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.

tests/GmRelay.Bot.Tests/Features/Sessions/CreateSession/Wizard/UpdateRouterDelegationTests.cs

@@ -1,7 +1,7 @@
 using System.Threading;
 using System.Threading.Tasks;
-using GmRelay.Bot.Features.Sessions.CreateSession.Wizard;
 using GmRelay.Bot.Infrastructure.Telegram;
+using GmRelay.Shared.Features.Sessions.CreateSession.Wizard;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.Logging.Abstractions;
 using NSubstitute;
@@ -30,7 +30,7 @@ public sealed class UpdateRouterDelegationTests
         var draft = NewDraft(WizardStepNames.Title);
         drafts.Seed(draft);
 
-        var update = TextUpdate("Curse of Strahd", ownerId: draft.OwnerTelegramId);
+        var update = TextUpdate("Curse of Strahd", ownerId: long.Parse(draft.OwnerId, System.Globalization.CultureInfo.InvariantCulture));
 
         await sut.RouteAsync(update, CancellationToken.None);
 
@@ -49,7 +49,7 @@ public sealed class UpdateRouterDelegationTests
         // "wizard:cancel" — wizard owns the cancel callback. The router
         // delegates control-callbacks (resume/reset) but lets the wizard
         // handle wizard:* callbacks.
-        var update = CallbackUpdate(WizardCallbackData.Cancel(), ownerId: draft.OwnerTelegramId);
+        var update = CallbackUpdate(WizardCallbackData.Cancel(), ownerId: long.Parse(draft.OwnerId, System.Globalization.CultureInfo.InvariantCulture));
 
         await sut.RouteAsync(update, CancellationToken.None);