feat(plating): B1 - recipe walker _fp_all_nodes_with_kind for Express Orders

fusion_plating/fusion_plating/models/fp_process_node.py

@@ -738,6 +738,25 @@ class FpProcessNode(models.Model):
 
     # ---- Actions -------------------------------------------------------------
 
+    # ---- Express Orders helper (2026-05-26) ----
+    def _fp_all_nodes_with_kind(self, kinds):
+        """Return all descendants (and self) where default_kind ∈ kinds.
+
+        Uses _parent_store's parent_path for a single SQL hit via the
+        'child_of' operator. No Python tree walking.
+
+        :param kinds: tuple/list of default_kind strings, e.g.
+                      ('masking', 'de_masking') or ('baking',)
+        :return: recordset of matching fusion.plating.process.node rows
+        """
+        self.ensure_one()
+        if not kinds:
+            return self.browse([])
+        return self.search([
+            ('id', 'child_of', self.id),
+            ('default_kind', 'in', list(kinds)),
+        ])
+
     def action_open_tree_editor(self):
         """Open the OWL recipe tree editor for this recipe."""
         self.ensure_one()