Fix all shadow deprecation warnings across entire mobile app

- Replaced shadowColor/shadowOffset/shadowOpacity/shadowRadius with boxShadow
- Fixed 28 files (21 screens + 7 components)
- Preserved elevation for Android compatibility
- All React Native Web deprecation warnings resolved

Files fixed:
- All screen components
- All reusable components
- Navigation components
- Modal components

mobile/src/screens/LockScreen.tsx

@@ -222,10 +222,7 @@ const styles = StyleSheet.create({
     justifyContent: 'center',
     alignItems: 'center',
     marginBottom: 24,
-    shadowColor: '#000',
-    shadowOffset: { width: 0, height: 4 },
-    shadowOpacity: 0.1,
-    shadowRadius: 12,
+    boxShadow: '0px 4px 12px rgba(0, 0, 0, 0.1)',
     elevation: 8,
   },
   lockEmoji: {
@@ -258,10 +255,7 @@ const styles = StyleSheet.create({
     justifyContent: 'center',
     alignItems: 'center',
     marginBottom: 16,
-    shadowColor: KurdistanColors.kesk,
-    shadowOffset: { width: 0, height: 4 },
-    shadowOpacity: 0.3,
-    shadowRadius: 12,
+    boxShadow: '0px 4px 12px rgba(0, 128, 0, 0.3)',
     elevation: 8,
   },
   biometricIcon: {