feat(web): add private club showcases with membership flow (v3.7.0)

Implements Issue #110: game masters can now publish sessions
exclusively to a club's private showcase, gated behind a
member application and approval flow. Adds a 4-state
publication_mode (None/Catalog/ClubOnly/Both) replacing the
binary is_public, plus a club_memberships table with
Pending/Active/Rejected/Left lifecycle and partial unique
index ensuring a single Active row per (group, player).

Highlights
- V030 migration: club_memberships, publication_mode, drop
  is_public, recreate partial indexes, portfolio_games gains
  publication_mode.
- PublicationMode enum + extensions in GmRelay.Shared.
- ISessionStore gains 12 membership/showcase methods;
  AuthorizedMembershipService owns the membership flow with
  GM-only approve/reject authorization.
- PublicClub / PublicMasterProfile / PublicSession: member-
  aware queries (ClubOnly visible only to Active members).
- New pages: MyClubMemberships (/profile/memberships) and
  ClubApplications (/group/{id}/applications).
- GroupDetails and EditSession switch from a bool toggle to
  a 4-state publication_mode selector.
- NavMenu adds Moji kluby, PublicLayout adds Kluby.

Tests: 4 new test files (PublicationMode, ClubMemberships,
AuthorizedMembershipService, ClubShowcaseSource) + updates
to PublicClubPages, AuthorizedSessionService/Portfolio
service FakeSessionStore, CampaignTemplatesNavigation.
493 tests pass.

Bump version 3.6.0 -> 3.7.0 across Directory.Build.props,
compose.yaml, deploy.yml, NavMenu.razor.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/GmRelay.Bot.Tests/Web/PublicClubPagesTests.cs

@@ -14,6 +14,20 @@ public sealed class PublicClubPagesTests
         Assert.Contains("ix_sessions_public_schedule", migration, StringComparison.Ordinal);
     }
 
+    [Fact]
+    public async Task MigrationV030_ShouldAddClubMembershipsAndPublicationMode()
+    {
+        var migration = await ReadRepositoryFileAsync("src/GmRelay.Bot/Migrations/V030__add_club_memberships_and_publication_mode.sql");
+
+        Assert.Contains("CREATE TABLE club_memberships", migration, StringComparison.Ordinal);
+        Assert.Contains("status", migration, StringComparison.Ordinal);
+        Assert.Contains("role", migration, StringComparison.Ordinal);
+        Assert.Contains("ux_club_memberships_one_active", migration, StringComparison.Ordinal);
+        Assert.Contains("publication_mode", migration, StringComparison.Ordinal);
+        Assert.Contains("DROP COLUMN is_public", migration, StringComparison.Ordinal);
+        Assert.Contains("portfolio_games", migration, StringComparison.Ordinal);
+    }
+
     [Fact]
     public async Task PublicPages_ShouldExposeReadOnlyRoutesWithoutPrivateSessionData()
     {
@@ -40,10 +54,10 @@ public sealed class PublicClubPagesTests
 
         Assert.Contains("GetPublicClubBySlugAsync", sessionStore, StringComparison.Ordinal);
         Assert.Contains("GetPublicSessionAsync", sessionStore, StringComparison.Ordinal);
-        Assert.Contains("SetSessionPublicAsync", sessionStore, StringComparison.Ordinal);
-        Assert.Contains("SetBatchPublicAsync", sessionStore, StringComparison.Ordinal);
+        Assert.Contains("SetSessionPublicationModeAsync", sessionStore, StringComparison.Ordinal);
+        Assert.Contains("SetBatchPublicationModeAsync", sessionStore, StringComparison.Ordinal);
         Assert.Contains("g.public_schedule_enabled = true", service, StringComparison.Ordinal);
-        Assert.Contains("s.is_public = true", service, StringComparison.Ordinal);
+        Assert.Contains("s.publication_mode IN ('Catalog', 'Both')", service, StringComparison.Ordinal);
         Assert.Contains("s.status <> @Cancelled", service, StringComparison.Ordinal);
         Assert.DoesNotContain("p.display_name AS DisplayName,\r\n                   p.external_username", PublicQuerySection(service), StringComparison.Ordinal);
     }
@@ -55,8 +69,8 @@ public sealed class PublicClubPagesTests
         var authorizedService = await ReadRepositoryFileAsync("src/GmRelay.Web/Services/AuthorizedSessionService.cs");
 
         Assert.Contains("UpdatePublicGroupSettingsForCurrentUserAsync", groupDetailsPage, StringComparison.Ordinal);
-        Assert.Contains("SetSessionPublicForCurrentUserAsync", groupDetailsPage, StringComparison.Ordinal);
-        Assert.Contains("SetBatchPublicForCurrentUserAsync", groupDetailsPage, StringComparison.Ordinal);
+        Assert.Contains("SetSessionPublicationModeForCurrentUserAsync", groupDetailsPage, StringComparison.Ordinal);
+        Assert.Contains("SetBatchPublicationModeForCurrentUserAsync", groupDetailsPage, StringComparison.Ordinal);
         Assert.Contains("PublicSessionUrl", groupDetailsPage, StringComparison.Ordinal);
         Assert.Contains("NormalizePublicSlug", authorizedService, StringComparison.Ordinal);
         Assert.Contains("IsGroupManagerAsync", authorizedService, StringComparison.Ordinal);