feat: Phase 9 frontend - Marketplaces registry + Domains & Releases (combined page)

core/marketplace-registry (Marketplace/MarketplaceDomain/
LifecycleAdvanceResult models + gateway/token) derives a single-row
registry from the current tenant's own live bootstrap config and current
hostname, since the platform runs one tenant per deployment today with no
registry anywhere. New features/admin/marketplaces page + nav entry.
Against docs/backend/PHASE-9-TENANT-REGISTRY-DOMAINS-CONTRACT.md.

Scope simplification: combined "Marketplaces" and "Domains & Releases"
(two separate backoffice sections in the plan) into one page with two
sections, to keep pace through this push - splitting them into dedicated
routes is a small follow-up once there's real multi-marketplace data to
justify two separate list views. Onboarding wizard (8 steps), Hostinger
DNS automation, and the full lifecycle-advance state machine are not
built - registry/domain/lifecycle read-only display only.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/app/app.routes.ts

@@ -218,6 +218,15 @@ const coreRoutes: Routes = [
           breadcrumb: [{ labelKey: 'adminShell.nav.finance' }]
         }
       },
+      {
+        path: 'marketplaces',
+        loadComponent: () => import('./features/admin/marketplaces/pages/admin-marketplaces-page.component').then(m => m.AdminMarketplacesPageComponent),
+        data: {
+          titleKey: 'adminShell.nav.marketplaces',
+          descriptionKey: 'adminShell.nav.marketplaces',
+          breadcrumb: [{ labelKey: 'adminShell.nav.marketplaces' }]
+        }
+      },
       {
         path: 'moderation',
         loadComponent: () => import('./features/admin/moderation/pages/admin-reviews-list-page.component').then(m => m.AdminReviewsListPageComponent),