feat(e9): publish signed beta prereleases

[gnanirahulnutakki]

Summary

• accept only canonical vMAJOR.MINOR.PATCH and vMAJOR.MINOR.PATCH-beta.N signed release tags
• publish beta tags as prereleases with make_latest explicitly sent as the API string enum false
• cover the policy in the normal CI shell suite and document the immutable beta procedure

Validation

• make ci
• make release-check
• KIND=/Volumes/EXTENDED/MacData/tools/bin/kind make e2e-kind
• manual red-team review: classifier boundary, preserved signed/annotated/main ancestry gates, and API field types
• security queues: Dependabot 0, code scanning 0, secret scanning 0

Review note

CodeRabbit reached analysis but returned no verdict within its bounded attempt; the repository reports reviews are disabled for the dev base branch. This is not treated as approval.

Closes #154
Refs #27

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on base/target branches other than the default branch.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: c38c416d-d1c5-4dcb-b457-9c2695a3aa35

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch gnanirahulnutakki/feat/e9-beta-prerelease

---

_{Comment @coderabbitai help to get the list of available commands.}