparison.Ordinal);
+        Assert.Contains("ExternalUserId", handler, StringComparison.Ordinal);
+        Assert.Contains("ExternalUsername", handler, StringComparison.Ordinal);
+        Assert.DoesNotContain("TelegramPlatformIds.", handler, StringComparison.Ordinal);
+        Assert.DoesNotContain("command.TelegramUserId", handler, StringComparison.Ordinal);
+        Assert.DoesNotContain("command.TelegramUsername", handler, StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public async Task LeaveSessionHandler_ShouldFindParticipantsByPlatformIdentity()
+    {
+        var handler = await ReadRepositoryFileAsync("src/GmRelay.Bot/Features/Sessions/CreateSession/LeaveSessionHandler.cs");
+
+        Assert.Contains("p.platform = @Platform", handler, StringComparison.Ordinal);
+        Assert.Contains("p.external_user_id = @ExternalUserId", handler, StringComparison.Ordinal);
+        Assert.DoesNotContain("p.telegram_id = @TelegramUserId", handler, StringComparison.Ordinal);
+        Assert.DoesNotContain("TelegramPlatformIds.", handler, StringComparison.Ordinal);
+        Assert.DoesNotContain("command.TelegramUserId", handler, StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public async Task SessionInteractionHandlers_ShouldUpdateSchedulesThroughCommandMessageReference()
+    {
+        var joinHandler = await ReadRepositoryFileAsync("src/GmRelay.Bot/Features/Sessions/CreateSession/JoinSessionHandler.cs");
+        var leaveHandler = await ReadRepositoryFileAsync("src/GmRelay.Bot/Features/Sessions/CreateSession/LeaveSessionHandler.cs");
+
+        Assert.Contains("new PlatformScheduleMessage(", joinHandler, StringComparison.Ordinal);
+        Assert.Contains("command.Group", joinHandler, StringComparison.Ordinal);
+        Assert.Contains("command.ScheduleMessage", joinHandler, StringComparison.Ordinal);
+        Assert.Contains("new PlatformScheduleMessage(", leaveHandler, StringComparison.Ordinal);
+        Assert.Contains("command.Group", leaveHandler, StringComparison.Ordinal);
+        Assert.Contains("command.ScheduleMessage", leaveHandler, StringComparison.Ordinal);
+    }
+
+    private static async Task<string> ReadRepositoryFileAsync(string relativePath)
+    {
+        var directory = new DirectoryInfo(AppContext.BaseDirectory);
+        while (directory is not null)
+        {
+            var candidate = Path.Combine(directory.FullName, relativePath);
+            if (File.Exists(candidate))
+            {
+                return await File.ReadAllTextAsync(candidate);
+            }
+
+            directory = directory.Parent;
+        }
+
+        throw new FileNotFoundException($"Could not locate repository file '{relativePath}'.");
+    }
+}
+```
+
+- [ ] **Step 2: Add failing migration assertion**
+
+Append to `PlatformIdentityMigrationTests`:
+
+```csharp
+[Fact]
+public async Task MigrationV017_ShouldAllowPlayersWithoutLegacyTelegramId()
+{
+    var migration = await ReadRepositoryFileAsync("src/GmRelay.Bot/Migrations/V017__allow_platform_neutral_players.sql");
+
+    Assert.Contains("ALTER TABLE players", migration, StringComparison.Ordinal);
+    Assert.Contains("telegram_id DROP NOT NULL", migration, StringComparison.Ordinal);
+}
+```
+
+- [ ] **Step 3: Verify RED**
+
+Run:
+
+```powershell
+dotnet test .\tests\GmRelay.Bot.Tests\GmRelay.Bot.Tests.csproj --filter "PlatformNeutralSessionInteractionSqlTests|MigrationV017_ShouldAllowPlayersWithoutLegacyTelegramId"
+```
+
+Expected: FAIL because handlers still use Telegram-specific properties and the V017 migration file does not exist.
+
+## Task 3: GREEN - Add Migration
+
+**Files:**
+- Create: `src/GmRelay.Bot/Migrations/V017__allow_platform_neutral_players.sql`
+
+- [ ] **Step 1: Create the migration**
+
+```sql
+-- =============================================================
+-- V017: Allow platform-neutral players
+-- =============================================================
+-- Legacy Telegram identity columns remain for backward compatibility,
+-- but non-Telegram platform users do not have Telegram ids.
+-- =============================================================
+
+ALTER TABLE players
+    ALTER COLUMN telegram_id DROP NOT NULL;
+```
+
+- [ ] **Step 2: Verify migration test turns green**
+
+Run:
+
+```powershell
+dotnet test .\tests\GmRelay.Bot.Tests\GmRelay.Bot.Tests.csproj --filter MigrationV017_ShouldAllowPlayersWithoutLegacyTelegramId
+```
+
+Expected: PASS.
+
+## Task 4: GREEN - Refactor JoinSessionCommand and Handler
+
+**Files:**
+- Modify: `src/GmRelay.Bot/Features/Sessions/CreateSession/JoinSessionHandler.cs`
+
+- [ ] **Step 1: Replace command record**
+
+Replace the existing `JoinSessionCommand` declaration with:
+
+```csharp
+public sealed record JoinSessionCommand(
+    Guid SessionId,
+    PlatformUser User,
+    string InteractionId,
+    PlatformGroup Group,
+    PlatformMessageRef ScheduleMessage);
+```
+
+- [ ] **Step 2: Replace player upsert**
+
