fix(receipt-import): infer size from raw name when unit is missing

flutter/lib/features/import/presentation/receipt_import_tab.dart

@@ -63,7 +63,23 @@ bool _isPackageLikeUnit(String? unit) {
   required double? quantity,
   required String? unit,
 }) {
-  if (quantity == null || unit == null) {
+  final normalizedUnit = unit?.trim().toLowerCase();
+  final safeCount = (quantity != null && quantity > 0) ? quantity : 1.0;
+  final extracted = _extractPackageSizeFromRawName(rawName);
+
+  // If the receipt name contains size (e.g. "5dl"), prefer it when unit is
+  // missing/unknown or when OCR reports package-like count units (st/pkt/etc).
+  if (extracted != null && (normalizedUnit == null || normalizedUnit.isEmpty || _isPackageLikeUnit(normalizedUnit))) {
+    return (
+      packQuantity: extracted.packQuantity,
+      packUnit: extracted.packUnit,
+      packageCount: safeCount,
+      totalQuantity: extracted.packQuantity * safeCount,
+      totalUnit: extracted.packUnit,
+    );
+  }
+
+  if (quantity == null || normalizedUnit == null || normalizedUnit.isEmpty) {
     return (
       packQuantity: null,
       packUnit: null,
@@ -73,8 +89,7 @@ bool _isPackageLikeUnit(String? unit) {
     );
   }
 
-  final looksLikePackage = _isPackageLikeUnit(unit);
+  final looksLikePackage = _isPackageLikeUnit(normalizedUnit);
-  final extracted = _extractPackageSizeFromRawName(rawName);
 
   if (looksLikePackage && extracted != null) {
     return (
@@ -88,10 +103,10 @@ bool _isPackageLikeUnit(String? unit) {
 
   return (
     packQuantity: quantity,
-    packUnit: unit,
+    packUnit: normalizedUnit,
     packageCount: 1,
     totalQuantity: quantity,
-    totalUnit: unit,
+    totalUnit: normalizedUnit,
   );
 }