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/routes/filemanager.js

@@ -4,9 +4,9 @@ exports = module.exports = {
     proxy,
 };
 
-const assert = require('assert'),
+const assert = require('node:assert'),
     BoxError = require('../boxerror.js'),
-    http = require('http'),
+    http = require('node:http'),
     HttpError = require('@cloudron/connect-lastmile').HttpError,
     safe = require('safetydance'),
     services = require('../services.js');