fix: load paginated run history messages (#3305)

backend/app/gateway/routers/thread_runs.py

@@ -21,6 +21,7 @@ from pydantic import BaseModel, Field
 
 from app.gateway.authz import require_permission
 from app.gateway.deps import get_checkpointer, get_current_user, get_feedback_repo, get_run_event_store, get_run_manager, get_run_store, get_stream_bridge
+from app.gateway.pagination import trim_run_message_page
 from app.gateway.services import sse_consumer, start_run, wait_for_run_completion
 from deerflow.runtime import RunRecord, RunStatus, serialize_channel_values
 
@@ -402,8 +403,7 @@ async def list_run_messages(
         before_seq=before_seq,
         after_seq=after_seq,
     )
-    has_more = len(rows) > limit
-    data = rows[:limit] if has_more else rows
+    data, has_more = trim_run_message_page(rows, limit=limit, after_seq=after_seq)
     return {"data": data, "has_more": has_more}