Add macOS-only minimum frame sizing to sheets that wrap a
NavigationStack/Form without intrinsic size, so they render properly
instead of collapsing to just the toolbar. Affects Customize Home,
subscription/channel view options, playlist create/edit, search
filters, media browser options, instance picker, log filters, preset
editor, and legacy data import result.
Form inside a sheet causes clipped rows and invisible text on focused
items due to white-on-white rendering. Use a plain List on tvOS which
handles the focus styling correctly.
The .pickerStyle(.menu) hid labels. Instead, wrap the Form in a
NavigationStack on tvOS so the default navigation picker style works
and shows both labels and values.
