Mobile: redesign, onboarding, QR codes, logo, Spotify setup

- Redesign matching the web: album-art backdrops, Reanimated equalizer,
  spinning live ring, drifting ambient background, gradient buttons with
  spring press feedback and haptics, Space Grotesk headings, animated feed
  (enter + layout transitions); fix invisible tab labels
- Four-step onboarding for new accounts: which app you listen with (sets
  where songs open), the matching share setup, find friends (search,
  scan, invite), and a featured song. Skippable; stored server-side
- QR codes: My code (share link) and an in-app scanner (camera only, no
  microphone permission)
- Spotify setup via Last.fm or ListenBrainz with guided linking; Android
  shares Spotify automatically through the phone reader
- New logo as app icon, adaptive/monochrome icon and splash
- app.config.ts allows cleartext only for local http:// test builds

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

apps/mobile/src/components/AuthForm.tsx

@@ -1,3 +1,4 @@
+import { Image } from 'expo-image';
 import { Link } from 'expo-router';
 import { useState } from 'react';
 import { KeyboardAvoidingView, Platform, StyleSheet, View } from 'react-native';
@@ -32,7 +33,8 @@ export function AuthForm({ mode }: { mode: 'login' | 'register' }) {
       <Screen edges={mode === 'login' ? ['top'] : []} contentContainerStyle={styles.content}>
         {mode === 'login' && (
           <View style={{ gap: space.sm }}>
-            <Title style={{ fontSize: 34 }}>musicshare</Title>
+            <Image source={require('@/assets/images/icon.png')} style={styles.logo} />
+            <Title style={{ fontSize: 36 }}>musicshare</Title>
             <Body muted>See what your friends are playing, and open it in your own app.</Body>
           </View>
         )}
@@ -85,4 +87,5 @@ export function AuthForm({ mode }: { mode: 'login' | 'register' }) {
 const styles = StyleSheet.create({
   content: { flexGrow: 1, justifyContent: 'center' },
   link: { color: colors.muted, textAlign: 'center', paddingVertical: space.sm },
+  logo: { width: 76, height: 76, borderRadius: 20, marginBottom: space.sm },
 });