Pie-tu

Add platform option to enable mac use

1

Add platform option to `update.sh`. This allows downloading the latest Chromium version for mac OS too. Examples: ``` ./update.sh mac ./update.sh linux ./update.sh # defaults to linux ```

[bug] Iframe is not able to receive invoke callbacks

4

### Describe the bug I am mounting an iframe ("child") within a Tauri app. I control both the parent and child and they both are rendered via tauri's vite build....