fix(storefront): release-candidate walkthrough fixes

- Cart item description showed a stray literal "..." when the item had no
  description text (cart.component.html) — now only renders the trailing
  ellipsis when a description is present.
- Compare table showed raw internal stock enum values ("high"/"low"/etc.)
  instead of localized labels (compare-table.component.ts) — now reuses the
  same stock-label mapping used by product cards.
- Search with zero results incorrectly showed the empty-category messaging
  ("browse categories" / "go to parent category") stacked on top of the
  search's own "nothing found" message (catalog-container.component.ts) —
  isEmptyCategoryState now excludes active search queries so only the
  search-appropriate empty state renders.
- Footer "About" link pointed to /about, which 404s; the actual CMS page
  route is /about-us (bootstrap.json mock nav data) — corrected the route.
- Added missing public/assets/images/placeholder.svg, the fallback image
  referenced by getMainImage() for items without photos (previously 404s
  if that fallback path is ever hit).

Investigated and left as-is (not code bugs): /images/*.webp 404s on
product cards are references to a real backend/CDN not present in local
dev (confirmed via mock-data.interceptor.ts and api.service.ts image-URL
resolution) — expected dev-only gap. Footer "Contacts" link (/contacts)
has no corresponding static page content at all in mock data; flagging
for a content decision rather than fabricating copy.

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

src/app/features/website/user-experience/compare/components/compare-table.component.ts

@@ -10,6 +10,13 @@ interface CompareRow {
   identical: boolean;
 }
 
+const STOCK_LABEL_KEYS: Record<string, string> = {
+  high: 'catalog.stockHigh',
+  medium: 'catalog.stockMedium',
+  low: 'catalog.stockLow',
+  out: 'catalog.stockOut'
+};
+
 @Component({
   selector: 'app-compare-table',
   standalone: true,
@@ -34,7 +41,7 @@ export class CompareTableComponent {
     const baseRows: CompareRow[] = [
       this.toRow('price', this.i18n.t('ux.comparePrice'), products.map(product => `${product.price.toFixed(2)} ${product.currency}`)),
       this.toRow('rating', this.i18n.t('ux.compareRating'), products.map(product => `${(product.rating ?? 0).toFixed(1)}`)),
-      this.toRow('stock', this.i18n.t('ux.compareStock'), products.map(product => product.remainings ?? this.i18n.t('ux.compareUnknown'))),
+      this.toRow('stock', this.i18n.t('ux.compareStock'), products.map(product => this.stockLabel(product.remainings))),
       this.toRow('discount', this.i18n.t('ux.compareDiscount'), products.map(product => `${product.discount ?? 0}%`)),
       this.toRow('color', this.i18n.t('ux.compareColor'), products.map(product => product.colour ?? '—')),
       this.toRow('size', this.i18n.t('ux.compareSize'), products.map(product => product.size ?? '—'))
@@ -58,6 +65,14 @@ export class CompareTableComponent {
     return this.highlightDifferences && !row.identical;
   }
 
+  private stockLabel(remainings: string | undefined): string {
+    if (!remainings) {
+      return this.i18n.t('ux.compareUnknown');
+    }
+    const key = STOCK_LABEL_KEYS[remainings.toLowerCase()];
+    return key ? this.i18n.t(key) : remainings;
+  }
+
   private toRow(key: string, label: string, values: string[]): CompareRow {
     const normalized = values.map(value => value.trim().toLowerCase());
     const identical = normalized.every(value => value === normalized[0]);