The local PTY readiness poll held its inferred_idle fallback for exactly
one pollIntervalMs after a prompt marker, so a bash foreground handoff
that lands on the silence boundary only wins the exact stdin_read
attribution when the kernel publishes it inside that single poll. On a
slow or loaded host it does not, and the attribution flips.
handoffGraceMs replaces the hardcoded one-poll window as a validated,
deployment-owned config field defaulting to 500ms, rejected at load when
it cannot contain one readiness poll. Real-shell tests that interrupt a
send now assert the session is usable again rather than which readiness
tier observed the handoff, because no fixed grace removes the race.
The darwin-parity job failed intermittently on the SIGINT test with the
operation buffer holding only the echoed command line, never RAW_READY. The
harness sets idleSilenceMs to 250, so when a cold python3 start stays silent
past that bound the send settles as inferred_idle; PtySendOperation.append then
drops all later output, and the marker reaches only the scrollback.
Give the harness per-test idleSilenceMs/timeoutMs overrides and let this
scenario raise both above interpreter startup latency, so the readiness marker
lands inside the send it belongs to. waitForOutput's own deadline and the test
timeout grow to match the new bounds.
The product timings are unchanged; the pty Agent Note records why a test that
waits on an operation must outlast the child's startup.
Add a branded AgentMessageId assigned to each accepted send message and
returned from send/followup/steer/inject (was void). Rename the inbox
event payload InboxItemInfo to AgentMessage, carrying that id so a caller
can correlate a queued item with its enqueue/dequeue/discard events.
Replace send/steer/inject with one Agent.send primitive over the
(target × wakeup) matrix; followup/steer/inject become fixed-preset
alias methods on the now-abstract Agent class. Coalesce context/message
into user/message (injected context is a non-user source). Replace
agent/queued with agent/inbox/enqueue/dequeue/discard, add cancel
keepInbox, and add a FIFO-conservation invariant.
Chinesezjc