ci: fix Release workflow (Node 22) + add missing changeset

[chiliec]

Problem

The Release workflow has been failing on every push to main, so merged changes never publish to npm. Root cause in the run logs:

npm error code EBADENGINE
npm error notsup Required: {"node":"^22.22.2 || ^24.15.0 || >=26.0.0"}
npm error notsup Actual:   {"npm":"10.8.2","node":"v20.20.2"}

The job runs npm install -g npm@latest (for OIDC Trusted Publisher support) but pins Node 20. npm@latest is now v12, which requires Node ≥22 → the step exits 1 before build/publish.

Fix

1. Bump the Release job to Node 22 so npm@latest installs cleanly and the OIDC --provenance publish path works. (CI workflow is unaffected — it does not upgrade npm; its 18/20/22 matrix stays.)
2. Add the changeset that was missing when the witness→validator read-type fix merged, so Changesets bumps the package and actually cuts the release.

Result

On merge, Changesets opens/lands the version bump and the OIDC publish step ships the patch to npm — no NPM_TOKEN needed (Trusted Publisher).