refactor: Unify NodeConfigDict.data and BaseNodeData (#32780)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

api/dify_graph/graph/graph.py

@@ -8,7 +8,7 @@ from typing import Protocol, cast, final
 from pydantic import TypeAdapter
 
 from dify_graph.entities.graph_config import NodeConfigDict
-from dify_graph.enums import ErrorStrategy, NodeExecutionType, NodeState, NodeType
+from dify_graph.enums import ErrorStrategy, NodeExecutionType, NodeState
 from dify_graph.nodes.base.node import Node
 from libs.typing import is_str
 
@@ -34,7 +34,8 @@ class NodeFactory(Protocol):
 
         :param node_config: node configuration dictionary containing type and other data
         :return: initialized Node instance
-        :raises ValueError: if node type is unknown or configuration is invalid
+        :raises ValueError: if node type is unknown or no implementation exists for the resolved version
+        :raises ValidationError: if node_config does not satisfy NodeConfigDict/BaseNodeData validation
         """
         ...
 
@@ -115,10 +116,7 @@ class Graph:
         start_node_id = None
         for nid in root_candidates:
             node_data = node_configs_map[nid]["data"]
-            node_type = node_data["type"]
-            if not isinstance(node_type, str):
-                continue
-            if NodeType(node_type).is_start_node:
+            if node_data.type.is_start_node:
                 start_node_id = nid
                 break
 
@@ -203,6 +201,23 @@ class Graph:
 
         return GraphBuilder(graph_cls=cls)
 
+    @staticmethod
+    def _filter_canvas_only_nodes(node_configs: Sequence[Mapping[str, object]]) -> list[dict[str, object]]:
+        """
+        Remove editor-only nodes before `NodeConfigDict` validation.
+
+        Persisted note widgets use a top-level `type == "custom-note"` but leave
+        `data.type` empty because they are never executable graph nodes. Filter
+        them while configs are still raw dicts so Pydantic does not validate
+        their placeholder payloads against `BaseNodeData.type: NodeType`.
+        """
+        filtered_node_configs: list[dict[str, object]] = []
+        for node_config in node_configs:
+            if node_config.get("type", "") == "custom-note":
+                continue
+            filtered_node_configs.append(dict(node_config))
+        return filtered_node_configs
+
     @classmethod
     def _promote_fail_branch_nodes(cls, nodes: dict[str, Node]) -> None:
         """
@@ -302,13 +317,13 @@ class Graph:
         node_configs = graph_config.get("nodes", [])
 
         edge_configs = cast(list[dict[str, object]], edge_configs)
+        node_configs = cast(list[dict[str, object]], node_configs)
+        node_configs = cls._filter_canvas_only_nodes(node_configs)
         node_configs = _ListNodeConfigDict.validate_python(node_configs)
 
         if not node_configs:
             raise ValueError("Graph must have at least one node")
 
-        node_configs = [node_config for node_config in node_configs if node_config.get("type", "") != "custom-note"]
-
         # Parse node configurations
         node_configs_map = cls._parse_node_configs(node_configs)