feat(mobile): Implement persistent theme selection

MobileApp/app/(tabs)/settings.tsx

@@ -1,12 +1,15 @@
-import { StyleSheet } from 'react-native';
+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 { useTheme } from '@/context/ThemeContext';
 import { useColorScheme } from '@/hooks/use-color-scheme';
 
 export default function SettingsScreen() {
     const colorScheme = useColorScheme();
+    const { themeMode, setThemeMode } = useTheme();
     const theme = colorScheme ?? 'light';
 
     const cardStyle = [
@@ -25,21 +28,32 @@ export default function SettingsScreen() {
             </ThemedView>
 
             <ThemedView style={styles.sectionHeader}>
-                <ThemedText type="subtitle">Account</ThemedText>
+                <ThemedText type="subtitle">Appearance</ThemedText>
             </ThemedView>
             <ThemedView style={cardStyle} variant="card">
-                <ThemedText style={styles.item}>Profile</ThemedText>
+                <TouchableOpacity
-                <ThemedText style={styles.item}>Notifications</ThemedText>
+                    style={styles.item}
-                <ThemedText style={[styles.item, styles.lastItem]}>Privacy</ThemedText>
+                    onPress={() => setThemeMode('light')}
-            </ThemedView>
+                >
+                    <ThemedText>Light Mode</ThemedText>
+                    {themeMode === 'light' && <IconSymbol name="checkmark" size={20} color={Colors[theme].tint} />}
+                </TouchableOpacity>
 
-            <ThemedView style={styles.sectionHeader}>
+                <TouchableOpacity
-                <ThemedText type="subtitle">General</ThemedText>
+                    style={styles.item}
-            </ThemedView>
+                    onPress={() => setThemeMode('dark')}
-            <ThemedView style={cardStyle} variant="card">
+                >
-                <ThemedText style={styles.item}>About</ThemedText>
+                    <ThemedText>Dark Mode</ThemedText>
-                <ThemedText style={styles.item}>Help & Support</ThemedText>
+                    {themeMode === 'dark' && <IconSymbol name="checkmark" size={20} color={Colors[theme].tint} />}
-                <ThemedText style={[styles.item, styles.lastItem]}>Sign Out</ThemedText>
+                </TouchableOpacity>
+
+                <TouchableOpacity
+                    style={[styles.item, styles.lastItem]}
+                    onPress={() => setThemeMode('system')}
+                >
+                    <ThemedText>System Default</ThemedText>
+                    {themeMode === 'system' && <IconSymbol name="checkmark" size={20} color={Colors[theme].tint} />}
+                </TouchableOpacity>
             </ThemedView>
         </ThemedView>
     );
@@ -71,6 +85,9 @@ const styles = StyleSheet.create({
         padding: 16,
         borderBottomWidth: StyleSheet.hairlineWidth,
         borderBottomColor: 'rgba(0,0,0,0.05)',
+        flexDirection: 'row',
+        alignItems: 'center',
+        justifyContent: 'space-between',
     },
     lastItem: {
         borderBottomWidth: 0,

MobileApp/app/_layout.tsx

@@ -1,8 +1,9 @@
-import { DarkTheme, DefaultTheme, ThemeProvider } from '@react-navigation/native';
+import { DarkTheme, DefaultTheme, ThemeProvider as NavigationThemeProvider } from '@react-navigation/native';
 import { Stack } from 'expo-router';
 import { StatusBar } from 'expo-status-bar';
 import 'react-native-reanimated';
 
+import { ThemeProvider } from '@/context/ThemeContext';
 import { useColorScheme } from '@/hooks/use-color-scheme';
 
 export const unstable_settings = {
@@ -10,15 +11,23 @@ export const unstable_settings = {
 };
 
 export default function RootLayout() {
+  return (
+    <ThemeProvider>
+      <RootLayoutNav />
+    </ThemeProvider>
+  );
+}
+
+function RootLayoutNav() {
   const colorScheme = useColorScheme();
 
   return (
-    <ThemeProvider value={colorScheme === 'dark' ? DarkTheme : DefaultTheme}>
+    <NavigationThemeProvider value={colorScheme === 'dark' ? DarkTheme : DefaultTheme}>
       <Stack>
         <Stack.Screen name="(tabs)" options={{ headerShown: false }} />
         <Stack.Screen name="modal" options={{ presentation: 'modal', title: 'Modal' }} />
       </Stack>
       <StatusBar style="auto" />
-    </ThemeProvider>
+    </NavigationThemeProvider>
   );
 }

MobileApp/components/ui/icon-symbol.tsx

@@ -21,6 +21,7 @@ const MAPPING = {
   'bell.fill': 'notifications',
   'film.fill': 'video-library',
   'gearshape.fill': 'settings',
+  'checkmark': 'check',
 } as IconMapping;
 
