refactor: reorganize component files and update import paths; add PsItem and PsProduct interfaces

client/src/app/interfaces/product-list-item.ts

@@ -0,0 +1,7 @@
+export interface ProductListItem {
+  id: number;
+  name: string;
+  id_manufacturer?: number;
+  id_supplier?: number;
+  id_category_default?: number;
+}

client/src/app/interfaces/ps-item.ts

@@ -0,0 +1,5 @@
+export interface PsItem {
+  id: number;
+  name: string;
+  active?: boolean;
+}

client/src/app/interfaces/ps-product.ts

@@ -0,0 +1,15 @@
+export interface PsProduct {
+  name: string;
+  description?: string;    // texte saisi libre
+  categoryId: number;      // id_category_default + associations
+  manufacturerId: number;
+  supplierId: number;
+  images?: File[];         // optionnel
+  // Champs “hors Presta” injectés dans la description :
+  conditionLabel?: string; // ex. "Occasion"
+  complete?: boolean;      // Complet
+  hasManual?: boolean;     // Notice
+  priceTtc: number;          // saisi côté UI (TTC)
+  vatRate?: number;          // ex: 0.20 (20%). Défaut: 0.20 si non fourni
+  quantity: number;         // stock souhaité (pour id_product_attribute = 0)
+}