feat(inventory): add origin field to InventoryItem and update related DTOs and services

backend/src/inventory/dto/create-inventory.dto.ts

@@ -32,6 +32,10 @@ export class CreateInventoryDto {
   @IsString()
   brand?: string;
 
+  @IsOptional()
+  @IsString()
+  origin?: string;
+
   @IsOptional()
   @IsString()
   receiptName?: string;

backend/src/inventory/inventory.service.ts

@@ -143,6 +143,7 @@ export class InventoryService {
       quantity: new Prisma.Decimal(data.quantity),
       location: data.location?.trim() || undefined,
       brand: data.brand?.trim() || undefined,
+      origin: data.origin?.trim() || undefined,
       receiptName: data.receiptName?.trim() || undefined,
       suitableFor: data.suitableFor?.trim() || undefined,
       comment: data.comment?.trim() || undefined,