feat(categories): implement professional category management experience

Categories dashboard (real total/visible/hidden/empty/root/subcategory/missing-image/missing-SEO/last-modified/completion% stats, recommended next action); tree view is now a real expand/collapse hierarchy (state persisted via LocalStorageService) with keyboard navigation (arrow keys, jump-to-parent), search that force-expands and keeps only matching branches + their ancestors/descendants instead of silently dropping deep matches; added Table/Cards views alongside the tree with density and saved column visibility; real bulk actions (show/hide/delete/assign parent/assign image via the Media Library picker/duplicate via the existing createCategory call/CSV export) plus the pre-existing single-item actions; reusable CategoryHealthWidget (image/SEO/description/valid-parent/visibility/products-assigned + completion%); editor reorganized into General/Media/SEO/Visibility/Navigation/Attributes/Advanced tabs, media now uses the shared ImageFieldComponent, SEO explains fields in plain language with a live preview, Navigation tab shows real breadcrumb/children/visibility-based nav status, Attributes uses the shared KeyValueEditorComponent. Filled in the adminCategories i18n namespace (previously only 2 of ~90 referenced keys existed) across en/ru/hy. Also fixed the pre-existing bug where a filtered/searched category list could silently drop a matched descendant whose ancestor's title didn't match, by loading the full catalog once and filtering client-side.

src/app/i18n/translations.ts

@@ -1228,6 +1228,84 @@ export interface Translations {
   adminCategories: {
     chooseImage: string;
     replaceImage: string;
+    search: string;
+    showDeleted: string;
+    create: string;
+    edit: string;
+    title: string;
+    slug: string;
+    slugTaken: string;
+    parent: string;
+    noParent: string;
+    icon: string;
+    image: string;
+    imageHint: string;
+    description: string;
+    items: string;
+    status: { draft: string; published: string };
+    restore: string;
+    saveDraft: string;
+    publish: string;
+    confirmDelete: string;
+    confirmLeaveUnsaved: string;
+    deleteBlocked: string;
+    emptyTitle: string;
+    emptyDescription: string;
+    emptyGuide: string;
+    viewTree: string;
+    viewCards: string;
+    expandAll: string;
+    collapseAll: string;
+    expandNode: string;
+    collapseNode: string;
+    jumpToParent: string;
+    deletedBadge: string;
+    column_slug: string;
+    column_items: string;
+    column_status: string;
+    column_visibility: string;
+    column_updated: string;
+    bulkAssignParent: string;
+    bulkAssignImage: string;
+    groupGeneral: string;
+    groupMedia: string;
+    groupSeo: string;
+    groupVisibility: string;
+    groupNavigation: string;
+    groupAttributes: string;
+    groupAdvanced: string;
+    visibilityExplain: string;
+    navBreadcrumb: string;
+    navRoot: string;
+    navChildren: string;
+    navNoChildren: string;
+    navAppearsIn: string;
+    navAppearsVisible: string;
+    navAppearsHidden: string;
+    itemsCountLabel: string;
+    createdAtLabel: string;
+    healthImage: string;
+    healthSeo: string;
+    healthDescription: string;
+    healthParent: string;
+    healthVisibility: string;
+    healthProducts: string;
+    totalCategories: string;
+    visibleCount: string;
+    hiddenCount: string;
+    emptyCount: string;
+    rootCount: string;
+    subCount: string;
+    missingImagesCount: string;
+    missingSeoCount: string;
+    lastModified: string;
+    lastModifiedNever: string;
+    completionLabel: string;
+    recommendedNext: string;
+    recommendAddImage: string;
+    recommendAddSeo: string;
+    recommendFillEmpty: string;
+    recommendNone: string;
   };
   adminProducts: {
     emptyTitle: string;