Fixed all ruff lint and formatting errors

surfsense_backend/app/agents/researcher/qna_agent/state.py

@@ -3,14 +3,16 @@
 from __future__ import annotations
 
 from dataclasses import dataclass, field
-from typing import List, Optional, Any
+from typing import Any
+
 from sqlalchemy.ext.asyncio import AsyncSession
 
+
 @dataclass
 class State:
     """Defines the dynamic state for the Q&A agent during execution.
 
-    This state tracks the database session, chat history, and the outputs 
+    This state tracks the database session, chat history, and the outputs
     generated by the agent's nodes during question answering.
     See: https://langchain-ai.github.io/langgraph/concepts/low_level/#state
     for more information.
@@ -18,8 +20,8 @@ class State:
 
     # Runtime context
     db_session: AsyncSession
-    
-    chat_history: Optional[List[Any]] = field(default_factory=list)
+
+    chat_history: list[Any] | None = field(default_factory=list)
     # OUTPUT: Populated by agent nodes
-    reranked_documents: Optional[List[Any]] = None
-    final_answer: Optional[str] = None
+    reranked_documents: list[Any] | None = None
+    final_answer: str | None = None