fix: product_category tree root node query + parent_id normalization - get_product_category: accept NULL/empty/'0' as root (parent_id IS NULL OR '' OR '0') - new_product_category: normalize empty/0 parent_id to NULL

wwwroot/product_category_tree/get_product_category.dspy

@@ -2,12 +2,12 @@
 ns = params_kw.copy()
 sql = '''select * from product_category where 1 = 1'''
 id = ns.get('id')
-if id:
+if id and id != '0' and id != 'null' and id != 'undefined':
 	sql += " and parent_id = ${id}$"
 else:
-	sql += " and parent_id is null"
+	sql += " and (parent_id is null or parent_id = '' or parent_id = '0')"
 
-sql += " order by name "
+sql += " order by sort_order, name "
 db = DBPools()
 dbname = get_module_dbname('product_management')
 async with db.sqlorContext(dbname) as sor:

wwwroot/product_category_tree/new_product_category.dspy

@@ -1,15 +1,19 @@
 
 ns = params_kw.copy()
 for k,v in ns.items():
-	if v == 'NaN' or v == 'null':
+	if v == 'NaN' or v == 'null' or v == 'undefined' or v == '':
 		ns[k] = None
-id = params_kw.id
+
-if not id or len(id) > 32:
+# Normalize parent_id: empty/0/None all mean root node (NULL)
+pid = ns.get('parent_id')
+if not pid or pid == '0':
+	ns['parent_id'] = None
+
+id = params_kw.get('id')
+if not id or len(str(id)) > 32:
 	id = uuid()
 ns['id'] = id
 
-
-
 userorgid = await get_userorgid()
 if not userorgid:
 	return {