feat(bridge_mrp): Sub 3 — _resolve_mo_process_tree helper; walker prefers part-cloned tree (Task 3)

fusion_plating/fusion_plating_bridge_mrp/models/mrp_production.py

@@ -495,8 +495,8 @@ class MrpProduction(models.Model):
         """
         WorkOrder = self.env['mrp.workorder']
         for production in self:
-            if not production.x_fc_recipe_id:
-                continue  # No recipe assigned
+            if not production._resolve_mo_process_tree():
+                continue  # No recipe / part tree assigned
             if production.workorder_ids:
                 continue  # WOs already exist — don't duplicate
 
@@ -679,7 +679,11 @@ class MrpProduction(models.Model):
                 # 'step' nodes at top level are handled by their parent operation
 
             # Start walking from recipe root
-            walk_node(production.x_fc_recipe_id)
+            # Sub 3 — resolve via helper (part-cloned tree preferred,
+            # recipe_id fallback)
+            root = production._resolve_mo_process_tree()
+            if root:
+                walk_node(root)
 
             # Bulk create work orders
             if wo_vals_list:
@@ -699,7 +703,7 @@ class MrpProduction(models.Model):
                         )
                 production.message_post(
                     body=_('%d work orders generated from recipe "%s".') % (
-                        len(wo_vals_list), production.x_fc_recipe_id.name),
+                        len(wo_vals_list), (root.name if root else '')),
                 )
 
     # ------------------------------------------------------------------
@@ -1146,6 +1150,37 @@ class MrpProduction(models.Model):
             'target': 'current',
         }
 
+    # ------------------------------------------------------------------
+    # Sub 3 — Process tree resolution (single source for WO walker)
+    # ------------------------------------------------------------------
+    def _resolve_mo_process_tree(self):
+        """Resolve which process-tree root to walk for this MO.
+
+        Sub 3 — prefers the linked part's cloned tree
+        (SO line's x_fc_part_catalog_id.default_process_id); falls back
+        to the legacy x_fc_recipe_id for MOs without a linked part or
+        without a composed part tree.
+
+        Single entry point so Sub 4 / Sub 5 updates touch one method.
+        """
+        self.ensure_one()
+        # Resolve part via SO lines (MO's origin → sale.order → first
+        # line's part). mrp.production has no direct part link; the
+        # relationship lives on sale.order.line.
+        part = False
+        if self.origin:
+            so = self.env['sale.order'].search(
+                [('name', '=', self.origin)], limit=1,
+            )
+            if so and so.order_line:
+                first_line = so.order_line[0]
+                if 'x_fc_part_catalog_id' in first_line._fields:
+                    part = first_line.x_fc_part_catalog_id
+        if part and part.default_process_id:
+            return part.default_process_id
+        # Fallback — legacy recipe lookup (coating config / product match)
+        return self.x_fc_recipe_id
+
     # ------------------------------------------------------------------
     # Sub 2 — Certificate requirement resolution (single source)
     # ------------------------------------------------------------------