feat: Add automatic lot number generation for stock picking move lines based on product template sequences.

models/__init__.py

@@ -2,4 +2,5 @@ from . import product_template
 from . import stock_move
 from . import stock_lot
 from . import stock_move_line
-from . import mrp_production
+from . import mrp_production
+from . import stock_picking

models/stock_picking.py

@@ -0,0 +1,34 @@
+from odoo import models
+
+class StockPicking(models.Model):
+    _inherit = 'stock.picking'
+
+    def action_auto_generate_lots_subcontract(self):
+        """
+        Auto-generate lot names for move lines in this picking that:
+        1. Have a product with tracking enabled (serial or lot).
+        2. Have an empty 'lot_name' and no 'lot_id'.
+        3. Have a product template with a configured 'lot_sequence_id'.
+        """
+        for picking in self:
+            # We iterate over move_line_ids (operations)
+            # Filter for lines that need a lot generated
+            lines_to_process = picking.move_line_ids.filtered(
+                lambda ml: (
+                    ml.product_id 
+                    and ml.product_id.tracking in ('serial', 'lot')
+                    and not ml.lot_name 
+                    and not ml.lot_id
+                    and getattr(ml.product_id.product_tmpl_id, 'lot_sequence_id', False)
+                )
+            )
+
+            for line in lines_to_process:
+                # Get the sequence from the product template
+                seq = line.product_id.product_tmpl_id.lot_sequence_id
+                if seq:
+                    # strict=True ensures we skip if next_by_id fails, though usually it returns None/False
+                    new_lot_name = seq.next_by_id()
+                    if new_lot_name:
+                        line.lot_name = new_lot_name
+        return True