Answer the review: sky toggles in system view too, one media query, idempotent openSearch

Three findings from the automated review, all confirmed before acting.

The Sky toggle did nothing in system view. Its write lived only in the galaxy
crossfade, which the tick parks while the system group is up — and the sky is
still on screen there. It is now also written on toggle, in applyDisplay. The
suggested form of that fix crashed the scene on mount: the effect that calls
applyDisplay fires once at construction, before the engine has a scene, and
getScene() throws — the dock rendered no tabs at all. Guarded on
engine.isInitialized; verified with a screenshot of Proxima with the sky off.

isWideViewport built a fresh MediaQueryList on every document pointer-down;
one module-level query is read instead. And openSearch in the e2e support
clicked the Search tab unconditionally, which would fold it closed if a test
ever called it while already open; it now checks aria-selected first.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016jxMkwA2rbicdGxHosecYi

src/app/features/hud/hud-dock.component.ts

@@ -38,9 +38,11 @@ const TAB_LABELS: Record<DockTab, string> = { search: 'Search', readout: 'Readou
 
 /** Tailwind's `sm` breakpoint: below it the dock is a bare tab strip and its panel is a sheet. */
 const WIDE_VIEWPORT = '(min-width: 640px)';
+/** One live query, read on every pointer-down, rather than a new MediaQueryList per read. */
+const wideViewportQuery = typeof window !== 'undefined' && typeof window.matchMedia === 'function' ? window.matchMedia(WIDE_VIEWPORT) : null;
 
 function isWideViewport(): boolean {
-  return typeof window === 'undefined' || typeof window.matchMedia !== 'function' ? true : window.matchMedia(WIDE_VIEWPORT).matches;
+  return wideViewportQuery?.matches ?? true;
 }
 
 /**