[LunaStev]

Running Publish HMath release before a separate preparation failed at candidate selection. Make the publish workflow prepare and verify its own candidate automatically, then publish that same candidate in one workflow run.

• Remove the Prepared run ID input. Keep the existing package-index choice and PyPI trusted-publisher workflow filename.
• Call the existing reusable preparation workflow when no staged release exists; publication depends on successful preparation.
• Reuse an existing staged release's original artifacts after validating repository, source commit, version and successful candidate verification. Re-running failed jobs retains the successful preparation and its artifacts.
• Retain the existing artifact/hash checks and Hackage, PyPI and GitHub publication steps.

Only two files under .github/workflows/ change. Library sources, tools, tests, README, documentation and version metadata are unchanged. This PR does not merge or publish a release.

Validation: actionlint passes for both workflows; eight isolated workflow-selector and gating scenarios pass (first run, recovery, incomplete preparation, wrong provenance/version, API failure and legacy preparation); all 28 existing candidate/publication tests pass. No external publication was executed during verification.