[IMP] stock_picking_batch_custom: order detailed ops by category, product, partner

Store picking_partner_id on stock.move.line and set default_order to
product_categ_complete_name, product_id, picking_partner_id in the
detailed operations view so sorting uses the full category path
(e.g. 'SECO ENVASADO / Aperitivos') instead of only the leaf name.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

stock_picking_batch_custom/models/stock_move_line.py

@@ -17,6 +17,13 @@ class StockMoveLine(models.Model):
         readonly=True,
     )
 
+    product_categ_complete_name = fields.Char(
+        string="Product Category Path",
+        related="product_id.categ_id.complete_name",
+        store=True,
+        readonly=True,
+    )
+
     product_default_code = fields.Char(
         string="Product Code",
         related="product_id.default_code",