Fix main CI version tagging

[abewheel]

Summary

• Read the bumped package version from package.json instead of parsing pnpm version output
• Quote the generated tag ref when creating and pushing it

Testing

• Confirmed the version command writes a bare semver to package.json in a temp package
• Full validate was started and passed format, lint, build, typecheck, unit tests, package e2e, docs validation, and example generation before being stopped during generated-project validation