Add deep debugging logs to PreviewScreen to trace fatal crashes during render/image load

src/screens/PreviewScreen.tsx

@@ -65,6 +65,10 @@ export default function PreviewScreen({
   const [layout, setLayout] = useState<CollageLayout>('single');
   const [isProcessing, setIsProcessing] = useState<boolean>(false);
   const [statusMessage, setStatusMessage] = useState<string>('');
+  
+  React.useEffect(() => {
+    logger.log('PreviewScreen: render function executed');
+  });
 
   // Sticker state
   const [stickers, setStickers] = useState<StickerData[]>([]);
@@ -320,7 +324,14 @@ export default function PreviewScreen({
           <View style={[styles.collageCanvas, styles.stripCanvas]}>
             <View style={styles.stripContent}>
               {photoUris.slice(-3).map((uri, idx) => (
-                <Image key={idx} source={uri} style={styles.stripImage} contentFit="cover" />
+                <Image 
+                  key={idx} 
+                  source={uri} 
+                  style={styles.stripImage} 
+                  contentFit="cover" 
+                  onLoad={() => logger.log(`Image loaded successfully: ${uri}`)}
+                  onError={(e) => logger.error(`Image load failed: ${uri}`, e)}
+                />
               ))}
             </View>
             <View style={styles.collageFooter}>
@@ -334,7 +345,14 @@ export default function PreviewScreen({
           <View style={[styles.collageCanvas, styles.gridCanvas]}>
             <View style={styles.gridContainer}>
               {photoUris.slice(-4).map((uri, idx) => (
-                <Image key={idx} source={uri} style={styles.gridImage} contentFit="cover" />
+                <Image 
+                  key={idx} 
+                  source={uri} 
+                  style={styles.gridImage} 
+                  contentFit="cover" 
+                  onLoad={() => logger.log(`Grid Image loaded successfully: ${uri}`)}
+                  onError={(e) => logger.error(`Grid Image load failed: ${uri}`, e)}
+                />
               ))}
             </View>
             <View style={styles.collageFooter}>
@@ -347,7 +365,14 @@ export default function PreviewScreen({
           <View style={[styles.collageCanvas, styles.duoCanvas]}>
             <View style={styles.duoContainer}>
               {photoUris.slice(-2).map((uri, idx) => (
-                <Image key={idx} source={uri} style={styles.duoImage} contentFit="cover" />
+                <Image 
+                  key={idx} 
+                  source={uri} 
+                  style={styles.duoImage} 
+                  contentFit="cover" 
+                  onLoad={() => logger.log(`Duo Image loaded successfully: ${uri}`)}
+                  onError={(e) => logger.error(`Duo Image load failed: ${uri}`, e)}
+                />
               ))}
             </View>
             <View style={styles.collageFooter}>
@@ -362,6 +387,8 @@ export default function PreviewScreen({
               source={currentPhoto}
               style={styles.singleImage}
               contentFit="cover"
+              onLoad={() => logger.log(`Single Image loaded successfully: ${currentPhoto}`)}
+              onError={(e) => logger.error(`Single Image load failed: ${currentPhoto}`, e)}
             />
           </View>
         );