Refactor/message cycle manage and knowledge retrieval (#20460)

Signed-off-by: -LAN- <laipz8200@outlook.com>

api/core/workflow/graph_engine/entities/event.py

@@ -1,9 +1,10 @@
-from collections.abc import Mapping
+from collections.abc import Mapping, Sequence
 from datetime import datetime
 from typing import Any, Optional
 
 from pydantic import BaseModel, Field
 
+from core.rag.entities.citation_metadata import RetrievalSourceMetadata
 from core.workflow.entities.node_entities import AgentNodeStrategyInit
 from core.workflow.graph_engine.entities.runtime_route_state import RouteNodeState
 from core.workflow.nodes import NodeType
@@ -82,7 +83,7 @@ class NodeRunStreamChunkEvent(BaseNodeEvent):
 
 
 class NodeRunRetrieverResourceEvent(BaseNodeEvent):
-    retriever_resources: list[dict] = Field(..., description="retriever resources")
+    retriever_resources: Sequence[RetrievalSourceMetadata] = Field(..., description="retriever resources")
     context: str = Field(..., description="context")