add build step for flutter web, add persistent pagination in the traction list

lib/components/pages/traction/traction_persistence.dart

@@ -39,6 +39,16 @@ extension _TractionPersistence on _TractionPageState {
           enumValues[entry.key.toString()] = entry.value?.toString();
         }
       }
+      final lastOffsetRaw = decoded['lastOffset'];
+      if (lastOffsetRaw is int) {
+        _lastTractionOffset = lastOffsetRaw;
+      } else if (lastOffsetRaw is num) {
+        _lastTractionOffset = lastOffsetRaw.toInt();
+      }
+      final lastSig = decoded['querySignature']?.toString();
+      if (lastSig != null && lastSig.isNotEmpty) {
+        _lastQuerySignature = lastSig;
+      }
 
       for (final entry in dynamicValues.entries) {
         _dynamicControllers.putIfAbsent(
@@ -76,6 +86,8 @@ extension _TractionPersistence on _TractionPageState {
       'showAdvancedFilters': _showAdvancedFilters,
       'dynamic': _dynamicControllers.map((k, v) => MapEntry(k, v.text)),
       'enum': _enumSelections,
+      'lastOffset': _lastTractionOffset,
+      'querySignature': _lastQuerySignature,
     };
 
     try {