Play the platform music on the shared Learn page too

Reversing yesterday's call at Karti's direction. The provider moves from Shell
up above the router in App, so a share-code visitor gets the same character as
a member rather than a silent page.

The reason that is safe is the same reason "autoplay" was never really
autoplay: the browser refuses audio until the page has had a real gesture, so
nothing plays the instant a link opens — it starts once someone is actually
using the page.

The anonymous page renders OUTSIDE Shell and therefore has no app header, so
the mute control is added to its own chrome. Music with no way to stop it is
the worst version of this feature, and a visitor who cannot find the switch
does not conclude the site has taste.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

apps/web/src/components/Shell.tsx

@@ -29,7 +29,6 @@ import { NavLink } from 'react-router-dom';
 import { useIdentity } from '@/lib/identity';
 import { useLayout } from '@/lib/layout';
 import { visibleNav, type NavItem } from '@/lib/nav';
-import { PlatformAudioProvider } from '@/lib/audio';
 import { AppHeader } from './AppHeader';
 import { AppSidebar } from './AppSidebar';
 import { PiggyDock } from './PiggyDock';
@@ -45,14 +44,6 @@ export function Shell() {
   const items = visibleNav(identity);
 
   return (
-    /*
-     * Music is mounted HERE rather than in App.tsx, so it wraps only the
-     * signed-in application. The anonymous Learn page renders outside Shell,
-     * and a share-code visitor opening a link someone sent them should not get
-     * unexpected audio — that is the one context where it reads as a fault
-     * rather than as character.
-     */
-    <PlatformAudioProvider>
     <SidebarProvider
       open={sidebarOpen}
       onOpenChange={setSidebarOpen}
@@ -98,7 +89,6 @@ export function Shell() {
 
       <MobileTabBar items={items.filter((item) => item.primary)} />
     </SidebarProvider>
-    </PlatformAudioProvider>
   );
 }