Replace the centered avatar/name toolbar title with the
About/Videos/Shorts/Streams/Playlists segmented picker. The channel
avatar and name move to the leading edge next to the view options
button, in their own glass capsule (sharedBackgroundVisibility(.hidden)
+ glassEffect on macOS 26). Add spacing between the channel banner and
the content below now that the inline picker is gone.
aa81fdac7d