fix(plating): order-level Lot Order toggle replaces per-line lot checkbox

Express order entry now has a single "Lot Order" toggle on the header
instead of a per-line "Lot" checkbox. When on, every line shows Lot
Total and prices as a flat lot (unit price derived = lot total / qty,
qty preserved for production); when off, the Lot Total column is hidden
and lines price per unit as usual. Keeps the order summary clean for the
common per-unit case.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

fusion_plating/fusion_plating_configurator/wizard/fp_direct_order_line.py

@@ -238,20 +238,17 @@ class FpDirectOrderLine(models.Model):
         string='Unit Price',
         currency_field='currency_id',
     )
-    is_lot_priced = fields.Boolean(
-        string='Lot Price',
-        help='Price the whole quantity as a flat lot total instead of '
-             'per unit. Unit price is derived = lot total / quantity; '
-             'the quantity is preserved for production.',
-    )
     lot_total = fields.Monetary(
         string='Lot Total', currency_field='currency_id',
+        help='Flat total for the whole line quantity when the order is a '
+             'lot order. Unit price is derived = lot total / quantity; '
+             'the quantity is preserved for production.',
     )
 
-    @api.onchange('is_lot_priced', 'lot_total', 'quantity')
+    @api.onchange('lot_total', 'quantity')
     def _onchange_lot_pricing(self):
         for line in self:
-            if line.is_lot_priced and line.quantity:
+            if line.wizard_id.is_lot_order and line.quantity:
                 line.unit_price = (line.lot_total or 0.0) / line.quantity
     line_subtotal = fields.Monetary(
         string='Subtotal',

fusion_plating/fusion_plating_configurator/wizard/fp_direct_order_wizard.py

@@ -336,6 +336,22 @@ class FpDirectOrderWizard(models.Model):
             if rec.charge_type_id and not rec.charge_amount:
                 rec.charge_amount = rec.charge_type_id.default_amount
 
+    is_lot_order = fields.Boolean(
+        string='Lot Order',
+        help='Price the order as flat lots instead of per unit. When on, '
+             'each line takes a Lot Total and the unit price is derived = '
+             'lot total / quantity; the quantity is preserved for '
+             'production. When off, lines price per unit as usual.',
+    )
+
+    @api.onchange('is_lot_order')
+    def _onchange_is_lot_order(self):
+        for rec in self:
+            if rec.is_lot_order:
+                for line in rec.line_ids:
+                    if line.quantity:
+                        line.unit_price = (line.lot_total or 0.0) / line.quantity
+
     # ---- PO status pill (computed, display-only) ----
     po_status = fields.Selection(
         [('received', 'Received'),
@@ -403,8 +419,8 @@ class FpDirectOrderWizard(models.Model):
     @api.depends(
         'line_ids.quantity',
         'line_ids.unit_price',
-        'line_ids.is_lot_priced',
         'line_ids.lot_total',
+        'is_lot_order',
         'charge_amount',
         'tooling_charge',
         'tax_id',
@@ -420,11 +436,13 @@ class FpDirectOrderWizard(models.Model):
         at action_create_order time (so it carries into the invoice).
         """
         for rec in self:
-            subtotal = sum(
-                (l.lot_total or 0.0) if l.is_lot_priced
-                else (l.quantity or 0) * (l.unit_price or 0.0)
-                for l in rec.line_ids
-            )
+            if rec.is_lot_order:
+                subtotal = sum(l.lot_total or 0.0 for l in rec.line_ids)
+            else:
+                subtotal = sum(
+                    (l.quantity or 0) * (l.unit_price or 0.0)
+                    for l in rec.line_ids
+                )
             charge = rec.charge_amount or rec.tooling_charge or 0.0
             tax_total = 0.0
             if rec.tax_id and (subtotal + charge):
@@ -858,7 +876,7 @@ class FpDirectOrderWizard(models.Model):
                 'product_uom_qty': line.quantity,
                 'price_unit': (
                     (line.lot_total / line.quantity)
-                    if line.is_lot_priced and line.quantity
+                    if self.is_lot_order and line.quantity
                     else (line.unit_price or 0.0)
                 ),
                 'x_fc_part_catalog_id': part.id,
@@ -904,7 +922,7 @@ class FpDirectOrderWizard(models.Model):
                 # NB. Odoo 19 renamed the SO line field to tax_ids.
                 'tax_ids': ([(6, 0, self.tax_id.ids)]
                             if self.tax_id else False),
-                'x_fc_is_lot_priced': line.is_lot_priced,
+                'x_fc_is_lot_priced': self.is_lot_order,
                 'x_fc_lot_total': line.lot_total or 0.0,
             }))