+Use platform identity parameters:
+
+```csharp
+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)
+      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
+    },
+    transaction);
+```
+
+Add `using System.Globalization;` at the top.
+
+- [ ] **Step 3: Update participant display query**
+
+Change the participant projection to prefer platform-neutral username:
+
+```sql
+COALESCE(p.external_username, p.telegram_username) as TelegramUsername
+```
+
+- [ ] **Step 4: Update schedule message and interaction reply usage**
+
+Use:
+
+```csharp
+await messenger.UpdateScheduleAsync(
+    new PlatformScheduleMessage(
+        command.Group,
+        view,
+        command.ScheduleMessage),
+    ct);
+```
+
+and:
+
+```csharp
+private Task AnswerAsync(string interactionId, string text, CancellationToken ct) =>
+    messenger.AnswerInteractionAsync(new PlatformInteractionReply(interactionId, text), ct);
+```
+
+Replace all `command.CallbackQueryId` calls with `command.InteractionId`.
+
+- [ ] **Step 5: Verify command and SQL tests for join**
+
+Run:
+
+```powershell
+dotnet test .\tests\GmRelay.Bot.Tests\GmRelay.Bot.Tests.csproj --filter "JoinSessionCommand_ShouldExposePlatformNeutralInteractionContext|JoinSessionHandler_ShouldPersistPlayersByPlatformIdentity"
+```
+
+Expected: PASS for join-focused tests.
+
+## Task 5: GREEN - Refactor LeaveSessionCommand and Handler
+
+**Files:**
+- Modify: `src/GmRelay.Bot/Features/Sessions/CreateSession/LeaveSessionHandler.cs`
+
+- [ ] **Step 1: Replace command record**
+
+Replace the existing `LeaveSessionCommand` declaration with:
+
+```csharp
+public sealed record LeaveSessionCommand(
+    Guid SessionId,
+    PlatformUser User,
+    string InteractionId,
+    PlatformGroup Group,
+    PlatformMessageRef ScheduleMessage);
+```
+
+- [ ] **Step 2: Replace participant lookup**
+
+Use platform identity instead of Telegram id:
+
+```csharp
+var platform = command.User.Platform.ToString();
+
+var participant = await connection.QuerySingleOrDefaultAsync<LeaveSessionParticipantDto>(
+    """
+    SELECT sp.id AS ParticipantRowId,
+           p.display_name AS DisplayName,
+           sp.registration_status AS RegistrationStatus
+    FROM session_participants sp
+    JOIN players p ON p.id = sp.player_id
+    WHERE sp.session_id = @SessionId
+      AND p.platform = @Platform
+      AND p.external_user_id = @ExternalUserId
+      AND sp.is_gm = false
+    FOR UPDATE OF sp
+    """,
+    new { command.SessionId, Platform = platform, command.User.ExternalUserId },
+    transaction);
+```
+
+- [ ] **Step 3: Update participant display query**
+
+Change the participant projection to:
+
+```sql
+COALESCE(p.external_username, p.telegram_username) AS TelegramUsername
+```
+
+- [ ] **Step 4: Update schedule message and interaction reply usage**
+
+Use:
+
+```csharp
+await messenger.UpdateScheduleAsync(
+    new PlatformScheduleMessage(
+        command.Group,
+        view,
+        command.ScheduleMessage),
+    ct);
+```
+
+Replace all `command.CallbackQueryId` calls with `command.InteractionId`.
+
+- [ ] **Step 5: Verify leave tests**
+
+Run:
+
+```powershell
+dotnet test .\tests\GmRelay.Bot.Tests\GmRelay.Bot.Tests.csproj --filter "LeaveSessionCommand_ShouldExposePlatformNeutralInteractionContext|LeaveSessionHandler_ShouldFindParticipantsByPlatformIdentity|SessionInteractionHandlers_ShouldUpdateSchedulesThroughCommandMessageReference"
+```
+
+Expected: PASS.
+
+## Task 6: GREEN - Convert Telegram Router to Neutral Commands
+
+**Files:**
+- Modify: `src/GmRelay.Bot/Infrastructure/Telegram/UpdateRouter.cs`
+
+- [ ] **Step 1: Add local conversion values in `HandleCallbackQueryAsync`**
+
+After parsing `action`, add:
+
+```csharp
+var user = TelegramPlatformIds.User(
+    query.From.Id,
+    query.From.FirstName + (string.IsNullOrEmpty(query.From.LastName) ? "" : $" {query.From.LastName}"),
+    query.From.Username);
+var group = TelegramPlatformIds.Group(message.Chat.Id, message.MessageThreadId, message.Chat.Title);
+var scheduleMessage = TelegramPlatformIds.Message(message.Chat.Id, message.MessageThreadId, message.MessageId);
+```
+
+- [ ] **Step 2: Update join command construction**
+
+```csharp
+var command = new JoinSessionCommand(
+    SessionId: joinSessionId,
+    User: user,
+    InteractionId: query.Id,
+    Group: group,
+    ScheduleMessage: scheduleMessage);
+```
+
+- [ ] **Step 3: Update leave command construction**
+
+```csharp
+var command = new LeaveSessionCommand(
+    SessionId: leaveSessionId,
+    User: user,
+    InteractionId: query.Id,
+    Group: group,
+    ScheduleMessage: scheduleMessage);
+```
+
+- [ ] **Step 4: Verify compile**
+
+Run:
+
+```powershell
+dotnet test .\tests\GmRelay.Bot.Tests\GmRelay.Bot.Tests.csproj --filter PlatformNeutralSessionInteractionCommandTests
+```
+
+Expected: PASS.
+
+## Task 7: REFACTOR - Clean Up and Full Test Pass
+
+**Files:**
+- Modify only files already listed if cleanup is needed.
+
