use node: prefix for requires

mostly because code is being autogenerated by all the AI stuff using
this prefix. it's also used in the stack trace.

src/settings.js

@@ -44,7 +44,7 @@ exports = module.exports = {
     _set: set
 };
 
-const assert = require('assert'),
+const assert = require('node:assert'),
     database = require('./database.js'),
     safe = require('safetydance');