fix(js): keep test/helpers.js free of src imports

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>

js/test/m09-app.test.js

@@ -6,7 +6,8 @@ import { trace } from '../src/io.js'
 import { view } from '../src/view.js'
 import { newGame } from '../src/spawn.js'
 import { Action } from '../src/model.js'
-import { freeze, classicMain } from './helpers.js'
+import { freeze } from './helpers.js'
+import { classicMain } from './m09-helpers.js'
 
 const time = (t) => ({ tag: 'Time', t })
 const down = (key) => ({ tag: 'KeyDown', key })