+- [ ] **Step 1: Remove now-unused Telegram handler imports**
+
+Check `JoinSessionHandler.cs` and `LeaveSessionHandler.cs` for unused:
+
+```csharp
+using GmRelay.Bot.Infrastructure.Telegram;
+```
+
+Remove it from handlers if no longer needed.
+
+- [ ] **Step 2: Run focused tests**
+
+```powershell
+dotnet test .\tests\GmRelay.Bot.Tests\GmRelay.Bot.Tests.csproj --filter "PlatformNeutralSessionInteractionCommandTests|PlatformNeutralSessionInteractionSqlTests|PlatformIdentityMigrationTests"
+```
+
+Expected: PASS.
+
+- [ ] **Step 3: Run full test suite**
+
+```powershell
+dotnet test .\GM-Relay.slnx
+```
+
+Expected: PASS.
+
+- [ ] **Step 4: Build solution**
+
+```powershell
+dotnet build .\GM-Relay.slnx
+```
+
+Expected: PASS.
+
+## Task 8: Version Bump
+
+**Files:**
+- Modify: `Directory.Build.props`
+- Modify: `compose.yaml`
+- Modify: `.gitea/workflows/deploy.yml`
+- Modify: `src/GmRelay.Web/Components/Layout/NavMenu.razor`
+
+- [ ] **Step 1: Update version from `2.1.0` to `2.1.1`**
+
+Expected exact replacements:
+
+```xml
+<Version>2.1.1</Version>
+```
+
+```yaml
+VERSION: 2.1.1
+```
+
+```yaml
+image: git.codeanddice.ru/toutsu/gmrelay-bot:2.1.1
+image: git.codeanddice.ru/toutsu/gmrelay-web:2.1.1
+```
+
+```razor
+<div class="nav-version">v2.1.1</div>
+```
+
+- [ ] **Step 2: Verify synchronized versions**
+
+Run:
+
+```powershell
+rg "<Version>|image: git.codeanddice.ru/toutsu/gmrelay-|VERSION:|nav-version" Directory.Build.props compose.yaml .gitea\workflows\deploy.yml src\GmRelay.Web\Components\Layout\NavMenu.razor
+```
+
+Expected: all project image/app/deploy UI versions show `2.1.1`.
+
+## Task 9: PR, CI, Review, Merge, Deploy, Release
+
+**Files:**
+- No additional source changes expected.
+
+- [ ] **Step 1: Create branch after approval**
+
+```powershell
+git checkout -b refactor/issue-25-platform-neutral-join-leave
+```
+
+- [ ] **Step 2: Stage only intended files**
+
+```powershell
+git add docs/superpowers/plans/2026-05-18-platform-neutral-join-leave.md tests/GmRelay.Bot.Tests/Features/Sessions/CreateSession/PlatformNeutralSessionInteractionCommandTests.cs tests/GmRelay.Bot.Tests/Features/Sessions/CreateSession/PlatformNeutralSessionInteractionSqlTests.cs tests/GmRelay.Bot.Tests/Infrastructure/Database/PlatformIdentityMigrationTests.cs src/GmRelay.Bot/Migrations/V017__allow_platform_neutral_players.sql src/GmRelay.Bot/Features/Sessions/CreateSession/JoinSessionHandler.cs src/GmRelay.Bot/Features/Sessions/CreateSession/LeaveSessionHandler.cs src/GmRelay.Bot/Infrastructure/Telegram/UpdateRouter.cs Directory.Build.props compose.yaml .gitea/workflows/deploy.yml src/GmRelay.Web/Components/Layout/NavMenu.razor
+```
+
+- [ ] **Step 3: Commit**
+
+```powershell
+git commit -m "refactor: make session join leave platform-neutral"
+```
+
+- [ ] **Step 4: Push and create Gitea PR**
+
+```powershell
+git push -u origin refactor/issue-25-platform-neutral-join-leave
+```
+
+PR title:
+
+```text
+refactor: make session join leave platform-neutral
+```
+
+PR body:
+
+```markdown
+## Summary
+- Closes #25.
+- Converts join/leave session interaction commands from Telegram-specific fields to platform-neutral `PlatformUser`, `PlatformGroup`, and `PlatformMessageRef`.
+- Persists and looks up session participants by `(platform, external_user_id)`.
+- Keeps Telegram callback data and schedule update behavior intact.
+
+## Test plan
+- `dotnet test .\tests\GmRelay.Bot.Tests\GmRelay.Bot.Tests.csproj --filter "PlatformNeutralSessionInteractionCommandTests|PlatformNeutralSessionInteractionSqlTests|PlatformIdentityMigrationTests"`
+- `dotnet test .\GM-Relay.slnx`
+- `dotnet build .\GM-Relay.slnx`
+
+## Workflow
+- [ ] CI passes
+- [ ] Code review approved
+- [ ] Deployed
+- [ ] Release published
+```
+
+- [ ] **Step 5: Watch CI, request review, merge, deploy, release**
+
+Use Gitea MCP for PR creation, CI polling, review, merge, deploy monitoring, and release `v2.1.1`. Close issue #25 after release and add a comment linking the PR and release.
+
+## Self-Review
+
+- Spec coverage: issue scope is covered by neutral command records, Telegram adapter conversion, platform identity SQL, messenger-based schedule updates, and tests.
+- Placeholder scan: no `TBD`, `TODO`, or "fill later" steps remain.
+- Type consistency: commands consistently use `PlatformUser User`, `string InteractionId`, `PlatformGroup Group`, and `PlatformMessageRef ScheduleMessage`.
diff --git a/src/GmRelay.Bot/Features/Sessions/CreateSession/JoinSessionHandler.cs b/src/GmRelay.Bot/Features/Sessions/CreateSession/JoinSessionHandler.cs
index 1e23645..8301f8d 100644
--- a/src/GmRelay.Bot/Features/Sessions/CreateSession/JoinSessionHandler.cs
+++ b/src/GmRelay.Bot/Features/Sessions/CreateSession/JoinSessionHandler.cs
@@ -1,20 +1,18 @@
+using System.Globalization;
 using Dapper;
 using Npgsql;
 using GmRelay.Shared.Domain;
 using GmRelay.Shared.Platform;
 using GmRelay.Shared.Rendering;
-using GmRelay.Bot.Infrastructure.Telegram;
 
