feat(panels): render collapse, dock and pin buttons from the store

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.

CHANGELOG.md

@@ -100,6 +100,14 @@
   panel: ESC still stops a playing scene and the runtime chip still shows
   (samehkhamis).
 
+- The shell's panel chrome no longer writes the panels' collapse buttons,
+  the dock tray toggles' names or the dock pins' pressed state: it presents
+  each panel's open and pinned state to the `gev-panel-chrome` store, and
+  the buttons, now views, call it there. `bindPanelDisclosure`
+  (`./ui/panels`) binds only a panel's Escape; it no longer takes `buttons`
+  or `onChange`. `UiButton` joins the component kit with ui-vue's props
+  (samehkhamis).
+
 ## [0.3.0] — 2026-10-27 — Street Level, On Your Phone, in Your Language
 
 - Show a Street Level view facing 359.5° or more as 0°. The viewer caption