feat: add support for individual consumable items in service items

- Introduced `consumables` field in `ServiceItem` to allow multiple individual items alongside inventory packages.
- Created `ServiceItemConsumable` entity to manage individual consumable items linked to a service.
- Updated `ServiceItemController` to handle CRUD operations for consumables.
- Enhanced `ServiceDetailPage` and `ServiceItemFormModal` to display and manage consumables.
- Added tests to ensure functionality for adding, updating, and validating consumables.
- Updated API documentation to reflect changes in service item structure and consumables.

assets/admin/types/index.ts

@@ -510,6 +510,16 @@ export interface ServiceSection {
     items_count?: number;
 }
 
+/** یک قلم کالای تکی روی سرویس (خروجی ServiceItemConsumable::toArray) */
+export interface ServiceConsumable {
+    item_uuid: string;
+    name: string;
+    unit: string;
+    price: number;   // Rial
+    stock: number;
+    amount: number;
+}
+
 export interface ServiceItem {
     uuid: string;
     name: string;
@@ -519,6 +529,8 @@ export interface ServiceItem {
     /** پکیج کالای مصرفی متصل به این خدمت (اختیاری) */
     inventory_package_uuid?: string | null;
     inventory_package_title?: string | null;
+    /** اقلام کالای تکی — مستقل از پکیج و قابل استفاده هم‌زمان با آن */
+    consumables?: ServiceConsumable[];
     created_at?: number;
     updated_at?: number;
     /** primary staff (first member) — kept for backward compatibility */