UiButton gains pressedClass, Core's class on a pressed button. The pressed
classes toggle through classList, so classes other code adds survive a
press, a caller's class change keeps them, a renamed pressedClass leaves
the button, and server-rendered markup carries them.
The Display, SDR, Radio and Cockpit enable, Cockpit weather and briefing,
mission replay, Street Level, TR-3B, overlay, voice and CCTV toggles now
render through it with the same ids, classes and aria-pressed values.
PanelChrome no longer writes the panels' collapse buttons, the command
dock tray toggles' names or the dock pins' pressed state. It presents each
panel's open and pinned state to the new gev-panel-chrome store, and the
buttons, now views, call it there: PanelCollapseButton for the panel
headers, bound toggles and pins in the command dock. Clicks take effect
once the chrome is initialized; a new owner starts from its own states.
bindPanelDisclosure binds only a panel's Escape and refuses the retired
buttons and onChange arguments. UiButton joins the component kit.