migrate to "export default"

also, set no-use-before-define in linter

src/scripts/backupupload.js

@@ -7,8 +7,8 @@ if (process.argv[2] === '--check') {
     process.exit(0);
 }
 
-const backuptask = await import('../backuptask.js');
-const database = await import('../database.js');
+const { default: backuptask } = await import('../backuptask.js');
+const { default: database } = await import('../database.js');
 const { default: debugModule } = await import('debug');
 const { default: safe } = await import('safetydance');