feat(workflow): support Dify features conversion and file variable migration

api/app/services/app_service.py

@@ -411,6 +411,7 @@ class AppService:
             edges=[edge.model_dump() for edge in data.edges] if data.edges else [],
             variables=[var.model_dump() for var in data.variables] if data.variables else [],
             execution_config=data.execution_config.model_dump() if data.execution_config else {},
+            features=data.features if data.features else {},
             triggers=[trigger.model_dump() for trigger in data.triggers] if data.triggers else [],
             is_active=True,
             created_at=now,

api/app/services/workflow_import_service.py

@@ -69,6 +69,7 @@ class WorkflowImportService:
             edges=workflow_config.edges,
             nodes=workflow_config.nodes,
             variables=workflow_config.variables,
+            features=workflow_config.features,
             warnings=workflow_config.warnings,
             errors=workflow_config.errors
         )
@@ -95,7 +96,8 @@ class WorkflowImportService:
                 workflow_config=WorkflowConfigCreate(
                     nodes=config["nodes"],
                     edges=config["edges"],
-                    variables=config["variables"]
+                    variables=config["variables"],
+                    features=config.get("features", {})
                 )
             )
         )