 namespace GmRelay.Bot.Features.Sessions.CreateSession;
 
 public sealed record JoinSessionCommand(
     Guid SessionId,
-    long TelegramUserId,
-    string DisplayName,
-    string? TelegramUsername,
-    string CallbackQueryId,
-    long ChatId,
-    int MessageId);
+    PlatformUser User,
+    string InteractionId,
+    PlatformGroup Group,
+    PlatformMessageRef ScheduleMessage);
 
 // DTOs for AOT compilation
 internal sealed record JoinSessionBatchDto(Guid BatchId, string Title, int? MaxPlayers);
@@ -33,17 +31,35 @@ public sealed class JoinSessionHandler(
         try
         {
             // 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 (@TgId, @Name, @Username, 'Telegram', @TgId::TEXT, @Username)
-                  ON CONFLICT (telegram_id) DO UPDATE
+                  VALUES (@LegacyTelegramId, @Name, @LegacyTelegramUsername, @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 = 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)
+                      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 { TgId = command.TelegramUserId, Name = command.DisplayName, Username = command.TelegramUsername },
+                new
+                {
+                    LegacyTelegramId = legacyTelegramId,
+                    Name = command.User.DisplayName,
+                    LegacyTelegramUsername = legacyTelegramUsername,
+                    Platform = platform,
+                    command.User.ExternalUserId,
+                    command.User.ExternalUsername
+                },
                 transaction);
 
             // 2. Блокируем сессию на время расчета мест, чтобы параллельные нажатия не переполнили состав.
@@ -58,7 +74,7 @@ public sealed class JoinSessionHandler(
             if (batchInfo is null)
             {
                 await transaction.RollbackAsync(ct);
-                await AnswerAsync(command.CallbackQueryId, "Сессия не найдена.", ct);
+                await AnswerAsync(command.InteractionId, "Сессия не найдена.", ct);
                 return;
             }
 
@@ -79,7 +95,7 @@ public sealed class JoinSessionHandler(
                 var alreadyText = existingRegistrationStatus == ParticipantRegistrationStatus.Waitlisted
                     ? "Вы уже в листе ожидания!"
                     : "Вы уже записаны!";
-                await AnswerAsync(command.CallbackQueryId, alreadyText, ct);
+                await AnswerAsync(command.InteractionId, alreadyText, ct);
                 return;
             }
 
