Upgrade to Node.js 25.5.0 (#496)

* upgrade to node 25.5.0

* fix: use node: prefix for readline/promises (Deno compat)

* fix: add node: prefix to all bare built-in imports (Deno compat)

* revert: remove node: prefix changes (use --unstable-node-builtins instead)

* Add --unstable-node-globals flag to Deno plugin runner

* Revert --unstable-node-globals from Deno plugin runner