fix(manufacturing): make item_code mandatory in Job Card Item

The item_code field in the Job Card Item child table was optional,
allowing job cards to be saved without a raw material item linked.
Set reqd=1 in the JSON and update the Python type annotation accordingly.

(cherry picked from commit d7e9a97f8a)

erpnext/manufacturing/doctype/job_card_item/job_card_item.json

@@ -26,7 +26,8 @@
    "fieldtype": "Link",
    "in_list_view": 1,
    "label": "Item Code",
-   "options": "Item"
+   "options": "Item",
+   "reqd": 1
   },
   {
    "fieldname": "source_warehouse",
@@ -107,7 +108,7 @@
  "index_web_pages_for_search": 1,
  "istable": 1,
  "links": [],
- "modified": "2026-05-12 12:22:18.506904",
+ "modified": "2026-06-23 16:52:37.669110",
  "modified_by": "Administrator",
  "module": "Manufacturing",
  "name": "Job Card Item",

erpnext/manufacturing/doctype/job_card_item/job_card_item.py

@@ -16,7 +16,7 @@ class JobCardItem(Document):
 
 		allow_alternative_item: DF.Check
 		description: DF.Text | None
-		item_code: DF.Link | None
+		item_code: DF.Link
 		item_group: DF.Link | None
 		item_name: DF.Data | None
 		parent: DF.Data