@@ -113,7 +129,7 @@ public sealed class JoinSessionHandler(
             if (inserted == 0)
             {
                 await transaction.RollbackAsync(ct);
-                await AnswerAsync(command.CallbackQueryId, "Вы уже записаны!", ct);
+                await AnswerAsync(command.InteractionId, "Вы уже записаны!", ct);
                 return;
             }
 
@@ -128,7 +144,7 @@ public sealed class JoinSessionHandler(
             var batchParticipants = await connection.QueryAsync<ParticipantBatchDto>(
                 @"SELECT sp.session_id as SessionId,
                          p.display_name as DisplayName,
-                         p.telegram_username as TelegramUsername,
+                         COALESCE(p.external_username, p.telegram_username) as TelegramUsername,
                          sp.registration_status as RegistrationStatus
                   FROM session_participants sp
                   JOIN players p ON sp.player_id = p.id
@@ -144,15 +160,15 @@ public sealed class JoinSessionHandler(
             var view = SessionBatchViewBuilder.Build(batchInfo.Title, batchSessions.ToList(), batchParticipants.ToList());
             await messenger.UpdateScheduleAsync(
                 new PlatformScheduleMessage(
-                    TelegramPlatformIds.Group(command.ChatId),
+                    command.Group,
                     view,
-                    TelegramPlatformIds.Message(command.ChatId, threadId: null, command.MessageId)),
+                    command.ScheduleMessage),
                 ct);
 
             var callbackText = registrationStatus == ParticipantRegistrationStatus.Waitlisted
                 ? "Основной состав заполнен. Вы добавлены в лист ожидания."
                 : "Вы успешно записаны!";
-            await AnswerAsync(command.CallbackQueryId, callbackText, ct);
+            await AnswerAsync(command.InteractionId, callbackText, ct);
         }
         catch (Exception ex)
         {
@@ -165,10 +181,10 @@ public sealed class JoinSessionHandler(
             var errorText = transactionCommitted
                 ? "Регистрация сохранена, но не удалось обновить сообщение расписания."
                 : "Произошла ошибка при регистрации.";
-            await AnswerAsync(command.CallbackQueryId, errorText, ct);
+            await AnswerAsync(command.InteractionId, errorText, ct);
         }
     }
 
-    private Task AnswerAsync(string callbackQueryId, string text, CancellationToken ct) =>
-        messenger.AnswerInteractionAsync(new PlatformInteractionReply(callbackQueryId, text), ct);
+    private Task AnswerAsync(string interactionId, string text, CancellationToken ct) =>
+        messenger.AnswerInteractionAsync(new PlatformInteractionReply(interactionId, text), ct);
 }
diff --git a/src/GmRelay.Bot/Features/Sessions/CreateSession/LeaveSessionHandler.cs b/src/GmRelay.Bot/Features/Sessions/CreateSession/LeaveSessionHandler.cs
index 230e82c..872c5b9 100644
--- a/src/GmRelay.Bot/Features/Sessions/CreateSession/LeaveSessionHandler.cs
+++ b/src/GmRelay.Bot/Features/Sessions/CreateSession/LeaveSessionHandler.cs
@@ -3,16 +3,15 @@ using GmRelay.Shared.Domain;
 using GmRelay.Shared.Platform;
 using GmRelay.Shared.Rendering;
 using Npgsql;
-using GmRelay.Bot.Infrastructure.Telegram;
 
 namespace GmRelay.Bot.Features.Sessions.CreateSession;
 
 public sealed record LeaveSessionCommand(
     Guid SessionId,
-    long TelegramUserId,
-    string CallbackQueryId,
-    long ChatId,
-    int MessageId);
+    PlatformUser User,
+    string InteractionId,
+    PlatformGroup Group,
+    PlatformMessageRef ScheduleMessage);
 
 internal sealed record LeaveSessionInfoDto(string Title, Guid BatchId, string Status, int? MaxPlayers);
 internal sealed record LeaveSessionParticipantDto(Guid ParticipantRowId, string DisplayName, string RegistrationStatus);
@@ -47,17 +46,19 @@ public sealed class LeaveSessionHandler(
             if (session is null)
             {
                 await transaction.RollbackAsync(ct);
-                await AnswerAsync(command.CallbackQueryId, "Сессия не найдена.", ct);
+                await AnswerAsync(command.InteractionId, "Сессия не найдена.", ct);
                 return;
             }
 
             if (SessionStatus.IsCancelled(session.Status))
             {
                 await transaction.RollbackAsync(ct);
-                await AnswerAsync(command.CallbackQueryId, "Сессия уже отменена.", ct);
+                await AnswerAsync(command.InteractionId, "Сессия уже отменена.", ct);
                 return;
             }
 
