Buttons in the section, mini player, and pill editors can now be
removed via long-press/right-click context menu instead of only
swipe-to-delete. This also gives macOS a delete affordance in the
section editor, which previously had none.
Rename the macOS "Control Bar Buttons" settings entry to "Control Bar"
and add an Auto/Light/Dark glass background picker on that page. The
choice is stored per-preset as GlobalLayoutSettings.controlBarTheme and
forces the bar's glass color scheme via glassBackground(colorScheme:).
Render the macOS control bar button row and top bar from the active
preset's sections via a new MacOSControlsSectionRenderer, replacing the
hardcoded QuickTime-style rows in MacOSControlBar. Add a keepOnTop
button type and macOS-specific button availability lists, and adapt the
player controls settings editors (preset editor, section editor, button
configuration) for macOS.
Also apply the preset font style to the control bar time labels, and
update the built-in macOS Default preset order (queue before transport,
fullscreen at the end), bumping builtInPresetsVersion to 7.
