Consolidation: overlap receipt for the fourth100 witness-MANIFEST pin family (#636/#638/#639/#640/#642/#644/#646) — one drifted larger_gain pin, partial retention, credit intact (no new kappa) - #1665

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4, actions/setup-python@v5, actions/upload-artifact@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/