Connect Apple Music and Spotify-via-Last.fm on iPhone

- Local Expo module (Swift): MusicKit authorization, Music User Token via
  MusicUserTokenProvider, and live Music app now-playing while the app is
  open (MediaPlayer notifications), reported through the device endpoint
- One-tap Apple Music onboarding on iOS; Apple Music row in Settings
- Sign in with Last.fm, plus a guided Spotify-via-Last.fm flow when direct
  Spotify sign-in is capped
- Device registration moved to shared code used by Android and iOS
Not yet compiled for iOS (no Xcode here); needs an EAS build.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MzFywujuH9TiuXbr9vjoX8

apps/mobile/modules/apple-music/ios/AppleMusic.podspec

@@ -0,0 +1,24 @@
+Pod::Spec.new do |s|
+  s.name           = 'AppleMusic'
+  s.version        = '1.0.0'
+  s.summary        = 'Apple Music authorization, user token and Music app now-playing'
+  s.description    = 'Local Expo module for musicshare'
+  s.author         = ''
+  s.homepage       = 'https://docs.expo.dev/modules/'
+  s.platforms      = {
+    :ios => '16.4',
+    :tvos => '16.4'
+  }
+  s.source         = { git: '' }
+  s.static_framework = true
+
+  s.dependency 'ExpoModulesCore'
+  s.frameworks = 'MusicKit', 'MediaPlayer'
+
+  # Swift/Objective-C compatibility
+  s.pod_target_xcconfig = {
+    'DEFINES_MODULE' => 'YES',
+  }
+
+  s.source_files = "**/*.{h,m,mm,swift,hpp,cpp}"
+end