Sheet dismiss buttons rendered as an iOS-style circular glass "X" on
macOS 26, which looks foreign on the desktop. Add a shared
sheetCloseToolbarItem helper that renders a native text "Close" button
on macOS while keeping the compact icon-only xmark on iOS/tvOS, and
replace the ~14 duplicated inline close buttons across sheets with it.
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.
