v2.0.0: migrate build and publish scoped ESM package

- Rename the package to @stefanobalocco/scryptserver
- Add ESM exports, CLI metadata, Node.js engine requirements
- Migrate the build to @stefanobalocco/tsbuild
- Upgrade runtime dependencies and migrate to @stefanobalocco/zeptologger
- Restore legacy v1 hash comparison with full historical parameter validation
- Expand client, server lifecycle, and legacy hash coverage
- Add c8 coverage reporting and standalone test compilation