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-health.component.scss

@@ -0,0 +1,51 @@
+.dashboard-health__title {
+  margin: 0 0 12px;
+  font-size: 16px;
+  font-weight: 700;
+  color: var(--text-primary, #1e3c38);
+}
+
+.dashboard-health__all-clear {
+  margin: 0 0 8px;
+  font-size: 14px;
+  color: var(--success-color, #10b981);
+  font-weight: 600;
+}
+
+.dashboard-health__list {
+  list-style: none;
+  margin: 0;
+  padding: 0;
+  display: grid;
+  grid-template-columns: repeat(2, 1fr);
+  gap: 8px 16px;
+}
+
+.dashboard-health__item {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  font-size: 14px;
+  color: var(--text-primary, #1e3c38);
+}
+
+.dashboard-health__item--warning {
+  color: var(--warning-color, #f59e0b);
+  font-weight: 600;
+}
+
+.dashboard-health__dot {
+  width: 8px;
+  height: 8px;
+  border-radius: 50%;
+  background: var(--success-color, #10b981);
+  flex: none;
+}
+
+.dashboard-health__dot--warning {
+  background: var(--warning-color, #f59e0b);
+}
+
+@media (max-width: 640px) {
+  .dashboard-health__list { grid-template-columns: 1fr; }
+}