improve parsing

lib/services/receipt_parse_config.dart

@@ -25,6 +25,8 @@ class ReceiptParseConfig {
     required this.trailingCategoryLetter,
     required this.noiseKeywords,
     required this.itemCountKeywords,
+    this.rowClusterHeightFactor = 1.2,
+    this.priceColumnWidthFraction = 0.25,
   });
 
   final List<String> knownStores;
@@ -44,6 +46,8 @@ class ReceiptParseConfig {
   final RegExp trailingCategoryLetter;
   final List<String> noiseKeywords;
   final List<String> itemCountKeywords;
+  final double rowClusterHeightFactor;
+  final double priceColumnWidthFraction;
 
   factory ReceiptParseConfig.fromJson(Map<String, dynamic> json) {
     List<String> list(String section, [String key = 'list']) {
@@ -99,9 +103,31 @@ class ReceiptParseConfig {
       ),
       noiseKeywords: list('noise_footer_keywords'),
       itemCountKeywords: list('line_item_count_keywords'),
+      rowClusterHeightFactor: _spatialDouble(
+        json,
+        'row_cluster_height_factor',
+        fallback: 1.2,
+      ),
+      priceColumnWidthFraction: _spatialDouble(
+        json,
+        'price_column_width_fraction',
+        fallback: 0.25,
+      ),
     );
   }
 
+  static double _spatialDouble(
+    Map<String, dynamic> json,
+    String key, {
+    required double fallback,
+  }) {
+    final spatial = json['spatial_parsing'];
+    if (spatial is! Map) return fallback;
+    final value = spatial[key];
+    if (value is num && value > 0) return value.toDouble();
+    return fallback;
+  }
+
   static const assetPath = 'receipt-parsing-keywords.json';
 
   /// True if [line] matches a config keyword.