feat: initialize voice-mobile React Native app with NativeWind v5

- Created new Expo app with SDK 54+ and Expo Router
- Installed and configured NativeWind v5 for Tailwind styling
- Upgraded voice-assistant to React 19 for consistency
- Kept voice-mobile outside workspace to avoid Metro bundler conflicts
- Disabled React Compiler experimental feature for stability

Setup includes:
- postcss.config.mjs with Tailwind PostCSS plugin
- global.css with Tailwind and NativeWind imports
- metro.config.js with NativeWind wrapper
- lightningcss pinned to 1.30.1 for stability

Generated with [Claude Code](https://claude.ai/code)
via [Happy](https://happy.engineering)

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Happy <yesreply@happy.engineering>

packages/voice-mobile/components/ui/collapsible.tsx

@@ -0,0 +1,45 @@
+import { PropsWithChildren, useState } from 'react';
+import { StyleSheet, TouchableOpacity } from 'react-native';
+
+import { ThemedText } from '@/components/themed-text';
+import { ThemedView } from '@/components/themed-view';
+import { IconSymbol } from '@/components/ui/icon-symbol';
+import { Colors } from '@/constants/theme';
+import { useColorScheme } from '@/hooks/use-color-scheme';
+
+export function Collapsible({ children, title }: PropsWithChildren & { title: string }) {
+  const [isOpen, setIsOpen] = useState(false);
+  const theme = useColorScheme() ?? 'light';
+
+  return (
+    <ThemedView>
+      <TouchableOpacity
+        style={styles.heading}
+        onPress={() => setIsOpen((value) => !value)}
+        activeOpacity={0.8}>
+        <IconSymbol
+          name="chevron.right"
+          size={18}
+          weight="medium"
+          color={theme === 'light' ? Colors.light.icon : Colors.dark.icon}
+          style={{ transform: [{ rotate: isOpen ? '90deg' : '0deg' }] }}
+        />
+
+        <ThemedText type="defaultSemiBold">{title}</ThemedText>
+      </TouchableOpacity>
+      {isOpen && <ThemedView style={styles.content}>{children}</ThemedView>}
+    </ThemedView>
+  );
+}
+
+const styles = StyleSheet.create({
+  heading: {
+    flexDirection: 'row',
+    alignItems: 'center',
+    gap: 6,
+  },
+  content: {
+    marginTop: 6,
+    marginLeft: 24,
+  },
+});