Function needs_interstitial 

fn needs_interstitial(redirect_url: &Url, native: bool) -> bool

Whether the auth code is handed back via a “Continue” interstitial (a user gesture) rather than a direct redirect. True for private-use reverse-DNS app schemes (RFC 8252, e.g. io.element.android), which Chrome will not auto-follow, and for a native client’s https universal link, which iOS opens into the app only on a user navigation, not a silent 3xx. Web https and native http loopback redirect directly; a javascript: or data: target is neither dotted nor https, so it stays an inert Location, never a clickable link.