feat(cmdproof): serialize proof fallback by action key

[tomdps]

Summary

• release the cmdproof action-key single-flight fix on top of current main
• prevents concurrent validators from launching duplicate raw fallback CI for the same cmdproof action key
• keeps fallback behavior unchanged when verify output has no action key

Why this PR uses tomdps:dev

The normal upstream dev -> main PR (#525) is conflicted because dev lost the main ancestry edge when the merge queue squashed the no-file sync PR. The repo guard allows main PRs only from a branch named dev; this fork branch is named dev and is based directly on current main, so the release diff is clean and limited to the intended two files.

Validation

• feat(cmdproof): serialize proof fallback by action key #524 feature PR CI passed
• feat(cmdproof): serialize proof fallback by action key #524 merge-group CI passed into upstream dev
• This PR should run the required main CI/install matrix on the clean main-based patch

[github-actions]

🎉 This PR is included in version 6.2.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