feat: Phase 7 frontend - Refund/Reconciliation core + Payments & Finance section

New core/finance (Refund/ReconciliationRecord/Settlement models + gateway/
token, mock backed, seeded empty) and features/admin/finance (facade +
page: reconciliation queue with resolve action, settlements placeholder).
New /backoffice/finance route + nav entry, nav i18n key in all 3 languages.
Against docs/backend/PHASE-7-PAYMENTS-RECONCILIATION-CONTRACT.md.

Note: does not wire AdminOrdersLocalGateway's existing mock
requestRefund(id) method into this new Refund flow yet - that's a small
follow-up once Phase 2's real Order backend exists to refund against.

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

src/app/app.routes.ts

@@ -209,6 +209,15 @@ const coreRoutes: Routes = [
           breadcrumb: [{ labelKey: 'adminShell.nav.integrations' }]
         }
       },
+      {
+        path: 'finance',
+        loadComponent: () => import('./features/admin/finance/pages/admin-finance-page.component').then(m => m.AdminFinancePageComponent),
+        data: {
+          titleKey: 'adminShell.nav.finance',
+          descriptionKey: 'adminShell.nav.finance',
+          breadcrumb: [{ labelKey: 'adminShell.nav.finance' }]
+        }
+      },
       {
         path: 'moderation',
         loadComponent: () => import('./features/admin/moderation/pages/admin-reviews-list-page.component').then(m => m.AdminReviewsListPageComponent),