+            var platform = command.User.Platform.ToString();
+
             var participant = await connection.QuerySingleOrDefaultAsync<LeaveSessionParticipantDto>(
                 """
                 SELECT sp.id AS ParticipantRowId,
@@ -66,17 +67,18 @@ public sealed class LeaveSessionHandler(
                 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 = @Platform
+                  AND p.external_user_id = @ExternalUserId
                   AND sp.is_gm = false
                 FOR UPDATE OF sp
                 """,
-                new { command.SessionId, command.TelegramUserId },
+                new { command.SessionId, Platform = platform, command.User.ExternalUserId },
                 transaction);
 
             if (participant is null)
             {
                 await transaction.RollbackAsync(ct);
-                await AnswerAsync(command.CallbackQueryId, "Вы не записаны на эту сессию.", ct);
+                await AnswerAsync(command.InteractionId, "Вы не записаны на эту сессию.", ct);
                 return;
             }
 
@@ -170,7 +172,7 @@ public sealed class LeaveSessionHandler(
                 """
                 SELECT sp.session_id AS SessionId,
                        p.display_name AS DisplayName,
-                       p.telegram_username AS TelegramUsername,
+                       COALESCE(p.external_username, p.telegram_username) AS TelegramUsername,
                        sp.registration_status AS RegistrationStatus
                 FROM session_participants sp
                 JOIN players p ON sp.player_id = p.id
@@ -187,9 +189,9 @@ public sealed class LeaveSessionHandler(
             var view = SessionBatchViewBuilder.Build(session.Title, batchSessions, batchParticipants);
             await messenger.UpdateScheduleAsync(
                 new PlatformScheduleMessage(
-                    TelegramPlatformIds.Group(command.ChatId),
+                    command.Group,
                     view,
-                    TelegramPlatformIds.Message(command.ChatId, threadId: null, command.MessageId)),
+                    command.ScheduleMessage),
                 ct);
 
             var callbackText = participant.RegistrationStatus == ParticipantRegistrationStatus.Waitlisted
@@ -198,7 +200,7 @@ public sealed class LeaveSessionHandler(
                     ? "Вы отписались от сессии."
                     : $"Вы отписались от сессии. Место получил(а) {promotedDisplayName}.";
 
-            await AnswerAsync(command.CallbackQueryId, callbackText, ct);
+            await AnswerAsync(command.InteractionId, callbackText, ct);
         }
         catch (Exception ex)
         {
@@ -211,10 +213,10 @@ public sealed class LeaveSessionHandler(
             var errorText = transactionCommitted
                 ? "Запись снята, но не удалось обновить сообщение расписания."
                 : "Произошла ошибка при отмене записи.";
-            await AnswerAsync(command.CallbackQueryId, errorText, ct);
+            await AnswerAsync(command.InteractionId, errorText, ct);
         }
     }
 
-    private Task AnswerAsync(string callbackQueryId, string text, CancellationToken ct) =>
-        messenger.AnswerInteractionAsync(new PlatformInteractionReply(callbackQueryId, text), ct);
+    private Task AnswerAsync(string interactionId, string text, CancellationToken ct) =>
+        messenger.AnswerInteractionAsync(new PlatformInteractionReply(interactionId, text), ct);
 }
diff --git a/src/GmRelay.Bot/Infrastructure/Telegram/UpdateRouter.cs b/src/GmRelay.Bot/Infrastructure/Telegram/UpdateRouter.cs
index 0538a55..1491842 100644
--- a/src/GmRelay.Bot/Infrastructure/Telegram/UpdateRouter.cs
+++ b/src/GmRelay.Bot/Infrastructure/Telegram/UpdateRouter.cs
@@ -69,17 +69,21 @@ public sealed class UpdateRouter(
 
         var parts = data.Split(':', 3);
         var action = parts[0];
+        var user = TelegramPlatformIds.User(
+            query.From.Id,
+            query.From.FirstName + (string.IsNullOrEmpty(query.From.LastName) ? "" : $" {query.From.LastName}"),
+            query.From.Username);
+        var group = TelegramPlatformIds.Group(message.Chat.Id, message.MessageThreadId, message.Chat.Title);
+        var scheduleMessage = TelegramPlatformIds.Message(message.Chat.Id, message.MessageThreadId, message.MessageId);
 
         if (action == "join_session" && parts.Length >= 2 && Guid.TryParse(parts[1], out var joinSessionId))
         {
             var command = new JoinSessionCommand(
                 SessionId: joinSessionId,
-                TelegramUserId: query.From.Id,
-                DisplayName: query.From.FirstName + (string.IsNullOrEmpty(query.From.LastName) ? "" : $" {query.From.LastName}"),
-                TelegramUsername: query.From.Username,
-                CallbackQueryId: query.Id,
-                ChatId: message.Chat.Id,
-                MessageId: message.MessageId);
+                User: user,
+                InteractionId: query.Id,
+                Group: group,
+                ScheduleMessage: scheduleMessage);
 
             await joinSessionHandler.HandleAsync(command, ct);
             return;
@@ -89,10 +93,10 @@ public sealed class UpdateRouter(
         {
             var command = new LeaveSessionCommand(
                 SessionId: leaveSessionId,
-                TelegramUserId: query.From.Id,
-                CallbackQueryId: query.Id,
-                ChatId: message.Chat.Id,
-                MessageId: message.MessageId);
+                User: user,
+                InteractionId: query.Id,
+                Group: group,
+                ScheduleMessage: scheduleMessage);
 
