Update Stack CLI to 0.5.4

[konojunya]

Background

Stack CLI 0.5.4 is published as an immutable stable GitHub Release with all four target archives and verification material. The official tap still installs 0.5.3.

Implementation Approach

• Regenerate the formula from the 0.5.4 release manifest and checksum inventory.
• Pin all four target archive SHA-256 digests and the exact CLI source commit.
• Preserve the existing host support and lifecycle behavior.

Testing Approach

• scripts/update-stack-formula.sh 0.5.4
• scripts/test-formula-source.sh
• git diff --check
• GitHub Actions source verification and supported-host lifecycle matrix

Review Perspectives / Points of Concern

• The updater verified the release manifest, checksums, provenance, and SBOM attestations before writing either tracked file.
• No release artifact is replaced or repackaged.