feat: implement payment profile management and caregiver authentication services with theme and UI components

src/components/ui/Header.tsx

@@ -10,9 +10,10 @@ interface HeaderProps {
   title: string;
   showBack?: boolean;
   rightComponent?: React.ReactNode;
+  onBack?: () => void;
 }
 
-export const Header: React.FC<HeaderProps> = ({ title, showBack = false, rightComponent }) => {
+export const Header: React.FC<HeaderProps> = ({ title, showBack = false, rightComponent, onBack }) => {
   const navigation = useNavigation();
   const { screenPadding } = useResponsiveLayout();
 
@@ -21,7 +22,7 @@ export const Header: React.FC<HeaderProps> = ({ title, showBack = false, rightCo
       <View style={styles.leftContainer}>
         {showBack && (
           <TouchableOpacity 
-            onPress={() => navigation.goBack()} 
+            onPress={() => onBack ? onBack() : navigation.goBack()} 
             style={styles.backButton}
             hitSlop={{ top: 10, bottom: 10, left: 10, right: 10 }}
           >