v3.8.0

Added

• add release.sh to automate release flow and simplify changelog.sh
• skip metadata.json version bump when src/ has no changes between tags

Fixed

• unquote glob in local.sh so rm clears extension folder correctly
• use CommonJS require in ci metadata validation node script

Changed

• extract maintainer release process to RELEASING.md
• restructure CONTRIBUTING with contributor-first layout, maintainer section at the end
• mark release section as maintainer-only and expand contributor workflow
• remove unused source_folder variable from local.sh
• fix scenario B description, expand commit table, fix local.sh path
• update changelog.sh and CONTRIBUTING with full release step sequence
• fix release order — push tag after CHANGELOG is on main