feat(project-editor): finish field descriptions + enum dropdowns across all sections

Wires up the remaining editor sections (theme, header, footer, homepage,
widgets, features, languages, navigation) with the description text and
dropdown UX started for General/Branding:

- Every enum-backed field is now a <select> with a description per option,
  not free text: theme.mode, the new site-wide layout.type (previously had
  no editor at all - added to the Theme section, and added to that
  section's reset-scope), homepage section layout.strategy, and
  catalog.navigationMode (also previously unedited, added to Features).
- Every other field (colors, header toggles, footer contact/company fields,
  widget props, feature flags, language add, nav link label/url/visible)
  gets a one-line plain-language description under its label via the new
  *Desc i18n keys (en/ru/hy) prepared earlier.
- Genuinely open text (widget layout variant strings, JSON props) stays
  free text, description-only, per the existing widgetLayoutDesc/widgetJsonDesc
  wording - not force-fit into a dropdown.

Verified: tsc --noEmit and ng build both clean.

src/app/features/project-editor/sections/features-section.component.ts

@@ -1,11 +1,18 @@
 import { ChangeDetectionStrategy, Component, inject } from '@angular/core';
+import { FormsModule } from '@angular/forms';
 import { ProjectEditorFacade } from '../facade/project-editor.facade';
 import { TranslatePipe } from '../../../i18n/translate.pipe';
 
+export interface CatalogNavigationOption {
+  value: 'default' | 'left-category-navigation' | 'mega-category-layout' | 'top-category-carousel';
+  labelKey: string;
+  descKey: string;
+}
+
 @Component({
   selector: 'app-project-editor-features-section',
   standalone: true,
-  imports: [TranslatePipe],
+  imports: [FormsModule, TranslatePipe],
   templateUrl: './features-section.component.html',
   styleUrls: ['./section.shared.scss'],
   changeDetection: ChangeDetectionStrategy.OnPush
@@ -14,6 +21,24 @@ export class ProjectEditorFeaturesSectionComponent {
   private readonly facade = inject(ProjectEditorFacade);
   readonly bootstrap = this.facade.bootstrap;
 
+  readonly catalogNavigationOptions: CatalogNavigationOption[] = [
+    { value: 'default', labelKey: 'builder.catalogNavDefault', descKey: 'builder.catalogNavDefaultDesc' },
+    { value: 'left-category-navigation', labelKey: 'builder.catalogNavLeftCategory', descKey: 'builder.catalogNavLeftCategoryDesc' },
+    { value: 'mega-category-layout', labelKey: 'builder.catalogNavMegaCategory', descKey: 'builder.catalogNavMegaCategoryDesc' },
+    { value: 'top-category-carousel', labelKey: 'builder.catalogNavTopCarousel', descKey: 'builder.catalogNavTopCarouselDesc' },
+  ];
+
+  catalogNavigationDescKey(mode: string | undefined): string {
+    return this.catalogNavigationOptions.find(option => option.value === mode)?.descKey ?? '';
+  }
+
+  updateCatalogNavigationMode(mode: string): void {
+    this.facade.updateBootstrap(current => ({
+      ...current,
+      catalog: { ...current.catalog, navigationMode: mode as CatalogNavigationOption['value'] }
+    }));
+  }
+
   toggleFeature(key: string, checked: boolean): void {
     this.facade.updateBootstrap(current => ({ ...current, featureFlags: { ...current.featureFlags, [key]: checked } }));
   }