Summary
- Gate registry indexing on final manifest verification, both macOS download smoke tests, and verified SBOM attachment.
- Keep registry networking best-effort without masking failures in the preceding release gates.
- Add semantic workflow regressions and reject metadata-only or empty CycloneDX/SPDX inventories.
- Validate required SBOM documents before artifact upload instead of printing errors and continuing.
Verification
- Rebased onto main after #294, #297, #299 and #300 merged; the two remaining commits are patch-equivalent to the previously green branch.
- 14 release/SBOM/scanner regression tests pass (92 assertions), with Pickier, actionlint and diff checks passing.
- Fresh CI is required for the rebased head.
The prerequisites are now on main. No release is published by this PR.