Plain-Form sheets rendered as columns-style content floating inside
oversized fixed frames on macOS. Anchor these panels to their toolbar
buttons as popovers instead, sized to content; iOS/tvOS keep sheets.
- Search and PeerTube explore filters apply live (Cancel never
reverted anything anyway) and dismiss on outside click
- Subscriptions/Manage Channels "Subscriptions Data" opens as a sheet
from the popover's onDisappear via a pending flag, since presenting
while the popover dismisses gets swallowed
- Media browser view options drop navigation chrome on macOS
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.
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.