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/Discord/Wizard/DiscordWizardStepCapacityRenderTests.cs

@@ -56,6 +56,29 @@ public sealed class DiscordWizardStepCapacityRenderTests
             .Select(b => b.Label ?? string.Empty)
             .ToList();
 
+    [Fact]
+    public void RenderFormat_ContainsOnlineAndOfflineButtons()
+    {
+        var draft = new WizardDraft { Step = WizardStepNames.Format };
+        var render = DiscordWizardStep.Render(draft, new WizardPayload());
+
+        var labels = ExtractButtonLabels(render);
+        Assert.Contains(labels, l => l.Contains("Online", System.StringComparison.Ordinal));
+        Assert.Contains(labels, l => l.Contains("Offline", System.StringComparison.Ordinal));
+    }
+
+    [Theory]
+    [InlineData(WizardSessionFormat.Online, "🔗 Ссылка")]
+    [InlineData(WizardSessionFormat.Offline, "📍 Адрес")]
+    public void RenderLocation_ForFormat_OpensModalAndShowsPrompt(WizardSessionFormat format, string expectedTitle)
+    {
+        var draft = new WizardDraft { Step = WizardStepNames.Location };
+        var render = DiscordWizardStep.Render(draft, new WizardPayload { Format = format });
+
+        Assert.Equal(expectedTitle, render.EmbedTitle);
+        Assert.Equal(WizardStepNames.Location, render.OpenModalStep);
+    }
+
     private static System.Collections.Generic.List<ButtonProperties> ExtractButtons(
         DiscordWizardStep.DiscordWizardRender render) =>
         render.Components