const TSIDX_FILENAME: &str;Expand description
Receive-time sidecar (see agent_session::TSIDX_FILE) — archived,
deleted, and restored in lockstep with output (codex P2 on PR #2508):
leaving it behind would mis-time a fresh session’s lines (new output
restarts at offset 0 under stale entries), and dropping it from the
archive loses the timestamps the sidecar exists to preserve.