update

lib/features/categories/provider.dart

@@ -0,0 +1,14 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import '../../shared/models/transaction.dart';
+import '../dashboard/provider.dart';
+
+final categoryExpenseProvider = Provider<Map<String, double>>((ref) {
+  final txs = ref.watch(transactionsProvider)
+      .where((t) => t.type == TransactionType.expense);
+
+  final map = <String, double>{};
+  for (final t in txs) {
+    map[t.category] = (map[t.category] ?? 0) + t.amount;
+  }
+  return map;
+});