Use node:-prefixed imports for Node.js core modules

[olriko]

Currently, the package uses bare specifiers to import Node.js core modules. This prevents the package from being used in environments like Cloudflare Workers Runtime, which don't support Node.js APIs.

To improve compatibility, we should update our imports to use the node: prefix for all Node.js core modules.

Example change:

• import fs from 'fs';

• import fs from 'node:fs';

https://developers.cloudflare.com/workers/runtime-apis/nodejs/