feat(project-editor): reusable image-field (thumbnail+replace+remove), branding OG image+gallery

- shared app-image-field component: thumbnail preview, replace, remove, opens media-picker
- branding: add socialImageUrl + galleryUrls fields, wire to new image-field
- footer: logo + payment icon fields use image-field (drop manual media-picker plumbing)
- i18n: common.remove, adminCategories.replaceImage, builder.socialImage/gallery keys (en/ru/hy)

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

src/app/shared/ui/image-field/image-field.component.ts

@@ -0,0 +1,41 @@
+import { ChangeDetectionStrategy, Component, input, output } from '@angular/core';
+import { FormsModule } from '@angular/forms';
+import { TranslatePipe } from '../../../i18n/translate.pipe';
+import { MediaAsset } from '../../../core/media/models/media-asset.model';
+import { InputComponent } from '../input/input.component';
+import { ButtonComponent } from '../button/button.component';
+import { MediaPickerComponent } from '../../media/media-picker/media-picker.component';
+
+@Component({
+  selector: 'app-image-field',
+  standalone: true,
+  imports: [FormsModule, TranslatePipe, InputComponent, ButtonComponent, MediaPickerComponent],
+  templateUrl: './image-field.component.html',
+  styleUrl: './image-field.component.scss',
+  changeDetection: ChangeDetectionStrategy.OnPush
+})
+export class ImageFieldComponent {
+  readonly value = input<string | null | undefined>('');
+  readonly disabled = input(false);
+
+  readonly valueChange = output<string>();
+
+  protected pickerOpen = false;
+
+  protected setValue(next: string): void {
+    this.valueChange.emit(next);
+  }
+
+  protected openPicker(): void {
+    this.pickerOpen = true;
+  }
+
+  protected onPicked(asset: MediaAsset): void {
+    this.valueChange.emit(asset.url);
+    this.pickerOpen = false;
+  }
+
+  protected remove(): void {
+    this.valueChange.emit('');
+  }
+}