Add on-device logger

App.tsx

@@ -4,7 +4,15 @@ import { GestureHandlerRootView } from 'react-native-gesture-handler';
 import CameraScreen from './src/screens/CameraScreen';
 import PreviewScreen from './src/screens/PreviewScreen';
 import AdminScreen from './src/screens/AdminScreen';
-import { loadSettings, AppSettings } from './src/services/settings';
+import { loadSettings, saveSettings, AppSettings } from './src/services/settings';
+import { logger } from './src/services/logger';
+
+// Set up global error handler
+const defaultErrorHandler = (global as any).ErrorUtils.getGlobalHandler();
+(global as any).ErrorUtils.setGlobalHandler(async (error: any, isFatal: boolean) => {
+  await logger.error(`Unhandled Exception (Fatal: ${isFatal})`, error);
+  defaultErrorHandler(error, isFatal);
+});
 import KioskMode from './modules/kiosk-mode';
 
 type ScreenState = 'home' | 'camera' | 'preview' | 'admin';
@@ -42,9 +50,15 @@ export default function App() {
     setCurrentScreen('camera');
   };
 
-  const handlePhotoCaptured = (uri: string) => {
-    setPhotoUris((prev) => [...prev, uri]);
-    setCurrentScreen('preview');
+  const handlePhotoCaptured = async (uri: string) => {
+    await logger.log(`Photo captured via CameraScreen: ${uri}`);
+    try {
+      setPhotoUris((prev) => [...prev, uri]);
+      setCurrentScreen('preview');
+      await logger.log('State updated to preview screen successfully.');
+    } catch (e) {
+      await logger.error('Error transitioning to preview screen:', e);
+    }
   };
 
   // Called by CameraScreen when burst mode completes all photos