feat(discord): make /newsession identical to Telegram wizard

- Remove legacy DiscordNewSessionCommand/Handler and their tests.
- Rename /newsession-wizard to /newsession.
- Add shared pool capacity step before Format/Location.
- Render Format and Location in Discord wizard; Location uses a modal.
- Propagate Format, JoinLink and LocationAddress in BuildCommand.
- Publish created sessions through existing IPlatformMessenger pipeline.
- Update README, version bump to 3.11.1, sync compose/deploy/NavMenu.

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

@@ -46,7 +46,7 @@ public sealed class GameCreationWizardStepTransitionsTests
     }
 
     [Fact]
-    public async Task PoolSystemDuration_PreselectedButton_AdvancesToFormat()
+    public async Task PoolSystemDuration_PreselectedButton_AdvancesToCapacity()
     {
         var wizard = BuildWizard(out var drafts, out _);
         var payload = new WizardPayload
@@ -60,7 +60,7 @@ public sealed class GameCreationWizardStepTransitionsTests
         var data = WizardCallbackData.Choice(WizardStepNames.PoolSystemDuration, "Dnd5e:240");
         await wizard.HandleInteractionAsync(CallbackInteraction(data, ownerId: draft.OwnerId), draft, CancellationToken.None);
 
-        Assert.Equal(WizardStepNames.Format, draft.Step);
+        Assert.Equal(WizardStepNames.Capacity, draft.Step);
         using var doc = JsonDocument.Parse(draft.PayloadJson);
         var root = doc.RootElement;
         Assert.True(root.TryGetProperty("system", out var sys));
@@ -69,6 +69,53 @@ public sealed class GameCreationWizardStepTransitionsTests
         Assert.Equal(240, dur.GetInt32());
     }
 
+    [Fact]
+    public async Task PoolCapacity_Text_AdvancesToFormat_AndSetsMaxPlayers()
+    {
+        var wizard = BuildWizard(out var drafts, out _);
+        var payload = new WizardPayload
+        {
+            Type = WizardCreationType.Pool,
+            Title = "Pool",
+            System = "Dnd5e",
+            DurationMinutes = 240,
+        };
+        var draft = NewDraft(WizardStepNames.Capacity, payload);
+        drafts.Seed(draft);
+
+        await wizard.HandleInteractionAsync(TextInteraction("10", ownerId: draft.OwnerId), draft, CancellationToken.None);
+
+        Assert.Equal(WizardStepNames.Format, draft.Step);
+        using var doc = JsonDocument.Parse(draft.PayloadJson);
+        var root = doc.RootElement;
+        Assert.True(root.TryGetProperty("pool", out var pool));
+        Assert.True(pool.TryGetProperty("maxPlayers", out var maxPlayers));
+        Assert.Equal(10, maxPlayers.GetInt32());
+    }
+
+    [Theory]
+    [InlineData("waitlist:on")]
+    [InlineData("waitlist:off")]
+    public async Task Capacity_WithMaxPlayersAndWaitlist_AdvancesToFormat(string waitlistChoice)
+    {
+        var wizard = BuildWizard(out var drafts, out _);
+        var payload = new WizardPayload
+        {
+            Type = WizardCreationType.Single,
+            Title = "T",
+            System = "Dnd5e",
+            DurationMinutes = 240,
+            Single = new WizardSingleInput { ScheduledAt = DateTimeOffset.UtcNow.AddDays(1), MaxPlayers = 5 },
+        };
+        var draft = NewDraft(WizardStepNames.Capacity, payload);
+        drafts.Seed(draft);
+
+        var data = WizardCallbackData.Choice(WizardStepNames.Capacity, waitlistChoice);
+        await wizard.HandleInteractionAsync(CallbackInteraction(data, ownerId: draft.OwnerId), draft, CancellationToken.None);
+
+        Assert.Equal(WizardStepNames.Format, draft.Step);
+    }
+
     [Fact]
     public async Task NoLimitCapacityButton_AdvancesToVisibility_AndLeavesMaxPlayersNull()
     {