             await leaveSessionHandler.HandleAsync(command, ct);
             return;
diff --git a/src/GmRelay.Bot/Migrations/V017__allow_platform_neutral_players.sql b/src/GmRelay.Bot/Migrations/V017__allow_platform_neutral_players.sql
new file mode 100644
index 0000000..b7ca0dc
--- /dev/null
+++ b/src/GmRelay.Bot/Migrations/V017__allow_platform_neutral_players.sql
@@ -0,0 +1,9 @@
+-- =============================================================
+-- V017: Allow platform-neutral players
+-- =============================================================
+-- Legacy Telegram identity columns remain for backward compatibility,
+-- but non-Telegram platform users do not have Telegram ids.
+-- =============================================================
+
+ALTER TABLE players
+    ALTER COLUMN telegram_id DROP NOT NULL;
diff --git a/src/GmRelay.Web/Components/Layout/NavMenu.razor b/src/GmRelay.Web/Components/Layout/NavMenu.razor
index a54f6d4..55cf503 100644
--- a/src/GmRelay.Web/Components/Layout/NavMenu.razor
+++ b/src/GmRelay.Web/Components/Layout/NavMenu.razor
@@ -56,7 +56,7 @@
                     </button>
                 </form>
 
-                <div class="nav-version">v2.1.0</div>
+                <div class="nav-version">v2.1.1</div>
             </div>
         </Authorized>
         <NotAuthorized>
diff --git a/tests/GmRelay.Bot.Tests/Features/Sessions/CreateSession/PlatformNeutralSessionInteractionCommandTests.cs b/tests/GmRelay.Bot.Tests/Features/Sessions/CreateSession/PlatformNeutralSessionInteractionCommandTests.cs
new file mode 100644
index 0000000..b7e2049
--- /dev/null
+++ b/tests/GmRelay.Bot.Tests/Features/Sessions/CreateSession/PlatformNeutralSessionInteractionCommandTests.cs
@@ -0,0 +1,47 @@
+using GmRelay.Bot.Features.Sessions.CreateSession;
+using GmRelay.Shared.Platform;
+
+namespace GmRelay.Bot.Tests.Features.Sessions.CreateSession;
+
+public sealed class PlatformNeutralSessionInteractionCommandTests
+{
+    [Fact]
+    public void JoinSessionCommand_ShouldExposePlatformNeutralInteractionContext()
+    {
+        AssertProperty<JoinSessionCommand>("SessionId", typeof(Guid));
+        AssertProperty<JoinSessionCommand>("User", typeof(PlatformUser));
+        AssertProperty<JoinSessionCommand>("InteractionId", typeof(string));
+        AssertProperty<JoinSessionCommand>("Group", typeof(PlatformGroup));
+        AssertProperty<JoinSessionCommand>("ScheduleMessage", typeof(PlatformMessageRef));
+        AssertNoTelegramSpecificProperties<JoinSessionCommand>();
+    }
+
+    [Fact]
+    public void LeaveSessionCommand_ShouldExposePlatformNeutralInteractionContext()
+    {
+        AssertProperty<LeaveSessionCommand>("SessionId", typeof(Guid));
+        AssertProperty<LeaveSessionCommand>("User", typeof(PlatformUser));
+        AssertProperty<LeaveSessionCommand>("InteractionId", typeof(string));
+        AssertProperty<LeaveSessionCommand>("Group", typeof(PlatformGroup));
+        AssertProperty<LeaveSessionCommand>("ScheduleMessage", typeof(PlatformMessageRef));
+        AssertNoTelegramSpecificProperties<LeaveSessionCommand>();
+    }
+
+    private static void AssertProperty<T>(string name, Type expectedType)
+    {
+        var property = Assert.Single(typeof(T).GetProperties(), property => property.Name == name);
+
+        Assert.Equal(expectedType, property.PropertyType);
+    }
+
+    private static void AssertNoTelegramSpecificProperties<T>()
+    {
+        var names = typeof(T).GetProperties().Select(property => property.Name).ToArray();
+
+        Assert.DoesNotContain(names, name => name.Contains("Telegram", StringComparison.Ordinal));
+        Assert.DoesNotContain("ChatId", names);
+        Assert.DoesNotContain("MessageId", names);
+        Assert.DoesNotContain("TelegramUserId", names);
+        Assert.DoesNotContain("TelegramUsername", names);
+    }
+}
diff --git a/tests/GmRelay.Bot.Tests/Features/Sessions/CreateSession/PlatformNeutralSessionInteractionSqlTests.cs b/tests/GmRelay.Bot.Tests/Features/Sessions/CreateSession/PlatformNeutralSessionInteractionSqlTests.cs
new file mode 100644
index 0000000..71ef4aa
--- /dev/null
+++ b/tests/GmRelay.Bot.Tests/Features/Sessions/CreateSession/PlatformNeutralSessionInteractionSqlTests.cs
@@ -0,0 +1,61 @@
+namespace GmRelay.Bot.Tests.Features.Sessions.CreateSession;
+
