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/components/admin-dashboard-quick-actions.component.scss

@@ -0,0 +1,43 @@
+.dashboard-quick-actions__title {
+  margin: 0 0 12px;
+  font-size: 16px;
+  font-weight: 700;
+  color: var(--text-primary, #1e3c38);
+}
+
+.dashboard-quick-actions__grid {
+  display: grid;
+  grid-template-columns: repeat(4, 1fr);
+  gap: 12px;
+}
+
+.dashboard-quick-actions__item {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  text-align: center;
+  min-height: 56px;
+  padding: 10px 12px;
+  border: 1px solid var(--border-color, #d3dad9);
+  border-radius: var(--radius-md, 12px);
+  background: var(--bg-primary, #fff);
+  color: var(--text-primary, #1e3c38);
+  font-weight: 600;
+  font-size: 14px;
+  text-decoration: none;
+  transition: border-color 0.15s ease, box-shadow 0.15s ease;
+}
+
+.dashboard-quick-actions__item:hover,
+.dashboard-quick-actions__item:focus-visible {
+  border-color: var(--primary-color, #497671);
+  box-shadow: var(--shadow-sm, 0 2px 8px rgba(0, 0, 0, 0.1));
+}
+
+@media (max-width: 960px) {
+  .dashboard-quick-actions__grid { grid-template-columns: repeat(2, 1fr); }
+}
+
+@media (max-width: 560px) {
+  .dashboard-quick-actions__grid { grid-template-columns: 1fr; }
+}