Pnpm 12.0

Pnpm 12.0, a complete rewrite in Rust, has been released as a stable version while maintaining backward compatibility with pnpm 11's commands, flags, and lockfile format. Key improvements include changes to how git dependencies are resolved (now using canonical HTTPS URLs), stricter validation of workspace settings with error reporting, and optimized lockfile generation for cyclic dependencies that is 2-3× faster and produces smaller, byte-identical lockfiles. The update can be installed via the next-12 tag and existing lockfiles remain compatible.