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/storage/filesystem.js

@@ -24,14 +24,14 @@ exports = module.exports = {
     removeDir,
 };
 
-const assert = require('assert'),
+const assert = require('node:assert'),
     BoxError = require('../boxerror.js'),
     constants = require('../constants.js'),
     debug = require('debug')('box:storage/filesystem'),
     df = require('../df.js'),
-    fs = require('fs'),
+    fs = require('node:fs'),
     mounts = require('../mounts.js'),
-    path = require('path'),
+    path = require('node:path'),
     paths = require('../paths.js'),
     safe = require('safetydance'),
     shell = require('../shell.js')('filesystem'),