Codex review of the trace-event fold found two merge-blockers.
Blocker #1 — format version. Folding usage onto assistant/message and removing
the standalone usage/error events changed the persisted SessionEventMap shape,
which per the AGENTS.md "bump the version and reject — don't migrate" policy
requires a backend to reject any non-current log. Centralize the version in an
exported SESSION_FORMAT_VERSION constant (dsh-session), read by both write sites
(Session constructor default, SessionStore.prepare header) and the coordinator's
load-time assertVersion check. The constant is pinned at 0: while unreleased the
on-disk format is unstable/pre-release, so breaking shape churn is absorbed at v0
(no monotonic bump until the first tagged release) and any non-0 log is rejected
on load — no migration. Update every test/fixture/doc that stamps a
currently-written header to the constant, bump the ACP snapshot fixture + golden
headers to v0, and keep the version-rejection test meaningful by switching its
bad value to a clearly non-current 99. AGENTS.md documents both the monotonic
(SQLite SCHEMA_VERSION) and pinned-0 (session log) pre-release stances.
Blocker #2 — restore the late turn-end warn. failTurn now sets the error reason
only while the turn is still open; once turn/end is appended (a throwing
agent/turn-end listener after closeTurn) the reason can no longer reach the
durable log, so the late throw is logged via ctx.logger.warn instead of
vanishing into a futile post-close assignment. A regression test asserts the
warn fires.
Also guard the normal-step assistant/message append with the same
content-or-usage condition as the max-tokens branch (a content-less, usage-less
step records no trace-only row), with a covering test.
Adds the snapshot-test harness and the keyless replay pipeline end-to-end.
- snapshot-harness.ts: boots the real acp-agent subprocess via the cordis
Loader (preserving TSX_TSCONFIG_PATH so unbuilt dsh-* imports resolve from a
temp cwd), tees raw stdout into an SDK ClientSideConnection, interprets a
per-scenario input.json DSL (initialize / newSession capturing the random
sessionId / prompt / cancel), closes stdin to trigger graceful shutdown, and
harvests the persisted session.jsonl. Failure-safe: a finally block SIGKILLs
a live child, awaits its exit, and removes both temp dirs even on a thrown
step or harvest. Raw bytes are buffered and decoded once (no multibyte split).
- snapshot-normalize.ts (+ spec): two pure normalizers (stdout frames + session
JSONL) scrub cwd, session ids / UUIDs, and JSON-RPC ids, and zero time /
createdAt — but keep `seq` (deterministic by contract). normalizeStdout throws
on a non-JSON line (the stdout-purity check).
- start.ts: selects cordis.snapshot.yml (replay, providerless) or
cordis.snapshot-record.yml (record, real adapter) from DSH_SNAPSHOT, skips
.env in replay, and disposes the ctx on stdin end so persistence flushes
before exit (harvest-after-flush, not on the prompt response).
- acp.snapshot.ts: asserts the normalized stdout golden (and, for model
scenarios, the re-persisted JSONL golden) via toMatchFileSnapshot; record mode
writes the harvested log back to the scenario fixture; an orphan-fixture guard
fails on an unregistered scenario dir.
- handshake scenario: initialize + session/new (no model call; a header-only
session.jsonl, since session/new persists no events).
- vitest.snapshot.config.ts, test:snapshot / test:snapshot:record scripts, a
pre-push snapshot job, and the knip entry.
Incorporates Codex review: record-fixture writeback, failure-safe teardown,
seq-not-scrubbed, harvest-after-flush. Per docs/rfc/implemented/2026-06-19.
