EnakPromo: halaman promo dan detail promo

- Banner promo unggulan, info cara dapat, filter per tipe hadiah, daftar
  promo berlangsung dan segera hadir
- Detail promo: hadiah, periode, outlet, cara dapat, S&K, CTA ke Reward
  Saya atau daftar outlet
- Data contoh mengikuti bentuk campaign backend (POINTS/COINS/REWARD)
- Filter chip Reward Saya dipindah ke komponen bersama FilterBarDelegate

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

lib/presentation/components/delegate/filter_bar_delegate.dart

@@ -0,0 +1,62 @@
+import 'package:flutter/material.dart';
+
+import '../../../common/theme/theme.dart';
+import '../chip/app_filter_chip.dart';
+
+/// Baris [AppFilterChip] yang bisa di-scroll menyamping, untuk
+/// [SliverPersistentHeader] yang menempel di atas daftar.
+class FilterBarDelegate<T> extends SliverPersistentHeaderDelegate {
+  FilterBarDelegate({
+    required this.values,
+    required this.selected,
+    required this.labelOf,
+    required this.countOf,
+    required this.onSelected,
+    this.backgroundColor = AppColor.background,
+  });
+
+  final List<T> values;
+  final T selected;
+  final String Function(T value) labelOf;
+  final int Function(T value) countOf;
+  final ValueChanged<T> onSelected;
+  final Color backgroundColor;
+
+  static const double _height = 56;
+
+  @override
+  double get minExtent => _height;
+
+  @override
+  double get maxExtent => _height;
+
+  @override
+  Widget build(
+    BuildContext context,
+    double shrinkOffset,
+    bool overlapsContent,
+  ) {
+    return Container(
+      color: backgroundColor,
+      child: ListView.separated(
+        scrollDirection: Axis.horizontal,
+        padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 10),
+        itemCount: values.length,
+        separatorBuilder: (_, _) => const SizedBox(width: 8),
+        itemBuilder: (context, index) {
+          final value = values[index];
+          return AppFilterChip(
+            label: labelOf(value),
+            count: countOf(value),
+            isSelected: value == selected,
+            onTap: () => onSelected(value),
+          );
+        },
+      ),
+    );
+  }
+
+  @override
+  bool shouldRebuild(covariant FilterBarDelegate<T> oldDelegate) =>
+      oldDelegate.selected != selected || oldDelegate.values != values;
+}