[zyzhou5]

Keep the logical rollout ID and attempt index independent from the attempt-qualified capture key so checkpoint participants can fence retries without depending on capture configuration. Expose the authoritative model call ID on captured responses for later boundary reconciliation.

(cherry picked from commit cd3de54)

Retarget the PR NVIDIA-NeMo#2939 identity change onto current main. Preserve main's training-only capture failure handling when adding the model-call ID header.

What does this PR do?

Validation

Rollouts

Compatibility and benchmark impact

Checklist

• I have read the contributing guidelines.
• The change is focused; unrelated "drive-by" edits are tracked as separate issues/PRs.
• Tests added or updated and pass locally, or N/A for docs-only / non-code changes (so CI unit/server checks pass when applicable).
• Documentation added or updated, or N/A with justification.
• Pre-commit checks pass locally (pre-commit run --all-files) (so CI lint/format checks pass).
• New source files include the required Apache-2.0 SPDX header.
• All commits have DCO sign-off (git commit -s) (so the DCO check passes).

[github-actions]

This PR is stale because it has been open for 14 days with no activity. Remove stale label or comment or update or this will be closed in 7 days.