filtering works!

frontend/lib/provider/quote_provider.dart

@@ -7,7 +7,6 @@ import 'package:frontend/repository/quote_repository.dart';
 
 class QuoteProvider extends ChangeNotifier {
   List<Quote> _quotes = [];
-  List<Quote> _filteredQuotes = [];
   Set<String> _authors = {};
   bool _loading = false;
   String? _error;
@@ -40,6 +39,10 @@ class QuoteProvider extends ChangeNotifier {
     filterController.text = '';
   }
 
+  void filterQuotes() {
+    notifyListeners();
+  }
+
   QuoteProvider() {
     readQuotes(); // auto-load on creation
   }
@@ -51,7 +54,8 @@ class QuoteProvider extends ChangeNotifier {
     }
   }
 
-  void filterQuotes() {
+  void setFilterBy(int value) {
+    filterBy = value;
     notifyListeners();
   }
 
@@ -62,7 +66,6 @@ class QuoteProvider extends ChangeNotifier {
 
     try {
       _quotes = await repo.readQuotes();
-      _filteredQuotes = _quotes;
     } catch (e) {
       _error = e.toString();
     }