feat(numbering): block direct invoice creation + wire account.move into mixin

Customer invoices (out_invoice / out_refund) can only be created via
sale.order._create_invoices() or with an invoice_origin matching an
existing SO. Applies to ALL users including admins. Once created,
the move's name is derived from the SO's parent number: IN-30000,
IN-30000-02, CN-30000, ... Pre-existing portal-job link on
action_post() preserved.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

fusion_plating/fusion_plating_jobs/models/sale_order.py

@@ -296,6 +296,17 @@ class SaleOrder(models.Model):
                     ) % {'job': job.name, 'err': exc})
         return result
 
+    def _create_invoices(self, grouped=False, final=False, date=None):
+        """Set fp_from_so_invoice=True so account.move.create() allows
+        the customer-invoice creation (the direct-creation block is
+        bypassed via this context flag). Also lets the parent-numbered
+        mixin find the originating SO without depending on invoice_origin.
+        """
+        return super(SaleOrder, self.with_context(
+            fp_from_so_invoice=True,
+            fp_invoice_source_so_id=self.id if len(self) == 1 else False,
+        ))._create_invoices(grouped=grouped, final=final, date=date)
+
     def _fp_resolve_recipe_for_line(self, line):
         """4-tier recipe resolution. Used BOTH for grouping (Task 6
         recipe-driven WO splits) AND for the per-job vals construction.