ci: make release test coverage explicit

[rogerchappel]

Summary

• Make test-suite coverage explicit on the release:check path by invoking npm run test directly.
• Keep build, smoke, and package smoke checks; the release path no longer repeats tests via npm run check.

Verification

• Tests or checks run: npm ci; npm run release:check (23 tests passed, build syntax check passed, smoke passed, package dry-run passed); git diff --check.
• Manual review completed: confirmed CI chooses release:check when defined and retains its fallback npm test --if-present.

Risk Level

• Low

Notes: No workflow trigger or publication behavior changed. Push/PR triggers run verification only.

Rollback Plan

• Revert commit 5353f0e.

Human Decision Needed

• Maintainer review