Mobile: remove floating MusicToggle overlay (overlapped cards/tiles)

The fixed-position music button covered content on mobile. Removed it from
the global overlay; mute now lives in the TopBar icon group (Home), and the
in-game HUD + Profile settings already have their own audio controls.
Tightened the TopBar icon row (p-1.5, gap-1, profile max-w-44%) so the extra
button still fits 360px phones.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/page.tsx

@@ -20,7 +20,6 @@ import { DailyRewardModal } from "@/components/online/DailyRewardModal";
 import { NotificationToaster } from "@/components/online/NotificationToaster";
 import { ResumeGameBar } from "@/components/online/ResumeGameBar";
 import { CelebrationOverlay } from "@/components/online/CelebrationOverlay";
-import { MusicToggle } from "@/components/online/MusicToggle";
 import { ErrorBoundary } from "@/components/ErrorBoundary";
 import { PublicProfileModal } from "@/components/online/PublicProfileModal";
 import { CapacitorBack } from "@/components/CapacitorBack";
@@ -202,7 +201,6 @@ export default function Page() {
         <NotificationToaster />
         <ResumeGameBar />
         <CelebrationOverlay />
-        <MusicToggle />
         <PublicProfileModal />
       </ErrorBoundary>
       <CapacitorBack />