refactor(typing): Fixup typing A2 - workflow engine & nodes (#31723)

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Asuka Minato <i@asukaminato.eu.org>

api/models/workflow.py

@@ -29,6 +29,7 @@ from core.workflow.constants import (
     CONVERSATION_VARIABLE_NODE_ID,
     SYSTEM_VARIABLE_NODE_ID,
 )
+from core.workflow.entities.graph_config import NodeConfigDict, NodeConfigDictAdapter
 from core.workflow.entities.pause_reason import HumanInputRequired, PauseReason, PauseReasonType, SchedulingPause
 from core.workflow.enums import NodeType
 from extensions.ext_storage import Storage
@@ -229,7 +230,7 @@ class Workflow(Base):  # bug
         # - `_get_graph_and_variable_pool_for_single_node_run`.
         return json.loads(self.graph) if self.graph else {}
 
-    def get_node_config_by_id(self, node_id: str) -> Mapping[str, Any]:
+    def get_node_config_by_id(self, node_id: str) -> NodeConfigDict:
         """Extract a node configuration from the workflow graph by node ID.
         A node configuration is a dictionary containing the node's properties, including
         the node's id, title, and its data as a dict.
@@ -247,8 +248,7 @@ class Workflow(Base):  # bug
             node_config: dict[str, Any] = next(filter(lambda node: node["id"] == node_id, nodes))
         except StopIteration:
             raise NodeNotFoundError(node_id)
-        assert isinstance(node_config, dict)
-        return node_config
+        return NodeConfigDictAdapter.validate_python(node_config)
 
     @staticmethod
     def get_node_type_from_node_config(node_config: Mapping[str, Any]) -> NodeType: