Please land the process_output/process_exited ordering fix

Problem

agentos-core@0.2.7 ships a workaround in dist/sidecar/rpc-client.js (drainTrailingProcessOutputTurn, see the comment at the top of the file) for native-sidecar process_output events arriving up to one macrotask after process_exited.

A proper fix exists — commit 9555bf756 ("fix(sidecar): order process output before exit", 2026-07-13, includes process-event-ordering.test.ts) — but as far as we can tell it currently lives only on the agent/acp-codex-session-benchmark branch and is not on main / in any released version.

Why it matters to us

We stream agent output token-by-token to end users, and on the previous (JS runtime) architecture we had to patch around adjacent stream-frame reordering ourselves. Event ordering between guest process streams and lifecycle events is load-bearing for us; with the runtime now compiled into the sidecar binary, we have no local mitigation available anymore — we depend on upstream releases for this class of fix.

Start by reviewing dist/sidecar/rpc-client.js and commit 9555bf756, then inspect process-event-ordering.test.ts on the agent/acp-codex-session-benchmark branch. Run that ordering test and check the release workflow; done means the fix is on main and included in a released version.