refactor(wizard): move core to Shared, add IWizardMessenger contract (issue #112)

Moves the game-creation wizard state machine, view builder, and
platform-neutral contracts (callback data, step names, storage
exception, club option, step limits) from GmRelay.Bot to GmRelay.Shared.
Telegram continues to work through a new TelegramWizardMessenger
implementing IWizardMessenger and a WizardInteractionMapper that
converts Update → WizardInteraction. Wires the new platform column on
wizard_drafts (V032 migration) and switches chat/owner/thread/message
ids to TEXT so the same table can hold Discord snowflakes later.

- GameCreationWizard: now in Shared, takes IWizardMessenger +
  IWizardDraftRepository, dispatches on WizardInteraction.
- New IWizardMessenger contract with Edit/Send/Answer/GetOwnerClubs
  (returns string ids so Telegram longs and Discord snowflakes both
  fit).
- New WizardStepViewBuilder in Shared returns
  (text, IReadOnlyList<WizardAction>); TelegramWizardMessenger
  renders actions into InlineKeyboardMarkup via a new Bot-side
  ToInlineKeyboard helper.
- New WizardInteractionMapper in Bot (5-case test) converts Telegram
  Update to WizardInteraction.
- WizardDraft gains a Platform column; ChatId/MessageThreadId/OwnerId/
  DraftMessageId switched to string. V032 migrates existing rows and
  rebuilds the owner lookup index on (platform, owner_id).
- All existing wizard / create-session tests updated to the new
  contract (HandleInteractionAsync + WizardInteraction). Wizard
  callback-data format preserved.
- dotnet build clean, dotnet format --verify-no-changes clean, all
  101 wizard tests pass.

src/GmRelay.Shared/Features/Sessions/CreateSession/Wizard/WizardDraftRepository.cs

@@ -8,14 +8,14 @@ namespace GmRelay.Shared.Features.Sessions.CreateSession.Wizard;
 
 public sealed class WizardDraftRepository(NpgsqlDataSource dataSource) : IWizardDraftRepository
 {
-    public async Task<WizardDraft?> GetActiveAsync(
-        long chatId, int? messageThreadId, long ownerTelegramId, CancellationToken ct)
+    public async Task<WizardDraft?> GetActiveAsync(string platform, string ownerId, CancellationToken ct)
     {
         const string sql = """
             SELECT id              AS Id,
                    chat_id         AS ChatId,
                    message_thread_id AS MessageThreadId,
-                   owner_telegram_id AS OwnerTelegramId,
+                   owner_id        AS OwnerId,
+                   platform        AS Platform,
                    step            AS Step,
                    payload::text   AS PayloadJson,
                    draft_message_id AS DraftMessageId,
@@ -23,17 +23,18 @@ public sealed class WizardDraftRepository(NpgsqlDataSource dataSource) : IWizard
                    updated_at      AS UpdatedAt,
                    expires_at      AS ExpiresAt
             FROM wizard_drafts
-            WHERE chat_id = @ChatId
-              AND (message_thread_id = @ThreadId OR (@ThreadId IS NULL AND message_thread_id IS NULL))
-              AND owner_telegram_id = @OwnerId
+            WHERE platform = @Platform
+              AND owner_id = @OwnerId
               AND expires_at > NOW()
+            ORDER BY updated_at DESC
             LIMIT 1
             """;
 
         await using var connection = await dataSource.OpenConnectionAsync(ct);
         return await connection.QuerySingleOrDefaultAsync<WizardDraft>(
-            new CommandDefinition(sql,
-                new { ChatId = chatId, ThreadId = messageThreadId, OwnerId = ownerTelegramId },
+            new CommandDefinition(
+                sql,
+                new { Platform = platform, OwnerId = ownerId },
                 cancellationToken: ct));
     }
 
@@ -41,9 +42,9 @@ public sealed class WizardDraftRepository(NpgsqlDataSource dataSource) : IWizard
     {
         const string sql = """
             INSERT INTO wizard_drafts
-                (id, chat_id, message_thread_id, owner_telegram_id, step, payload, draft_message_id, created_at, updated_at, expires_at)
+                (id, chat_id, message_thread_id, owner_id, platform, step, payload, draft_message_id, created_at, updated_at, expires_at)
             VALUES
-                (@Id, @ChatId, @MessageThreadId, @OwnerTelegramId, @Step, @PayloadJson::jsonb, @DraftMessageId, @CreatedAt, @UpdatedAt, @ExpiresAt)
+                (@Id, @ChatId, @MessageThreadId, @OwnerId, @Platform, @Step, @PayloadJson::jsonb, @DraftMessageId, @CreatedAt, @UpdatedAt, @ExpiresAt)
             ON CONFLICT (id) DO UPDATE
                 SET step = EXCLUDED.step,
                     payload = EXCLUDED.payload,