[Brian Krabach (bkrabach)]

Keep a safely suspended child attached to the original delegate tool completion owner. An opt-in host capability recognizes its own proven suspension outcome; resume_execution validates the original parent/tool call, preserves the remaining timeout, invokes the host's exact child continuation, and runs the same completion/result-contract/budget-reporting path once. It never falls back to spawning a replacement child or replaying the delegate arguments.

Ordinary delegation, errors and cancellation retain their existing behavior when the host supplies no suspension capability. This is the Foundation component of coordinated host maintenance support with microsoft/amplifier-module-loop-streaming#67 and microsoft/amplifier-module-loop-live#16.

Validation: 76 existing delegate checks plus 6 focused suspension/identity/deadline/cancellation checks passed in isolation. Composed actual Core/Foundation application tests also retain a finite child's original completion across a worker/application restart and deliver its counted effect once. No live-provider or arbitrary remote cancellation guarantee is claimed.

Draft for coordinated public-contract review; no application release or live adoption is part of this PR.

[Brian Krabach (bkrabach)]

Independent source review at 5265d6c against base a5f91fc is clear within the Foundation scope. The opt-in continuation preserves parent/child/tool-call identity, remaining deadline, result contract, budget/routing attribution and the existing completion owner. It does not fall back to spawning or replaying the original tool input. Cancellation and completion-acknowledgement failure remain distinct from successful completion.

The six platform/Python CI jobs and CLA are green at this head; this review did not rerun tests. Durable once-only claims, current Stop/admission and recovery when completion was saved before an acknowledgement failed remain host-integration responsibilities, to be demonstrated by the coordinated Unified change. The hook-failure test establishes no internal retry, not that durable recovery already exists.

No actionable Foundation source finding. Normal eligible maintainer approval is still required; this comment is not a formal approval or authorization to bypass protection.