External URL declarations

Additional URL schemes

Root url_schemes = ["feed", "web+feed"] registers external protocol candidates alongside the app’s navigation scheme. Names use lowercase URI scheme syntax ([a-z][a-z0-9+.-]*). Install day::on_open_url in the root to consume original URLs before routing; see external URL handling. PWA protocol handlers support only browser-permitted web+ names. Scheme registration and MIME file associations do not force browser handoff or change a user’s default handler.