fix OCR in apx

lib/scan_screen.dart

@@ -103,10 +103,17 @@ class _ScanScreenState extends State<ScanScreen> {
           _error = 'No text found in this image.';
         }
       });
-    } catch (error) {
+    } on PlatformException catch (error) {
+      debugPrint('OCR failed: ${error.code} ${error.message}');
       if (!mounted) return;
       setState(() {
-        _error = 'Could not read text from this image.';
+        _error = _ocrFailureMessage(error.message);
+      });
+    } catch (error) {
+      debugPrint('OCR failed: $error');
+      if (!mounted) return;
+      setState(() {
+        _error = _ocrFailureMessage(error.toString());
       });
     } finally {
       await recognizer.close();
@@ -120,6 +127,12 @@ class _ScanScreenState extends State<ScanScreen> {
     }
   }
 
+  String _ocrFailureMessage(String? detail) {
+    const fallback = 'Could not read text from this image.';
+    if (detail == null || detail.trim().isEmpty) return fallback;
+    return '$fallback\n$detail';
+  }
+
   Future<void> _openReview(String rawText) async {
     final items = ReceiptParser.parse(rawText);
     if (!mounted) return;