Fix IOS opening in safari on wrapped proxy errors

[reinabo]

Fixes IOS app opening the page in Safari when switching from wrapped proxy -> rails.

The bug:

1. We call throw redirect(resp.url) which contains the entire URL with base domain
2. Vike sees the url doesn't start with / so decides to call window.location.href=resp.url
3. Turbolinks IOS decides that this must be opened externally which it does for all window.location.href = {absolute URL} calls and passes this info to AlignableApp
4. AlignableApp decides to open in safari when turbolinks passes openExternalURL .

The fix:

Convert window.location.href={absolute url} to window.location.href={relative url} when redirecting to the same domain.

Why no tests?

I couldn't find a way to mock the window.location.href setter with playwright. Most things I have tried results in Uncaught TypeError: Cannot redefine property: location.