feat(builder): visual homepage blocks, merchant-language widget settings, real carousel arrows

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

P0 user feedback: homepage builder showed raw section.id like 'section-hero'/'section-categories'; hero widget exposed 'full-bleed'/'boxed' and raw px/vh as free text with no explanation; Overlay/Autoplay toggles made no sense without a slides concept; product carousel widgets rendered arrows nowhere near a working carousel.

Homepage section (sections list -> visual blocks):
- Replaced raw section.id display with a merchant-facing block catalog (icon + name + one-line explanation) for hero/categories/featured-products/product-carousel/recently-viewed/banner/partners/custom-html
- Added block catalog picker to append new blocks (was fixed at whatever the seed data had - task asked 'what if we add manually? not fixed 3')
- Added duplicate and remove per block, alongside the existing drag-to-reorder
- Verified in browser: labels render correctly, add-block and duplicate both confirmed working end-to-end

Widgets section (hero widget):
- 'Layout' free-text replaced with a select (Full width / Boxed) instead of typing 'full-bleed'/'boxed' blind
- 'Height' free-text replaced with a select (Compact/Medium/Tall/Full screen) mapped to real vh values
- New Slides editor: title/subtitle pairs an admin can add/remove: this is the actual multi-slide data the Overlay/Autoplay toggles were referring to with nothing to point at before
- HeroWidgetData contract gains slides[]/autoplay; HeroWidgetComponent now renders a real rotator (dots, click-to-jump, autoplay interval) when more than one slide exists - previously autoplay/overlay props existed but there was no slideshow behavior anywhere to control

Carousel arrows root cause and fix:
- widget-manifest.json offers 'carousel' as a layout option for product-collection/product-carousel widgets, and the admin UI let you select it, but ProductCarouselWidgetComponent always rendered a static CSS grid regardless - there was no carousel implementation to have arrows in the first place
- Now renders a real horizontally-scrollable strip with working prev/next buttons (native scrollBy, disabled at each end) when section.layout.strategy === 'carousel'; falls back to the existing grid otherwise
- Confirmed src/app/components/items-carousel (a PrimeNG p-carousel) is dead code, not wired into any route or widget - not the source of the reported bug

New builder.* i18n keys (en/ru/hy), zero duplicate-key collisions verified via scan

src/app/widgets/resolvers/data-source-resolver.service.ts

@@ -85,12 +85,26 @@ export class DataSourceResolverService {
   }
 
   private toHeroData(section: SectionConfig, settings: Record<string, unknown>): HeroWidgetData {
+    const rawSlides = settings['slides'];
+    const slides = Array.isArray(rawSlides)
+      ? rawSlides
+          .filter((slide): slide is Record<string, unknown> => !!slide && typeof slide === 'object')
+          .map(slide => ({
+            title: String(slide['title'] ?? ''),
+            subtitle: slide['subtitle'] != null ? String(slide['subtitle']) : undefined,
+            ctaLabel: slide['ctaLabel'] != null ? String(slide['ctaLabel']) : undefined,
+          }))
+          .filter(slide => slide.title)
+      : undefined;
+
     return {
       section,
       settings,
       title: String(settings['title'] ?? ''),
       subtitle: settings['subtitle'] != null ? String(settings['subtitle']) : undefined,
-      ctaLabel: settings['ctaLabel'] != null ? String(settings['ctaLabel']) : undefined
+      ctaLabel: settings['ctaLabel'] != null ? String(settings['ctaLabel']) : undefined,
+      slides,
+      autoplay: settings['autoplay'] === true,
     };
   }