feat(product): add reusable Product Experience 2.0

Unify product details modules behind config-driven contracts so teams can
extend UX without changing runtime architecture or bootstrap flow.

Keep backward compatibility with existing product payloads by treating new
media/specification/variant/related structures as optional extensions.

Improve conversion and content discoverability with reusable actions,
typed media rendering, grouped specifications, dynamic variants, and
multi-collection related products.

src/app/models/item.model.ts

@@ -5,6 +5,18 @@ interface Photo {
   type?: string;
 }
 
+export type ProductMediaType = 'image' | 'video' | 'pdf' | 'manual' | 'warranty';
+
+export interface ProductMedia {
+  id?: string;
+  type: ProductMediaType;
+  url: string;
+  thumbnailUrl?: string;
+  alt?: string;
+  title?: string;
+  labels?: Record<string, string>;
+}
+
 export interface DescriptionField {
   key: string;
   value: string;
@@ -59,6 +71,47 @@ interface ItemAttribute {
   value: string;
 }
 
+interface LocalizedValue {
+  [language: string]: string;
+}
+
+export interface ProductSpecificationField {
+  key: string;
+  value: string;
+  label?: string;
+  labels?: LocalizedValue;
+  unit?: string;
+}
+
+export interface ProductSpecificationGroup {
+  id?: string;
+  key: string;
+  label?: string;
+  labels?: LocalizedValue;
+  attributes: ProductSpecificationField[];
+}
+
+export interface ProductVariantOption {
+  value: string;
+  label?: string;
+  labels?: LocalizedValue;
+  available?: boolean;
+}
+
+export interface ProductVariantOptionGroup {
+  key: string;
+  label?: string;
+  labels?: LocalizedValue;
+  options: ProductVariantOption[];
+}
+
+export interface RelatedProductCollection {
+  id: string;
+  title: string;
+  titles?: LocalizedValue;
+  products: number[];
+}
+
 export interface DeliveryOption {
   deliveryPrice: number;
   deliveryPlace: string;
@@ -104,6 +157,10 @@ export interface Item {
   names?: ItemName[];
   descriptions?: ItemDescription[];
   attributes?: ItemAttribute[];
+  media?: ProductMedia[];
+  specificationGroups?: ProductSpecificationGroup[];
+  variantOptions?: ProductVariantOptionGroup[];
+  relatedCollections?: RelatedProductCollection[];
 
   // BackOffice API fields
   id?: string;