[IMP] website_sale_aplicoop: propagate consumer_group_id directly from group_order

- Add consumer_group_id to sale.order for tracking the consumer group
- Fix stock.picking consumer_group_id to use sale_id.consumer_group_id
- Add group_ids inverse relation in res.partner for bidirectional access
- Remove auto-calculation of consumer_group_id, data comes directly from group_order.group_ids[0]
- Add debug logging for consumer_group propagation
- commitment_date propagates directly from group_order (no recalculation)

website_sale_aplicoop/models/res_partner_extension.py

@@ -18,14 +18,26 @@ class ResPartner(models.Model):
     )
 
     # Relación para los miembros de un grupo (si is_group es True)
+    # Este campo se usa en el GRUPO para listar sus MIEMBROS
     member_ids = fields.Many2many(
         "res.partner",
         "res_partner_group_members_rel",
         "group_id",
         "member_id",
+        string="Members",
+        help="Members that belong to this consumer group",
+    )
+
+    # Relación inversa: grupos a los que pertenece un MIEMBRO
+    # Este campo se usa en el MIEMBRO para listar sus GRUPOS
+    group_ids = fields.Many2many(
+        "res.partner",
+        "res_partner_group_members_rel",
+        "member_id",
+        "group_id",
         domain=[("is_group", "=", True)],
         string="Consumer Groups",
-        help="Consumer Groups this partner belongs to",
+        help="Consumer groups this partner belongs to",
     )
 
     # Inverse relation: group orders this group participates in