Review fix (ds-review-bot critical #2 on #623): the first-turn event stamp
had a durability hole no turn anchoring can close — an idle SessionStart-
style injection persists a complete one-shot turn before any prompt turn
opens, so a crash in that window left a resumable-looking child with no
inherited policy, falling back to a possibly wider deployment default.
The captured overrides now ride the child's creation meta into its
immutable SessionHeader (sandboxMode/approvalPolicy, neutral strings at the
session boundary — the delegationDepth precedent), durable from the moment
the session exists: no listener ordering can starve the baseline and no
crash window can lose it. overrideOf(session) on both policy services
resolves fold(events past header.seedLength) ?? header baseline, validating
against the closed vocabulary on read; stampOverride and the prompt-submit
listener machinery are deleted. The header field rides both persistence
backends (JSONL header line; SQLite sessions columns, SCHEMA_VERSION 11 —
pre-release, no migration). pty-local reads through overrideOf so PTY
spawns see the baseline too.
Red-first: header-durability-before-any-turn test (the injection crash
window shape), baseline/seed-boundary/closed-vocabulary contract tests in
both service suites; the real-wall suite (race, veto, fork stale-seed,
grandchild) re-anchored on header assertions and green. The Agent Note's
Alternatives now records the superseded event-stamping iteration with the
review evidence; bilingual docs updated.
Review fixes (ds-review-bot on #623):
- Capture-at-delegation: the driver now reads overrideOf(parent.session)
for both knobs synchronously before its first await, and the prompt-submit
listener stamps those captured values — a parent switch racing the child's
asynchronous creation belongs to the parent's future, not the child. The
inheritOverride(parent, child) service method is split into its two halves
(overrideOf / stampOverride) accordingly.
- Veto safety: the one-shot prompt-submit listener registers with
prepend: true, so a veto-capable listener (a denying UserPromptSubmit
hook) cannot close the child's first turn without the durable stamp.
Both regressions are pinned red-first in inheritance.spec.ts: the
delegation-vs-late-switch race (delegate tool flips the caller wider while
the creation transaction is pending) and a blocking prompt-submit listener
(stamp survives a promptless first turn). Service contract tests renamed to
the split API; READMEs and the bilingual Agent Note updated.
Per-session policy overrides (sandbox/mode, approval/policy) never crossed
the delegation boundary: a spawn child of a read-only-switched parent ran
under the wider deployment default, and a fork child missed any switch made
after its seed boundary — delegation was a bypass channel for a user's
tightening.
The in-process driver now snapshots the delegating parent's override chain
and stamps it onto the child through the canonical write paths
(SandboxPolicyService.inheritOverride / ApprovalService.inheritOverride),
anchored inside the child's first turn via a one-shot agent/prompt-submit
listener: turn-enclosed (durable), ahead of the first request (an inherited
'never' reaches the child's first system prompt), and positioned after any
stale fork-seed switch so the ordinary last-event-wins fold resolves it.
Only overrides are copied — an unswitched parent stamps nothing and the
child follows the live deployment default; both services are consumed
opportunistically, so compositions without them delegate unchanged. Nesting
composes by construction (each stamp folds the already-stamped parent log).
Evidence: inheritance.spec.ts drives scripted-model children into the real
dsh-fs-sandbox fence through the real write tool (disk-state + denial-marker
assertions; spawn, stale-seed fork, grandchild, escalation fail-closed, and
no-stamp guards), inheritOverride contract tests in both service suites, and
the recorded subagent-sandbox-inheritance ACP snapshot (read-only preset →
delegate → child denied, replayed keylessly).
See .agents/notes/implemented/feature/2026-07-25-subagent-policy-inheritance.md.
The earlier fix only widened the vitest timeout, but the real race is the
patient probe reading the 1s launcher under the 5000ms *default* probe budget:
under a full parallel run spawnSync blocks the worker and fork/exec latency can
push the launcher's wall-clock past 5000ms, so the patient probe wrongly reads
unusable and the assertion fails. Give the patient probe a generous explicit
15000ms budget (still far below its 1s launcher runtime margin) so only the
250ms impatient probe races the launcher; keep a 30s vitest timeout above the
patient budget.
`bounds the default probes` runs a real launcher that sleeps 1s under the
5000ms default probe budget, all wrapped in vitest's 5000ms default test
timeout. The blocking spawnSync races that wrapper and tips over under the
load spike of a full parallel run — a pre-existing, load-sensitive flake
(noted as unrelated in this PR's original description). Give the test an
explicit 20s timeout so its bounded subprocess work never races the default.
- fs-sandbox: delegate the mutation with the freshly re-canonicalized target
(not the stale one), so the checked identity is the mutated identity — a
symlink swapped in after resolve() can no longer escape workspace-write.
- tool-fs: map a denial to an FsError carrying FS_SANDBOX_DENIED (not a plain
Error), so ToolRegistry keeps the structured code on result.error for
retry/observers while the message stays the shared marker.
- sandbox-local: derive the Seatbelt writable set from the shared
writableRoots() helper, so the profile and the fs fence cannot drift.
- gen-doc-graphs: ctx.sandboxPolicy is owned by dsh-sandbox-policy and read only
by the sandboxed executor/provider (the tool layers use the pure fold).
- docs: bash-sandbox/bash/permission READMEs and bash.md reflect the relocated
policy home and the sandbox/mode rename; drop the stale stdout.golden.jsonl.
Extend SandboxMode enforcement from bash to the filesystem tools, the sandbox
RFC's deferred cross-family phase.
- dsh-sandbox-policy (new, ctx.sandboxPolicy): the single home for the
deployment default mode + workspaceRoot and the per-session override event,
renamed bash/sandbox-mode -> sandbox/mode and moved here with its fold/setter.
Decouples the bash seam from dsh-session.
- dsh-fs-sandbox (new): SandboxedFileSystem extends LocalFileSystem and fences
write/edit by the per-call mode (read-only denies, workspace-write contains to
the workspace + temp roots via the shared writableRoots, danger passes
through); reads pass through. Structured FS_SANDBOX_DENIED; in-lock parent
re-canonicalization. A policy fence in trusted code, not a kernel boundary.
- dsh-sandbox: the shared escalation kit (writableRoots, the strictly-wider
ladder, denial/hint markers, approveEscalation) both tool families use;
approveEscalation takes a structural approver so dsh-sandbox gains no
approval/agent dependency, and both tools stay duplication-free.
- tool-fs: write/edit advertise sandbox_permissions/justification under a
confining ctx.fs, map FS_SANDBOX_DENIED to the shared [sandbox: ...] marker,
and resolve the same one-approved-wider retry.
- examples/acp-agent: composes sandbox-policy + fs-sandbox, drops the gating
that disabled the fs stack under confined modes.
RFC docs/rfc/implemented/feature/2026-07-14-cross-family-fs-sandbox.md; the old
sandbox RFC's In-process/deferred/FAQ sections updated to shipped fact.
kingwl