test: smoke-test fixture for pipeline verification

[nabeelio]

Summary

• Adds disposable packages/phpvms/smoke-test.yml pointing at nabeelio/phpvms-registry-smoke-test v0.1.0.
• Exercises validator + release-block bot + publish pipeline end-to-end (section 12 of the bootstrap-addon-registry openspec change).
• Will be removed in a follow-up PR once the smoke test completes.

Test plan

1. validate-pr workflow runs against this PR; expect PASS comment with proposed release: block.
2. Merge; release-block-pr workflow opens bot PR appending the resolved release: block.
3. publish workflow uploads raw/packages.json + raw/keywords.json to R2.
4. Mark revoked: true in a follow-up PR; verify discovery skips upstream checks.
5. Remove the entry; verify index rebuilds without it.

[phpvms-registry-bot]

Registry validation: passed

[PASS] packages/phpvms/smoke-test.yml

Proposed release: block (the post-merge bot will append this):

release:
  version: "0.1.0"
  tag: "v0.1.0"
  zip_url: "https://github.com/nabeelio/phpvms-registry-smoke-test/releases/downl\
    oad/v0.1.0/smoke-test-addon-0.1.0.zip"
  sha256: "7d9dbb362b933534f49ffb654ce63c9f07824d78de4945d4c142e78e6a8786e7"
  published_at: "2026-05-05T01:25:53Z"