Retarget the feature branch to the current master tip without rewriting its existing review history. Keeping this as a dedicated merge checkpoint makes the later simplification diff attributable to the stacked child rather than mixing base movement with design changes.
Resolve the identified-message API drift in the feature tests by constructing complete user messages, reading the nested tool-result message shape, and adapting the prompt-submit listener signature. Preserve both sides of the user-approval conflict: master’s createUserMessage wrapper and the feature’s inherited-policy attribution.
Regenerate the Cordis and persistence catalogs, re-record the session README pair, and refresh the affected ACP/headless fixtures so derived artifacts describe the merged source rather than either parent in isolation.
Validated with the focused policy/session/persistence/query suites (430 tests), focused ACP/headless snapshots (3 tests), build, doc-sync (25 gates), lint, hygiene, and git diff checks.
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.
