feat(admin): sprint 19 admin dashboard, routing, i18n

- Add admin dashboard feature (models/gateway/facade/components/page)
- Wire admin/products routes and backoffice coming-soon placeholders
- Add lastPublishedAt to ProjectEditorFacade/state
- Add dashboard i18n keys (en/ru/hy) and docs/ADMIN.md

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

src/app/features/admin/dashboard/facade/admin-dashboard.facade.ts

@@ -0,0 +1,125 @@
+import { Injectable, computed, effect, inject, signal } from '@angular/core';
+import { take } from 'rxjs/operators';
+import { ProjectEditorFacade } from '../../../project-editor/facade/project-editor.facade';
+import { ADMIN_DASHBOARD_METRICS_GATEWAY } from '../services/admin-dashboard-metrics-gateway.token';
+import { AdminDashboardHistoryService } from '../services/admin-dashboard-history.service';
+import {
+  AdminDashboardCardState,
+  AdminDashboardHealthCheck,
+  AdminDashboardMetrics,
+  AdminDashboardQuickAction,
+} from '../models/admin-dashboard.model';
+
+const QUICK_ACTIONS: AdminDashboardQuickAction[] = [
+  { id: 'edit-project', labelKey: 'dashboard.actionEditProject', route: ['edit', 'general'] },
+  { id: 'categories', labelKey: 'dashboard.actionCategories', route: ['backoffice', 'categories'] },
+  { id: 'products', labelKey: 'dashboard.actionProducts', route: ['backoffice', 'products'] },
+  { id: 'static-pages', labelKey: 'dashboard.actionStaticPages', route: ['backoffice', 'static-pages'] },
+  { id: 'transactions', labelKey: 'dashboard.actionTransactions', route: ['backoffice', 'transactions'] },
+  { id: 'orders', labelKey: 'dashboard.actionOrders', route: ['backoffice', 'orders'] },
+  { id: 'media-library', labelKey: 'dashboard.actionMediaLibrary', route: ['backoffice', 'media'] },
+  { id: 'preview-marketplace', labelKey: 'dashboard.actionPreviewMarketplace', route: [''] },
+];
+
+/**
+ * Composes ProjectEditorFacade (bootstrap/status/save-publish timestamps/validation)
+ * with dashboard-only metrics/history so the page component stays presentational.
+ * Cards read through here, never directly from ConfigService or localStorage -
+ * swapping local sources for real backend endpoints only touches this facade
+ * and the gateways it calls, per ADR-006/007.
+ */
+@Injectable({ providedIn: 'root' })
+export class AdminDashboardFacade {
+  private readonly projectEditor = inject(ProjectEditorFacade);
+  private readonly metricsGateway = inject(ADMIN_DASHBOARD_METRICS_GATEWAY);
+  private readonly history = inject(AdminDashboardHistoryService);
+
+  private readonly metricsState = signal<AdminDashboardCardState<AdminDashboardMetrics>>({ status: 'loading', value: null });
+  private readonly activityTick = signal(0);
+
+  readonly bootstrap = this.projectEditor.bootstrap;
+  readonly status = this.projectEditor.status;
+  readonly lastSavedAt = this.projectEditor.lastSavedAt;
+  readonly lastPublishedAt = this.projectEditor.lastPublishedAt;
+  readonly validationIssues = this.projectEditor.validationIssues;
+  readonly homepageWidgets = this.projectEditor.homepageWidgets;
+  readonly metrics = this.metricsState.asReadonly();
+
+  readonly quickActions: AdminDashboardQuickAction[] = QUICK_ACTIONS;
+
+  readonly enabledWidgetsCount = computed(() => this.homepageWidgets().length);
+
+  readonly activityEntries = computed(() => {
+    this.activityTick();
+    const tenantId = this.bootstrap()?.tenant.id;
+    return tenantId ? this.history.list(tenantId) : [];
+  });
+
+  readonly healthChecks = computed<AdminDashboardHealthCheck[]>(() => {
+    const current = this.bootstrap();
+    const issues = new Set(this.validationIssues().map(issue => issue.code));
+    return [
+      { code: 'bootstrap-valid', labelKey: 'dashboard.healthBootstrapValid', healthy: !!current?.schemaVersion },
+      { code: 'configuration-valid', labelKey: 'dashboard.healthConfigurationValid', healthy: issues.size === 0 },
+      { code: 'missing-translations', labelKey: 'dashboard.healthMissingTranslations', healthy: !issues.has('missing-translations') },
+      { code: 'invalid-colors', labelKey: 'dashboard.healthInvalidColors', healthy: !issues.has('invalid-colors') },
+      { code: 'invalid-widget-references', labelKey: 'dashboard.healthInvalidWidgetReferences', healthy: !issues.has('missing-widget') },
+      { code: 'invalid-layouts', labelKey: 'dashboard.healthInvalidLayouts', healthy: !issues.has('invalid-layouts') },
+    ];
+  });
+
+  private lastRecordedSavedAt: number | null = null;
+  private lastRecordedPublishedAt: number | null = null;
+  private historyPrimed = false;
+
+  constructor() {
+    effect(() => {
+      const tenantId = this.bootstrap()?.tenant.id;
+      const savedAt = this.lastSavedAt();
+      const publishedAt = this.lastPublishedAt();
+      if (!tenantId) {
+        return;
+      }
+
+      if (!this.historyPrimed) {
+        this.historyPrimed = true;
+        this.lastRecordedSavedAt = savedAt;
+        this.lastRecordedPublishedAt = publishedAt;
+        return;
+      }
+
+      let recorded = false;
+      if (savedAt !== null && savedAt !== this.lastRecordedSavedAt) {
+        this.lastRecordedSavedAt = savedAt;
+        this.history.record(tenantId, 'draft-saved', savedAt);
+        recorded = true;
+      }
+      if (publishedAt !== null && publishedAt !== this.lastRecordedPublishedAt) {
+        this.lastRecordedPublishedAt = publishedAt;
+        this.history.record(tenantId, 'published', publishedAt);
+        recorded = true;
+      }
+      if (recorded) {
+        this.activityTick.update(tick => tick + 1);
+      }
+    });
+  }
+
+  ensureLoaded(): void {
+    if (!this.bootstrap()) {
+      this.projectEditor.loadBootstrap();
+    }
+    this.loadMetrics();
+  }
+
+  loadMetrics(): void {
+    this.metricsState.set({ status: 'loading', value: null });
+    this.metricsGateway.loadMetrics().pipe(take(1)).subscribe({
+      next: metrics => this.metricsState.set({
+        status: metrics.categoriesCount === 0 && metrics.productsCount === 0 ? 'empty' : 'ready',
+        value: metrics,
+      }),
+      error: () => this.metricsState.set({ status: 'error', value: null }),
+    });
+  }
+}