+public sealed class PlatformNeutralSessionInteractionSqlTests
+{
+    [Fact]
+    public async Task JoinSessionHandler_ShouldPersistPlayersByPlatformIdentity()
+    {
+        var handler = await ReadRepositoryFileAsync("src/GmRelay.Bot/Features/Sessions/CreateSession/JoinSessionHandler.cs");
+
+        Assert.Contains("platform, external_user_id", handler, StringComparison.Ordinal);
+        Assert.Contains("ON CONFLICT (platform, external_user_id)", handler, StringComparison.Ordinal);
+        Assert.Contains("ExternalUserId", handler, StringComparison.Ordinal);
+        Assert.Contains("ExternalUsername", handler, StringComparison.Ordinal);
+        Assert.DoesNotContain("TelegramPlatformIds.", handler, StringComparison.Ordinal);
+        Assert.DoesNotContain("command.TelegramUserId", handler, StringComparison.Ordinal);
+        Assert.DoesNotContain("command.TelegramUsername", handler, StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public async Task LeaveSessionHandler_ShouldFindParticipantsByPlatformIdentity()
+    {
+        var handler = await ReadRepositoryFileAsync("src/GmRelay.Bot/Features/Sessions/CreateSession/LeaveSessionHandler.cs");
+
+        Assert.Contains("p.platform = @Platform", handler, StringComparison.Ordinal);
+        Assert.Contains("p.external_user_id = @ExternalUserId", handler, StringComparison.Ordinal);
+        Assert.DoesNotContain("p.telegram_id = @TelegramUserId", handler, StringComparison.Ordinal);
+        Assert.DoesNotContain("TelegramPlatformIds.", handler, StringComparison.Ordinal);
+        Assert.DoesNotContain("command.TelegramUserId", handler, StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public async Task SessionInteractionHandlers_ShouldUpdateSchedulesThroughCommandMessageReference()
+    {
+        var joinHandler = await ReadRepositoryFileAsync("src/GmRelay.Bot/Features/Sessions/CreateSession/JoinSessionHandler.cs");
+        var leaveHandler = await ReadRepositoryFileAsync("src/GmRelay.Bot/Features/Sessions/CreateSession/LeaveSessionHandler.cs");
+
+        Assert.Contains("new PlatformScheduleMessage(", joinHandler, StringComparison.Ordinal);
+        Assert.Contains("command.Group", joinHandler, StringComparison.Ordinal);
+        Assert.Contains("command.ScheduleMessage", joinHandler, StringComparison.Ordinal);
+        Assert.Contains("new PlatformScheduleMessage(", leaveHandler, StringComparison.Ordinal);
+        Assert.Contains("command.Group", leaveHandler, StringComparison.Ordinal);
+        Assert.Contains("command.ScheduleMessage", leaveHandler, StringComparison.Ordinal);
+    }
+
+    private static async Task<string> ReadRepositoryFileAsync(string relativePath)
+    {
+        var directory = new DirectoryInfo(AppContext.BaseDirectory);
+        while (directory is not null)
+        {
+            var candidate = Path.Combine(directory.FullName, relativePath);
+            if (File.Exists(candidate))
+            {
+                return await File.ReadAllTextAsync(candidate);
+            }
+
+            directory = directory.Parent;
+        }
+
+        throw new FileNotFoundException($"Could not locate repository file '{relativePath}'.");
+    }
+}
diff --git a/tests/GmRelay.Bot.Tests/Infrastructure/Database/PlatformIdentityMigrationTests.cs b/tests/GmRelay.Bot.Tests/Infrastructure/Database/PlatformIdentityMigrationTests.cs
index 483a5da..7a6f723 100644
--- a/tests/GmRelay.Bot.Tests/Infrastructure/Database/PlatformIdentityMigrationTests.cs
+++ b/tests/GmRelay.Bot.Tests/Infrastructure/Database/PlatformIdentityMigrationTests.cs
@@ -99,6 +99,15 @@ public sealed class PlatformIdentityMigrationTests
         Assert.Contains("external_username", statsMigration, StringComparison.Ordinal);
     }
 
+    [Fact]
+    public async Task MigrationV017_ShouldAllowPlayersWithoutLegacyTelegramId()
+    {
+        var migration = await ReadRepositoryFileAsync("src/GmRelay.Bot/Migrations/V017__allow_platform_neutral_players.sql");
+
+        Assert.Contains("ALTER TABLE players", migration, StringComparison.Ordinal);
+        Assert.Contains("telegram_id DROP NOT NULL", migration, StringComparison.Ordinal);
+    }
+
     private static async Task<string> ReadRepositoryFileAsync(string relativePath)
     {
         var directory = new DirectoryInfo(AppContext.BaseDirectory);