chore: prepare v0.6.0 release metadata

[Helweg]

Summary

• bump the package version to 0.6.0 in package.json and package-lock.json
• add the 0.6.0 changelog entry and roll the compare links forward for the next unreleased cycle
• prepare the repository for release publication after the metadata-only PR merges

Verification

• npm run typecheck
• npm run lint
• npm run test:run
• npm run build
• cargo fmt --check
• cargo clippy -- -D warnings
• cargo test