fix: camera flash rendering and timing

src/screens/CameraScreen.tsx

@@ -126,12 +126,14 @@ export default function CameraScreen({
     opacity: flashOpacity.value,
   }));
 
-  // Trigger white flash effect
-  const triggerFlash = useCallback(() => {
-    flashOpacity.value = withSequence(
-      withTiming(1, { duration: 80 }),
-      withTiming(0, { duration: 400 })
-    );
+  // Turn on white flash effect
+  const turnFlashOn = useCallback(() => {
+    flashOpacity.value = withTiming(1, { duration: 50 });
+  }, []);
+
+  // Turn off white flash effect
+  const turnFlashOff = useCallback(() => {
+    flashOpacity.value = withTiming(0, { duration: 400 });
   }, []);
 
   // 1. Request built-in camera permission on mount (just in case we fallback)
@@ -314,7 +316,7 @@ export default function CameraScreen({
     const tempUri = tempFile.uri;
 
     try {
-      triggerFlash();
+      turnFlashOn();
 
       let capturedUri: string;
 
@@ -338,6 +340,8 @@ export default function CameraScreen({
         }
       }
 
+      turnFlashOff();
+
       // If user cancelled while the camera promise was processing, abort before side-effects
       if (isCancelledRef.current) {
         console.log('Capture cancelled by user during processing.');
@@ -403,6 +407,7 @@ export default function CameraScreen({
         }, 400);
       }
     } catch (error: any) {
+      turnFlashOff();
       console.error('Capture failed:', error);
       alert('Fehler beim Aufnehmen des Fotos: ' + error.message);
       onCancel();
@@ -674,6 +679,9 @@ export default function CameraScreen({
 
       {/* Render UI controls/overlays on top */}
       {renderContent()}
+
+      {/* Flash overlay */}
+      <Animated.View style={[styles.flashOverlay, flashAnimatedStyle]} pointerEvents="none" />
     </View>
   );
 }