 /**

MobileApp/context/ThemeContext.tsx

@@ -0,0 +1,60 @@
+import AsyncStorage from '@react-native-async-storage/async-storage';
+import React, { createContext, useContext, useEffect, useState } from 'react';
+import { useColorScheme as useNativeColorScheme } from 'react-native';
+
+type ThemeMode = 'light' | 'dark' | 'system';
+
+interface ThemeContextType {
+    themeMode: ThemeMode;
+    setThemeMode: (mode: ThemeMode) => void;
+    colorScheme: 'light' | 'dark'; // The actual active scheme
+}
+
+const ThemeContext = createContext<ThemeContextType>({
+    themeMode: 'system',
+    setThemeMode: () => { },
+    colorScheme: 'light',
+});
+
+export const THEME_STORAGE_KEY = 'user_theme_preference';
+
+export function ThemeProvider({ children }: { children: React.ReactNode }) {
+    const systemColorScheme = useNativeColorScheme();
+    const [themeMode, setThemeModeState] = useState<ThemeMode>('system');
+    const [isReady, setIsReady] = useState(false);
+
+    useEffect(() => {
+        // Load preference from storage on mount
+        AsyncStorage.getItem(THEME_STORAGE_KEY).then((value) => {
+            if (value && (value === 'light' || value === 'dark' || value === 'system')) {
+                setThemeModeState(value as ThemeMode);
+            }
+            setIsReady(true);
+        });
+    }, []);
+
+    const setThemeMode = async (mode: ThemeMode) => {
+        setThemeModeState(mode);
+        await AsyncStorage.setItem(THEME_STORAGE_KEY, mode);
+    };
+
+    // Determine effective color scheme
+    const colorScheme =
+        themeMode === 'system'
+            ? (systemColorScheme ?? 'light')
+            : themeMode;
+
+    if (!isReady) {
+        return null; // Or a splash screen
+    }
+
+    return (
+        <ThemeContext.Provider value={{ themeMode, setThemeMode, colorScheme }}>
+            {children}
+        </ThemeContext.Provider>
+    );
+}
+
+export function useTheme() {
+    return useContext(ThemeContext);
+}

MobileApp/hooks/use-color-scheme.ts

@@ -1 +1,6 @@
-export { useColorScheme } from 'react-native';
+import { useTheme } from '@/context/ThemeContext';
+
+export function useColorScheme() {
+    const { colorScheme } = useTheme();
+    return colorScheme;
+}

MobileApp/package-lock.json

@@ -9,6 +9,7 @@
       "version": "1.0.0",
       "dependencies": {
         "@expo/vector-icons": "^15.0.3",
+        "@react-native-async-storage/async-storage": "2.2.0",
         "@react-navigation/bottom-tabs": "^7.4.0",
         "@react-navigation/elements": "^2.6.3",
         "@react-navigation/native": "^7.1.8",
@@ -2777,6 +2778,18 @@
         }
       }
     },
+    "node_modules/@react-native-async-storage/async-storage": {
+      "version": "2.2.0",
+      "resolved": "https://registry.npmjs.org/@react-native-async-storage/async-storage/-/async-storage-2.2.0.tgz",
+      "integrity": "sha512-gvRvjR5JAaUZF8tv2Kcq/Gbt3JHwbKFYfmb445rhOj6NUMx3qPLixmDx5pZAyb9at1bYvJ4/eTUipU5aki45xw==",
+      "license": "MIT",
+      "dependencies": {
+        "merge-options": "^3.0.4"
+      },
+      "peerDependencies": {
+        "react-native": "^0.0.0-0 || >=0.65 <1.0"
+      }
+    },
     "node_modules/@react-native/assets-registry": {
       "version": "0.81.5",
       "resolved": "https://registry.npmjs.org/@react-native/assets-registry/-/assets-registry-0.81.5.tgz",
@@ -7810,6 +7823,15 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
+    "node_modules/is-plain-obj": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/is-plain-obj/-/is-plain-obj-2.1.0.tgz",
+      "integrity": "sha512-YWnfyRwxL/+SsrWYfOpUtz5b3YD+nyfkHvjbcanzk8zgyO4ASD67uVMRt8k5bM4lLMDnXfriRhOpemw+NfT1eA==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=8"
+      }
+    },
     "node_modules/is-regex": {
       "version": "1.2.1",
       "resolved": "https://registry.npmjs.org/is-regex/-/is-regex-1.2.1.tgz",
@@ -8788,6 +8810,18 @@
       "integrity": "sha512-zYiwtZUcYyXKo/np96AGZAckk+FWWsUdJ3cHGGmld7+AhvcWmQyGCYUh1hc4Q/pkOhb65dQR/pqCyK0cOaHz4Q==",
       "license": "MIT"
     },
+    "node_modules/merge-options": {
+      "version": "3.0.4",
+      "resolved": "https://registry.npmjs.org/merge-options/-/merge-options-3.0.4.tgz",
+      "integrity": "sha512-2Sug1+knBjkaMsMgf1ctR1Ujx+Ayku4EdJN4Z+C2+JzoeF7A3OZ9KM2GY0CpQS51NR61LTurMJrRKPhSs3ZRTQ==",
+      "license": "MIT",
+      "dependencies": {
+        "is-plain-obj": "^2.1.0"
+      },
+      "engines": {
+        "node": ">=10"
+      }
+    },
     "node_modules/merge-stream": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/merge-stream/-/merge-stream-2.0.0.tgz",

MobileApp/package.json

@@ -12,6 +12,7 @@
   },
   "dependencies": {
     "@expo/vector-icons": "^15.0.3",
+    "@react-native-async-storage/async-storage": "2.2.0",
     "@react-navigation/bottom-tabs": "^7.4.0",
     "@react-navigation/elements": "^2.6.3",
     "@react-navigation/native": "^7.1.8",
@@ -31,11 +32,11 @@
     "react-dom": "19.1.0",
     "react-native": "0.81.5",
     "react-native-gesture-handler": "~2.28.0",
-    "react-native-worklets": "0.5.1",
     "react-native-reanimated": "~4.1.1",
     "react-native-safe-area-context": "~5.6.0",
     "react-native-screens": "~4.16.0",
-    "react-native-web": "~0.21.0"
+    "react-native-web": "~0.21.0",
+    "react-native-worklets": "0.5.1"
   },
   "devDependencies": {
     "@types/react": "~19.1.0",