Automate Rust plugin release tags

[lucarlig]

Closes #82

Summary

• add a post-CI tag creation job for Rust Python package plugin version bumps merged to main
• require build, security, coverage, and documentation jobs to pass before tags are pushed
• call the reusable release workflow after tag creation with PyPI publishing enabled, avoiding reliance on bot tag-push recursion
• cover the workflow gate in catalog tests and make the canonical release-tag test follow the current Cargo version
• update release/testing docs for the automated tag and publish path