fix(agent_session_endpoints): remove unused imports flagged by ruff

Pre-existing F401 violations cleaned up so the lint job stays green:
  * agent_endpoints.py: unused List, Optional from typing
  * cleanup.py: unused SESSION_STATUS_TERMINATED
  * internal_endpoints.py: unused SESSION_TERMINAL_STATUSES
  * session_endpoints.py: unused SESSION_STATUS_READY

Tests still 58/58 green.

litellm/proxy/agent_session_endpoints/agent_endpoints.py

@@ -14,7 +14,6 @@ row is removed.
 
 import asyncio
 from datetime import datetime, timezone
-from typing import List, Optional
 
 from fastapi import APIRouter, Depends, HTTPException, Query
 from fastapi.responses import ORJSONResponse

litellm/proxy/agent_session_endpoints/cleanup.py

@@ -27,7 +27,6 @@ from litellm.proxy.agent_session_endpoints.constants import (
     RUN_STATUS_ERROR,
     SESSION_STATUS_ERROR,
     SESSION_STATUS_PROVISIONING,
-    SESSION_STATUS_TERMINATED,
     SESSION_TERMINAL_STATUSES,
 )
 

litellm/proxy/agent_session_endpoints/internal_endpoints.py

@@ -32,7 +32,6 @@ from litellm.proxy.agent_session_endpoints.constants import (
     RUN_TERMINAL_EVENT_TYPES,
     SESSION_STATUS_PROVISIONING,
     SESSION_STATUS_READY,
-    SESSION_TERMINAL_STATUSES,
 )
 from litellm.proxy.agent_session_endpoints.schemas import (
     DaemonHeartbeatRequest,

litellm/proxy/agent_session_endpoints/session_endpoints.py

@@ -37,7 +37,6 @@ from litellm.proxy.agent_session_endpoints.constants import (
     RUN_STATUS_QUEUED,
     SESSION_STATUS_ERROR,
     SESSION_STATUS_PROVISIONING,
-    SESSION_STATUS_READY,
     SESSION_STATUS_TERMINATED,
     SESSION_TERMINAL_STATUSES,
 )