Use fully featured Kolibri/Hashi enhanced HTML5 app rendering to give veridical preview experience

Observed behavior

I can't use localStorage in my HTML5 app.

Expected behavior

Can use localStorage

User-facing consequences

My learning game need localStorage to work.

Errors and logs

Uncaught DOMException: Failed to read the 'localStorage' property from 'Window': The document is sandboxed and lacks the 'allow-same-origin' flag.

Steps to reproduce

I use this code in a simple javascript file :

    console.log(window.localStorage)

    if (window.localStorage) {
        window.localStorage.setItem('userId', 10)
        console.log(window.localStorage.getItem('userId'))
    }

Context

• Browser : Chrome
• Kolibri version : I use Kolibri Studio here : https://studio.learningequality.org/channels/

Start by reproducing the simple JavaScript example in Chrome and confirm the sandboxed document's localStorage error. Then trace how Kolibri Studio renders HTML5 apps and how its sandbox is configured; done means the learning game can use localStorage in preview while the intended isolation remains intact.