fix(admin): polish marketplace-builder

Remove unused ButtonComponent import/registration from
ProjectEditorHomepageSectionComponent — it was never referenced in the
template and had been flagged by every build (NG8113 warning).

Reviewed sections/pages/components: save-bar, brand-overview,
footer-section, homepage-overview, widgets-section, project-editor-nav,
builder-overview-page. All buttons already route through the shared
app-button (which carries its own :focus-visible); no orphaned
bindings or corrupted glyphs found (scanned same way as the storefront
pass). No further changes needed.

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

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

@@ -5,7 +5,6 @@ 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 { HomepageOverviewComponent } from './homepage/homepage-overview.component';
@@ -42,7 +41,7 @@ const BLOCK_BY_TYPE = new Map(BLOCK_CATALOG.map(entry => [entry.type, entry]));
 @Component({
   selector: 'app-project-editor-homepage-section',
   standalone: true,
-  imports: [DragDropModule, FormsModule, TranslatePipe, InputComponent, ButtonComponent, SectionCardComponent, ToggleComponent, HomepageOverviewComponent],
+  imports: [DragDropModule, FormsModule, TranslatePipe, InputComponent, SectionCardComponent, ToggleComponent, HomepageOverviewComponent],
   templateUrl: './homepage-section.component.html',
   styleUrls: ['./section.shared.scss', './homepage-section.component.scss'],
   changeDetection: ChangeDetectionStrategy.OnPush