Add streaks, scheduled releases, and notification settings

- Couple streaks with milestone notifications
- Scheduled pack releases with admin UI
- Notification preferences screen
- Refactored profile settings screens
- Partner activity notifications

apps/mobile/src/features/profile/screens/AccountScreen.tsx

@@ -0,0 +1,60 @@
+import React from 'react';
+import { View, ScrollView, StyleSheet, Platform } from 'react-native';
+
+import { GradientBackground } from '../../../components/ui';
+import { colors, spacing } from '../../../theme';
+import { useAuthStore } from '../../../store';
+import { useCoupleManagement } from '../hooks';
+import { ScreenHeader, SettingsSection, MenuItem, DangerZone } from '../components';
+
+/**
+ * Account settings sub-screen (sign out, delete account).
+ */
+export function AccountScreen() {
+    const { couple } = useAuthStore();
+    const { handleSignOut, handleDeleteAccount } = useCoupleManagement();
+
+    return (
+        <GradientBackground>
+            <ScreenHeader title="Account" />
+            <ScrollView
+                style={styles.container}
+                contentContainerStyle={styles.content}
+                showsVerticalScrollIndicator={false}
+            >
+                <SettingsSection title="Account" delay={0}>
+                    <MenuItem
+                        icon="log-out-outline"
+                        label="Sign Out"
+                        onPress={handleSignOut}
+                        variant="danger"
+                        showChevron={false}
+                    />
+                </SettingsSection>
+
+                <View style={styles.spacer} />
+
+                {/* Account Danger Zone - delete account only */}
+                <DangerZone
+                    onDeleteAccount={handleDeleteAccount}
+                    hasRelationship={!!couple}
+                />
+            </ScrollView>
+        </GradientBackground>
+    );
+}
+
+const styles = StyleSheet.create({
+    container: {
+        flex: 1,
+    },
+    content: {
+        paddingTop: spacing.lg,
+        paddingBottom: Platform.OS === 'ios' ? 40 : 20,
+    },
+    spacer: {
+        height: spacing.md,
+    },
+});
+
+export default AccountScreen;