feat: group thousands in inventory item price input

Show the قیمت (تومان) field with thousand separators as the user types
(e.g. 1200000 → 1,200,000). Stored value stays digit-only, so the
Toman→Rial conversion on submit is unaffected.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

assets/admin/components/inventory/AddItemModal.tsx

@@ -23,6 +23,8 @@ interface FormState {
 const BLANK: FormState = { name: '', consumable: '', unit: '', price: '', stock: '', alertThreshold: '' };
 
 const digits = (v: string) => toEnglishDigits(v).replace(/\D/g, '');
+// group thousands: "1200000" → "1,200,000"
+const group = (v: string) => v.replace(/\B(?=(\d{3})+(?!\d))/g, ',');
 
 /** «افزودن/ویرایش کالای جدید» — mirrors tauri ModalAddInventory field-for-field. */
 export default function AddItemModal({ open, editing, saving, onClose, onSave }: Props) {
@@ -79,7 +81,7 @@ export default function AddItemModal({ open, editing, saving, onClose, onSave }:
             <label className="field-label">{f.label}</label>
             <div className="field">
               <input
-                value={form[f.key]}
+                value={f.key === 'price' ? group(form.price) : form[f.key]}
                 onChange={f.numeric ? setNum(f.key) : set(f.key)}
                 placeholder={f.placeholder}
                 inputMode={f.numeric ? 'numeric' : undefined}

assets/admin/pages/InventoryPage.test.tsx

@@ -62,6 +62,11 @@ describe('InventoryPage', () => {
     expect(await screen.findByText('افزودن کالای جدید')).toBeInTheDocument();
     // the source's distinctive "هشدار اتمام" field is present
     expect(screen.getByText('هشدار اتمام')).toBeInTheDocument();
+
+    // price input groups thousands as the user types
+    const price = screen.getByPlaceholderText('قیمت') as HTMLInputElement;
+    fireEvent.change(price, { target: { value: '1200000' } });
+    expect(price.value).toBe('1,200,000');
   });
 
   it('switches to the packages tab and lists a package with its price', async () => {