feat(receipt-import): add multipack count extraction from raw name and update package fields inference

flutter/lib/features/import/utils/receipt_import_utils.dart

@@ -74,6 +74,15 @@ bool isPackageLikeUnit(String? unit) {
   return (packQuantity: value, packUnit: sizeUnit);
 }
 
+double? extractMultipackCountFromRawName(String rawName) {
+  final match = RegExp(
+    r'(\d+)\s*[x×]\s*\d+(?:[\.,]\d+)?\s*(ml|cl|dl|l|g|kg)\b',
+    caseSensitive: false,
+  ).firstMatch(rawName);
+  if (match == null) return null;
+  return double.tryParse(match.group(1)!);
+}
+
 // ── Paketfältsinferens ────────────────────────────────────────────────────────
 
 typedef PackageFields = ({
@@ -92,6 +101,7 @@ PackageFields inferPackageFields({
   final normalizedUnit = unit?.trim().toLowerCase();
   final safeCount = (quantity != null && quantity > 0) ? quantity : 1.0;
   final extracted = extractPackageSizeFromRawName(rawName);
+  final multipackCount = extractMultipackCountFromRawName(rawName);
 
   // Om rånamnet innehåller storlek (t.ex. "5dl") och enhet saknas eller är
   // paketliknande — använd extraherad storlek.
@@ -99,11 +109,14 @@ PackageFields inferPackageFields({
       (normalizedUnit == null ||
           normalizedUnit.isEmpty ||
           isPackageLikeUnit(normalizedUnit))) {
+    final packageCount = multipackCount != null && multipackCount > 0
+        ? multipackCount
+        : safeCount;
     return (
       packQuantity: extracted.packQuantity,
       packUnit: extracted.packUnit,
-      packageCount: safeCount,
+      packageCount: packageCount,
-      totalQuantity: extracted.packQuantity * safeCount,
+      totalQuantity: extracted.packQuantity * packageCount,
       totalUnit: extracted.packUnit,
     );
   }