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/features/project-editor/sections/widgets-section.component.ts

@@ -4,10 +4,16 @@ import { ProjectEditorFacade } from '../facade/project-editor.facade';
 import { TranslatePipe } from '../../../i18n/translate.pipe';
 import { TranslateService } from '../../../i18n/translate.service';
 import { InputComponent } from '../../../shared/ui/input/input.component';
+import { ButtonComponent } from '../../../shared/ui/button/button.component';
 import { SectionCardComponent } from '../../../shared/ui/section-card/section-card.component';
 import { ToggleComponent } from '../../../shared/ui/toggle/toggle.component';
 import { WidgetConfig } from '../../../shared/models/config';
 
+interface HeroSlideDraft {
+  title: string;
+  subtitle: string;
+}
+
 const WIDGET_ICONS: Record<string, string> = {
   hero: 'pi-image',
   categories: 'pi-th-large',
@@ -23,7 +29,7 @@ const WIDGET_LABEL_KEYS: Record<string, string> = {
 @Component({
   selector: 'app-project-editor-widgets-section',
   standalone: true,
-  imports: [FormsModule, TranslatePipe, InputComponent, SectionCardComponent, ToggleComponent],
+  imports: [FormsModule, TranslatePipe, InputComponent, ButtonComponent, SectionCardComponent, ToggleComponent],
   templateUrl: './widgets-section.component.html',
   styleUrls: ['./section.shared.scss', './widgets-section.component.scss'],
   changeDetection: ChangeDetectionStrategy.OnPush
@@ -136,6 +142,44 @@ export class ProjectEditorWidgetsSectionComponent {
     this.updateWidget(widgetId, props => ({ ...props, [key]: value }));
   }
 
+  /** Extra slides beyond the widget's primary title/subtitle (which stay editable as "slide 1" via the existing fields above this list). */
+  heroSlides(widget: WidgetConfig): HeroSlideDraft[] {
+    const raw = widget.props?.['slides'];
+    if (!Array.isArray(raw)) {
+      return [];
+    }
+    return raw.map(slide => ({
+      title: typeof slide?.title === 'string' ? slide.title : '',
+      subtitle: typeof slide?.subtitle === 'string' ? slide.subtitle : '',
+    }));
+  }
+
+  addHeroSlide(widgetId: string): void {
+    this.updateWidget(widgetId, props => ({
+      ...props,
+      slides: [...this.slidesArray(props), { title: '', subtitle: '' }],
+    }));
+  }
+
+  updateHeroSlide(widgetId: string, index: number, field: 'title' | 'subtitle', value: string): void {
+    this.updateWidget(widgetId, props => ({
+      ...props,
+      slides: this.slidesArray(props).map((slide, i) => i === index ? { ...slide, [field]: value } : slide),
+    }));
+  }
+
+  removeHeroSlide(widgetId: string, index: number): void {
+    this.updateWidget(widgetId, props => ({
+      ...props,
+      slides: this.slidesArray(props).filter((_, i) => i !== index),
+    }));
+  }
+
+  private slidesArray(props: Record<string, unknown>): HeroSlideDraft[] {
+    const raw = props['slides'];
+    return Array.isArray(raw) ? raw : [];
+  }
+
   private readonly jsonDrafts = signal<Record<string, string>>({});
   private readonly jsonErrors = signal<Record<string, string>>({});