Delete declarations that Periphery reports unused on every platform that
compiles them (iOS, macOS, tvOS), including nine views used only by their
own previews. Platform-gated code still used on another platform, device-
only MPV render paths, migration models, CloudKit record names, App
Intents metadata and unused parameters are kept.
A toast shown while a shared sheet was up, such as a failed link action
over Open Link, appeared behind the sheet. Sheets from .appSheetHost now
carry their own toast overlay, and only the top-most overlay of a scope
shows its toasts.
Toast cards now follow the finger upward and dismiss on either a
sufficient drag or a fast flick (via predicted-end translation). The
auto-dismiss timer pauses while the user is dragging and re-arms if
they release without dismissing.
