release: prepare base-bash-libs 2.2.1 #571

Goal

Prepare the first patch release after v2.2.0 so the immutable release documentation and onboarding contract are current and consistent.

Included work

• Carry the merged documentation repair from docs: make v2.2.0 the single current-release source of truth #567 into the v2.2.1 release.
• Advance VERSION, embedded release metadata, the README release row, and the dated changelog section to 2.2.1.
• Keep the v2.2.1 release notes explicit that this is a documentation and release-contract patch; no public API or runtime behavior changes are intended.
• Build and verify the canonical archive, checksum manifest, SPDX SBOM, and provenance assets from the final merged commit.

Acceptance criteria

• The repository-owned release guard accepts 2.2.1.
• VERSION, release metadata, README release row, changelog, and current-release documentation agree on 2.2.1.
• The release candidate passes ./tests/validate.sh, artifact rehearsal, and git diff --check.
• The final merged commit is used for the artifact and annotated tag; no existing tag or asset is rewritten.
• Remote release verification confirms all four canonical assets and their checksums/provenance.
• The Base and Homebrew downstream handoff issues are updated to target v2.2.1.

Related

• Documentation repair: docs: make v2.2.0 the single current-release source of truth #567
• Base handoff: release: adopt base-bash-libs v2.2.2 for Base 1.10.0 base#2482
• Homebrew handoff: formula: update base-bash-libs to v2.2.2 homebrew-base#88
• Consumer release: docs: make the external-consumer path executable from a fresh project base-bash-libs-demo#63