Mirror strict Clay publication gate

[jamiepratt]

Review status

CAUTION: This is an AI-generated CI/publication-policy change. It requires independent review and approval by someone other than the author. Do not merge without that approval.

Summary

Mirror the proposed strict Civitas publication gate on this fork:

• Java 21 with a production-like 1 MiB stack
• reject Clay FAILED markers and emit GitHub error annotations
• retain the historical StackOverflowError regression test
• run the full Clay plus Quarto build on pull requests
• prevent any Pages deployment from this fork

Separation

The Beta article overflow repair was separated and merged in #4. This PR contains only five strict-gate workflow, script, test, and documentation files; no article or extracted resource changes.

Validation

• bash syntax and shellcheck passed
• regression fixture rejects the previous StackOverflowError behavior
• identical gate scripts passed strict Clay and Quarto 233/233 on the repaired upstream base

Generated by AI. Human review required.

[jamiepratt]

Branch rewritten after separation: 2382430 is the complete gate-only fork change. Earlier combined commit SHAs and comments referring to article/resource extraction are superseded; the fork repair is already merged separately as #4. This PR must remain unmerged until independently reviewed and approved.

[jamiepratt]

Gate-only fork verification complete: GitHub Actions run 29419273670 passed the build on 2382430, including the historical failure-detection regression, full strict Clay render, and full Quarto render. The deploy job was skipped as required for this fork pull request. This is verification, not approval; independent human review is still required before merge.