feat(ui): Implement Developer Menu & A/B Testing (Grid/FAB)

lib/providers/ui_experiment_provider.dart

@@ -0,0 +1,39 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+// UI実験設定クラス
+class UiExperimentSettings {
+  final int gridColumns;        // 2 or 3
+  final String fabAnimation;    // 'rotate' or 'bounce'
+  
+  const UiExperimentSettings({
+    this.gridColumns = 2,
+    this.fabAnimation = 'rotate',
+  });
+  
+  UiExperimentSettings copyWith({
+    int? gridColumns,
+    String? fabAnimation,
+  }) {
+    return UiExperimentSettings(
+      gridColumns: gridColumns ?? this.gridColumns,
+      fabAnimation: fabAnimation ?? this.fabAnimation,
+    );
+  }
+}
+
+// Provider
+final uiExperimentProvider = StateNotifierProvider<UiExperimentNotifier, UiExperimentSettings>(
+  (ref) => UiExperimentNotifier(),
+);
+
+class UiExperimentNotifier extends StateNotifier<UiExperimentSettings> {
+  UiExperimentNotifier() : super(const UiExperimentSettings());
+  
+  void setGridColumns(int columns) {
+    state = state.copyWith(gridColumns: columns);
+  }
+  
+  void setFabAnimation(String animation) {
+    state = state.copyWith(fabAnimation: animation);
+  }
+}

lib/screens/dev_menu_screen.dart

@@ -0,0 +1,52 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:lucide_icons/lucide_icons.dart';
+import '../providers/ui_experiment_provider.dart';
+
+class DevMenuScreen extends ConsumerWidget {
+  const DevMenuScreen({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final experiment = ref.watch(uiExperimentProvider);
+    
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text('🔬 開発者メニュー'),
+      ),
+      body: ListView(
+        children: [
+          const ListTile(
+            leading: Icon(LucideIcons.flaskConical),
+            title: Text('UI実験'),
+            subtitle: Text('新しいデザインのテスト'),
+          ),
+          Card(
+            margin: const EdgeInsets.all(16),
+            child: Column(
+              children: [
+                SwitchListTile(
+                  secondary: const Text('📱', style: TextStyle(fontSize: 24)),
+                  title: const Text('グリッド3列表示'),
+                  subtitle: Text('瓶型の縦長カード (現在: ${experiment.gridColumns}列)'),
+                  value: experiment.gridColumns == 3,
+                  onChanged: (val) => ref.read(uiExperimentProvider.notifier)
+                      .setGridColumns(val ? 3 : 2),
+                ),
+                const Divider(),
+                SwitchListTile(
+                  secondary: const Text('✨', style: TextStyle(fontSize: 24)),
+                  title: const Text('FABバウンス'),
+                  subtitle: Text('ぷるんとした動き (現在: ${experiment.fabAnimation == 'bounce' ? 'ON' : 'OFF'})'),
+                  value: experiment.fabAnimation == 'bounce',
+                  onChanged: (val) => ref.read(uiExperimentProvider.notifier)
+                      .setFabAnimation(val ? 'bounce' : 'rotate'),
+                ),
+              ],
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}

