A turn forcibly interrupted by the drain-timeout escalation never reaches
turn_finalizer.finalize_turn (the only place that flushes the turn to
state.db). Its in-flight tool rounds live only in the in-memory
_session_messages, so the immediate pre-restart turn was silently dropped
from load_transcript() on resume.
_finalize_shutdown_agents now flushes _session_messages to the SQLite
session store before teardown. The flush is idempotent (identity-tracked
in _flush_messages_to_session_db), so agents that finished gracefully
re-flush nothing. The resume_pending / fresh-tool-tail branches in
_handle_message_with_agent already expect a transcript whose tail may be a
pending tool result.
Fixes#13121.
Teknium
d19aabbf2d