Windows caption buttons take the bar's height less its hairline, a new
token, instead of their row's, so they keep their height beside caps
that wrap below them. A title bar's title is an Ellipsis: on Windows it
takes the free width before the buttons and gives way; a centered title
sits inset past the lights on both sides. The controls never shrink.
Tests hold a long Windows title's close button inside a 280px bar and
wrapped caps inside their row.
theme::Platform moves out of typography and shell's ControlsStyle folds
into it; the theme's platform starts as the system's. Window buttons Ely
draws, the title bar's layout and every key cap follow it, secondary
included, through typography::keys::keystroke; a title bar whose buttons
the OS draws follows the OS. primitives::IconTheme lays an owner's rules
by file name and extension over Ely's map, for every file icon.
shell::Vibrancy fills a pane with the palette's new glass, translucent
so a window opened Blurred shows its backdrop, solid under high contrast.
gpui 0.2.2 has no Mica; that line stays blocked.