Upgrade GoReleaser to v2 and add automated release workflow

[corylanou]

This PR upgrades our release tooling to GoReleaser v2 and adds automation for future releases.

Changes:

• Upgrade GoReleaser configuration to v2: Updated .goreleaser.yaml from version 1 to 2
• Fix deprecation warnings: Replaced deprecated format with formats (plural) in archives configuration
• Add automated release workflow: New .github/workflows/release.yml that automatically triggers releases when tags are pushed
• Comprehensive release documentation: Added RELEASE.md with detailed instructions for both manual and automated releases

Benefits:

• 🚀 Automated releases: Future releases will be fully automated via GitHub Actions
• 🔧 Up-to-date tooling: Using latest GoReleaser v2 with no deprecation warnings
• 📚 Better documentation: Clear step-by-step release process for maintainers
• ⚡ Simplified workflow: Push a tag → automatic release with binaries for all platforms

Workflow:

Current (manual): git tag v0.3.2 && git push origin v0.3.2 && goreleaser release --clean
Future (automated): git tag v0.3.3 && git push origin v0.3.3 (GitHub Actions handles the rest)

The release workflow builds binaries for Linux, Windows, and macOS, generates changelogs, and publishes everything to GitHub Releases automatically.