Automatically release on changing package.json version

[eugene-kim-pipe17]

Summary

This PR automates the release process to trigger whenever a PR is merged into main with a new version number in server/package.json.

Changes

• .github/workflows/release.yml:

  • Changed trigger from manual tags to push on main.
  • Added a check-version job to detect if the version in package.json is new (i.e., does not have a corresponding git tag).
  • Added a test job that runs only when a new version is detected.
  • Updated release job to automatically create the git tag and publish to NPM/Docker using the detected version.
  • Fixed prerelease detection to check the version string (e.g., 1.0.0-beta) instead of the git branch.

• CONTRIBUTING.md:

  • Updated the "Release Workflow" section to document the new automated process.
  • Added guidelines on when to bump the version (bug fixes/features) vs. when not to (docs/tests).

How it Works

1. Update Version: Bump version in server/package.json in your PR.
2. Merge: Merge the PR into main.
3. Auto-Release: The workflow detects the new version, tests it, tags it, and publishes it automatically.