Codex + an independent review pass found three real defects in the prior commit:
1. parseExitStatus could misreport a SUCCESSFUL command as a failure: a clean
exit 0 appends no marker, so output ending in "[exit code: 5]" (no trailing
newline) was read as the marker. Anchor the parse to a LEADING newline —
renderResult always inserts one before a real marker, so a body that merely
ends in marker-like text no longer matches. A narrow residual (a clean exit 0
whose final line is exactly the marker) is inherent to the replay-only-sees-
text design and documented; the complete fix (a structured exit on the event)
is the RFC's named escape hatch.
2. A run_in_background start and an isError result were rendered as exited
terminal cards with a false exit-0 pill. A background start returns a task-id
ack (not a streamed terminal) and is no longer marked terminal; an isError
result (spawn failure / abort) carries no exit pill.
3. The terminal capability was re-read live on the result path, so a second
initialize between a call and its result could desync them (orphan
terminal_output or clobbered card). Snapshot the capability per session at
creation (SessionRecord.terminalEnabled) so call and result always agree.
Also reword the reference-parity claim: keeping the description as a content
block in terminal mode is a DELIBERATE divergence (claude-agent-acp drops it).
Tests added for each; with-key e2e still green.
Tianyi Cui
9f6b96c555