Fix final 4 resilience edge cases

App.tsx

@@ -81,7 +81,8 @@ export default function App() {
   const handleBurstComplete = (uris: string[]) => {
     setPhotoUris((prev) => {
       const next = [...prev, ...uris];
-      return next.length > 4 ? next.slice(-4) : next;
+      const maxKeep = Math.max(4, uris.length);
+      return next.length > maxKeep ? next.slice(-maxKeep) : next;
     });
     setCaptureHistory((prev) => [...prev, uris.length]);
     setCurrentScreen('preview');

src/components/DraggableSticker.tsx

@@ -152,6 +152,7 @@ const styles = StyleSheet.create({
     position: 'absolute',
     alignItems: 'center',
     justifyContent: 'center',
+    zIndex: 100,
   },
   emojiText: {
     fontSize: 48,
@@ -184,6 +185,7 @@ const styles = StyleSheet.create({
     backgroundColor: THEME.colors.error,
     alignItems: 'center',
     justifyContent: 'center',
+    zIndex: 200,
   },
   deleteBtnText: {
     color: '#fff',

src/screens/CameraScreen.tsx

@@ -23,7 +23,7 @@ import Animated, {
   FadeIn,
   FadeOut,
   withSequence,
-  Easing,
+  withDelay,
   runOnJS,
 } from 'react-native-reanimated';
 import { FontAwesomeIcon } from '@fortawesome/react-native-fontawesome';
@@ -210,16 +210,8 @@ export default function CameraScreen({
     if (burstTimerRef.current) clearTimeout(burstTimerRef.current);
     if (countdownTimerRef.current) clearTimeout(countdownTimerRef.current);
     if (completionTimerRef.current) clearTimeout(completionTimerRef.current);
-    
-    // Clean up any temp files from a partially completed burst
-    for (const uri of burstUris) {
-      try {
-        await FileSystem.deleteAsync(uri, { idempotent: true });
-      } catch (e) {
-        console.warn('Failed to delete temp file on cancel:', e);
-      }
-    }
-    
+    const urisToDelete = [...burstUris];
+
     setCountdown(countdownDuration);
     setIsCapturing(false);
     setIsBurstWaiting(false);
@@ -228,6 +220,15 @@ export default function CameraScreen({
     setBurstUris([]);
     setShowBurstIndicator('');
     onCancel();
+
+    // Clean up any temp files from a partially completed burst in the background
+    Promise.all(
+      urisToDelete.map(uri =>
+        FileSystem.deleteAsync(uri, { idempotent: true }).catch(e => {
+          console.warn('Failed to delete temp file on cancel:', e);
+        })
+      )
+    );
   };
 
   // 3. Start the countdown on screen load (only when NOT idle)

src/screens/PreviewScreen.tsx

@@ -289,8 +289,8 @@ export default function PreviewScreen({
     }
   };
 
-  // Auto-save and exit
-  const handleExit = useCallback(async () => {
+  const handleExitRef = useRef<() => void>();
+  handleExitRef.current = async () => {
     if (idleTimerRef.current) clearTimeout(idleTimerRef.current);
     if (!mountedRef.current) return;
     if (isProcessing) return;
@@ -319,15 +319,20 @@ export default function PreviewScreen({
       setIsProcessing(false);
       state.onReset();
     }
-  }, []); // Stable reference
+  };
+
+  // Auto-save and exit
+  const handleExit = useCallback(async () => {
+    if (handleExitRef.current) handleExitRef.current();
+  }, []);
 
   // Idle timer logic
   const resetIdleTimer = useCallback(() => {
     if (idleTimerRef.current) clearTimeout(idleTimerRef.current);
     idleTimerRef.current = setTimeout(() => {
-      handleExit();
+      if (handleExitRef.current) handleExitRef.current();
     }, 60000);
-  }, [handleExit]);
+  }, []);
 
   useEffect(() => {
     resetIdleTimer();