The toolbar Cancel is iOS/macOS only, so while scanning with no shares
found yet (and when discovery is unavailable) the tvOS sheet had nothing
the remote could focus.
Drop nested NavigationStack, .searchable, and close button from the
PeerTube explore view on tvOS; use an inline search field plus Filters
button so focus separates cleanly and the sidebar title is no longer
overlapped. Keep the header visible across empty/error states so the
query can be cleared. Hide the filters and scan-network sheet toolbars
on tvOS, apply filter changes immediately, and add padding plus
scrollClipDisabled so focused rows aren't clipped.
On tvOS, ContentUnavailableView inside a Group doesn't expand to fill
available space — it sizes to content and aligns top-leading. Add
.frame(maxWidth: .infinity, maxHeight: .infinity) to all instances
so they center correctly in their parent containers.
