Merge 3ea52fc3e475a3e7c430812bde4209258416e57b into a0a61a8237f61344a01448a97954df603d8fff73. Retain the V2-to-V3 migration dependency alongside native system flock support, removing the replaced fs-ext dependency. Union the lockfile workspace importer entries; frozen installation validates the result without regeneration.
Preserve release publint async lane-signal cancellation, close ownership, and spawn-error regressions, satisfying the incoming CI budget intent. Keep canonical, prompt, preset, and latest migration regression behavior. Rename an arbitrary preset fixture value to custom-agent to avoid the inherited vendor-rescope false positive without changing test semantics.
Validation: frozen install; full build including Darwin addon; focused V3/persistence/prompt/publint and runtime tests; built migration, two-process lease, and loader smokes; native flock and package-matrix tests; touched dependency and CI owner tests; all hygiene leaves (vendor residue repaired and rechecked); doc-sync 34/34.
Observe actual shared-preparation waiter admission and settle both callers before cleanup, preserving current V3 migration expectations. Adopt master’s cross-platform teardown regressions without changing budgets or Session data.
Keep the synthetic compressed historical fixture step-first without changing frozen generation data or shared fixtures. Pin its migrated empty system head and unchanged source bytes. Exercise malformed native system rows before and after recoverable damage through scanner and read/write handles. Remove the unreachable duplicate unsupported-format catch after current-row admission; preserve its owned rejection and generic error path.
Validation: original zstd regression red; admission-bypass negative control 3/3 red; five focused specs 314/314 pass with format.ts 100% statements/branches/functions/lines. Final admission cleanup 15/15 pass. Full build-backed lint found one matcher typing error; exact identifier oracle replaces it and focused type-aware lint passes.
Compose the shared release branch PTC rename with the structural system-head migration in the existing V2-to-V3 stage. Audit source payloads and remap local coordinates before renaming dispatch vocabulary and owned plugin attribution; retain original message identities and generation-qualified references. Native V3 validation combines the same system and PTC lifecycle semantics through a private released-validation view.
Reuse the V3 row-admission owner in current JSONL scanning before recoverable-tail suppression, so malformed rows cannot hide retired required PTC tags or header.system. The new corruption-prefix regressions and all173 existing JSONL scanner tests pass. Combined migration/catalog/persistence suite:300 tests; executable V3 migration source has100% coverage. No released generation, prior migration implementation, shared release branch, benchmark or CI workflow is modified by this integration.
Treat Vitest asymmetric matchers as unknown expected values and spell void assertion callbacks explicitly. This preserves the migration identity and refusal checks under the full type-aware lint configuration without relaxing validation or suppressing a rule.
Construct supported historical inputs with the first surface inside step/start instead of weakening publication, singleflight, packed-row, and read-handoff assertions into refusal cases. Account for the inserted empty system head and shifted event sequence when V2 rows become V3; preserve exact native V3 expectations and original source bytes.
Current V3 promotion must preserve chronology, so historical user surfaces before the first step are unsupported. Assert refusal for read and write opens, preserve source bytes and identity, and forbid intermediate or current publication. Frozen codec validation remains in its existing owner tests; V2 no-downgrade coverage lives in v2-system-migration.spec.ts.
The migrating first open measured 1,963 ms on the CI runner under the
128 MB heap limit; 4,000 ms keeps a 2x margin while the repeated-snapshot
implementation still fails by heap exhaustion and would need ~10 s.
The migrating first open of the synthetic log costs about 1 s on the
reference machine under the 128 MB heap limit and about twice that on the
CI runner, so 3,000 ms keeps headroom while staying far below the ~5 s
(~10 s on CI) of the repeated-snapshot implementation.
Add a benchmark lane (`vitest.bench.config.ts`, `pnpm run test:bench`,
gate mode `ci-bench`) and a required `node 24 / benchmarks` CI job that
runs it alone. Benchmarks synthesize their input in-process from fixed
parameters and fail on documented budgets:
- `open-generation.bench.ts`: a 200-turn released-v0 log with 500 text
and 125 reasoning deltas per reply (127,400 events, ~2.8 MB) encoded
through the frozen v0 codec; the migrating first `open()` must finish
within 2,000 ms in a child process capped at 128 MB of old space, and a
fresh process must open the published current generation within 500 ms.
- `conversation-fold.bench.client.ts`: 200 replies whose compact streams
hold 2,000 text + 500 reasoning deltas each, folded through every Chat
Definition by the real assembler; the fold must finish within 150 ms
and stay within 3x the fold of the same window with 100 deltas per
reply.
On this commit both gates fail: the migration exhausts the 128 MB heap
(4.8 s and 696 MB peak RSS without the cap; the pre-stack decode of the
same bytes took 34 ms and 168 MB) and the fold scales 11x with the delta
count. The stacked fixes bring both paths to O(records).
Write handles now hold a durable lease (session.lock.json beside the
log): a random owner token, diagnostic pid, and an expiry. Acquisition
wins by exclusive create; a second process's create or write open rejects
while the record is unrenewed for less than leaseTtlMs (default 5 min),
and takes over after that — a crashed holder is waited out, never
reclaimed by pid. The holder renews every leaseRenewIntervalMs (default
4 min); a renewal that finds a foreign, vanished, or expired record — or
fails outright — marks the lease lost permanently, so every later
append/flush rejects with SessionOwnershipLostError while reads continue.
Close releases the record; read handles never touch it. Takeover of an
expired record is eventually exclusive: a replaced holder stops within
one renewal interval.
Refs #3245
`session[.vN].jsonl` was assembled independently by the JSONL provider
(twice), the session-log export archive, and the recorded-session fixture
helpers. `dsh-session-format` now owns `sessionFormatLogFilename` and
`parseSessionFormatLogFilename`; the three consumers append only their
compression suffix, and the migration note names the owner.
`snapshotSessionFormatJson` re-implemented the lossless JSON walk that
`dsh-util-values` already publishes as `snapshotJsonValue` + `deepFreeze`,
and the frozen v0 relationship validator carried a third structural JSON
comparison next to `deepEqualJson`. Both now delegate; the format package
reports one `is not lossless JSON` diagnostic per labelled subject instead
of ten member-specific ones, and enumerable accessors whose values survive
a JSON round trip are accepted like `JSON.stringify` accepts them.
The JSONL backend rethrows storage errno failures and abort signals from the
source read of a pending migration unwrapped; a test now drives both through
the stat seam so the classification stays covered. The navigation-panes Web
e2e derives the exported archive entry from `SESSION_FORMAT_VERSION`, which
`session-log-export` uses for its `session.v<N>.jsonl` name. The module graph
records the `session-log-export` → `session` peer edge.
`ensureJsonlGenerationCurrent` returned a live Zstandard body iterator that
every production caller disposed unread before decoding the same bytes again;
the header read now decodes only the first frame and owns no decoder past its
return. The JSONL backend reuses the generation module's stable-revision read
instead of keeping a second copy, `encodeCurrent` encodes the validated
current artifact it is documented to receive instead of re-running the
migration chain on it, and the test-only `inspectVersion` catalog method and
the `migrateSessionSnapshotFixture` duplicate of
`prepareSessionSnapshotFixtureForComparison` are removed.
Tianyi Cui