feat(admin): visual badge manager with storefront-accurate previews

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

P0 user feedback: badges were a comma-separated text input with no preview.

- Replaced with a chip editor: current badges render as removable pills in the exact colors customers see on the storefront (colors sourced from getBadgeClass/item.utils.ts so admin preview and product card never drift)
- The standard set (new/sale/exclusive/hot/limited/bestseller/featured) is offered as one-click add chips; custom badges added via text field, unlimited, shown in the storefront's custom-badge grey
- Deliberately NOT per-badge arbitrary colors: badge colors are part of the storefront design contract (string[] + fixed palette); introducing per-badge color storage would change the product data shape consumed by the future backend
- New adminProducts keys (badgesHint, addBadge, removeBadge, customBadgePlaceholder) in en/ru/hy; verified in browser

src/app/i18n/translations.ts

@@ -1553,6 +1553,10 @@ export interface Translations {
     seoGenerate: string;
     seoGenerateHint: string;
     translationsHint: string;
+    badgesHint: string;
+    addBadge: string;
+    removeBadge: string;
+    customBadgePlaceholder: string;
     seoExplain: string;
     searchTitle: string;
     searchTitleHint: string;