lib/screens/home_screen.dart

@@ -24,9 +24,10 @@ import '../widgets/onboarding_dialog.dart';
 import '../widgets/home/sake_filter_chips.dart';
 import '../widgets/home/home_empty_state.dart';
 import '../widgets/home/sake_no_match_state.dart';
-import '../widgets/home/sake_list_view.dart';
-import '../widgets/home/sake_grid_view.dart';
-import '../widgets/add_set_item_dialog.dart';
+import '../models/user_profile.dart'; // UserProfile
+import '../widgets/analyzing_dialog.dart';
+import '../widgets/empty_state.dart'; // Generic empty state
+import '../providers/ui_experiment_provider.dart'; // A/B Test
 import 'package:flutter_speed_dial/flutter_speed_dial.dart';
 import 'package:lucide_icons/lucide_icons.dart';
 import '../widgets/prefecture_filter_sheet.dart';
@@ -210,6 +211,15 @@ class HomeScreen extends ConsumerWidget {
               activeBackgroundColor: Colors.grey[800],
               overlayColor: Colors.black,
               overlayOpacity: 0.5,
+              
+              // A/B Test Animation
+              animationCurve: ref.watch(uiExperimentProvider).fabAnimation == 'bounce' 
+                  ? Curves.elasticOut 
+                  : Curves.linear,
+              animationDuration: ref.watch(uiExperimentProvider).fabAnimation == 'bounce'
+                  ? const Duration(milliseconds: 400)
+                  : const Duration(milliseconds: 250),
+
               spacing: 12,
               spaceBetweenChildren: 12,
               children: [

lib/widgets/home/sake_grid_view.dart

@@ -5,6 +5,7 @@ import 'package:flutter/services.dart'; // HapticFeedback
 
 import '../../models/sake_item.dart';
 import '../../providers/sake_list_provider.dart'; // For sakeOrderControllerProvider
+import '../../providers/ui_experiment_provider.dart'; // A/B Test
 import 'sake_grid_item.dart';
 
 class SakeGridView extends ConsumerWidget {
@@ -23,15 +24,17 @@ class SakeGridView extends ConsumerWidget {
   Widget build(BuildContext context, WidgetRef ref) {
     final list = sakeList.cast<SakeItem>();
 
+    final experiment = ref.watch(uiExperimentProvider);
+
     // If reorder is disabled (Menu Creation Screen), use standard GridView
     if (!enableReorder || isMenuMode) {
       return GridView.builder(
         padding: const EdgeInsets.all(4),
-        gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
-          crossAxisCount: 2,
+        gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
+          crossAxisCount: experiment.gridColumns,
           crossAxisSpacing: 4,
           mainAxisSpacing: 4,
-          childAspectRatio: 1.0,
+          childAspectRatio: experiment.gridColumns == 3 ? (1.0 / 1.5) : 1.0,
         ),
         itemCount: list.length,
         itemBuilder: (context, index) {
@@ -47,11 +50,11 @@ class SakeGridView extends ConsumerWidget {
     // Standard ReorderableGridView for Home Screen
     return ReorderableGridView.builder(
       padding: const EdgeInsets.all(4),
-      gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
-        crossAxisCount: 2,
+      gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
+        crossAxisCount: experiment.gridColumns,
         crossAxisSpacing: 4,
         mainAxisSpacing: 4,
-        childAspectRatio: 1.0,
+        childAspectRatio: experiment.gridColumns == 3 ? (1.0 / 1.5) : 1.0,
       ),
       itemCount: list.length,
       onReorder: (oldIndex, newIndex) {

lib/widgets/settings/other_settings_section.dart

@@ -2,6 +2,8 @@ import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:lucide_icons/lucide_icons.dart';
 import 'package:package_info_plus/package_info_plus.dart';
+import 'package:flutter/services.dart';
+import '../../screens/dev_menu_screen.dart';
 import '../../providers/theme_provider.dart';
 
 class OtherSettingsSection extends ConsumerStatefulWidget {
@@ -20,6 +22,7 @@ class OtherSettingsSection extends ConsumerStatefulWidget {
 
 class _OtherSettingsSectionState extends ConsumerState<OtherSettingsSection> {
   String _appVersion = 'Loading...';
+  int _devTapCount = 0;
 
   @override
   void initState() {
@@ -64,6 +67,22 @@ class _OtherSettingsSectionState extends ConsumerState<OtherSettingsSection> {
                  leading: Icon(LucideIcons.info, color: isDark ? Colors.grey[400] : null),
                  title: const Text('アプリバージョン'),
                  subtitle: Text(_appVersion),
+                 onTap: () {
+                   setState(() {
+                     _devTapCount++;
+                     if (_devTapCount >= 5) {
+                       _devTapCount = 0;
+                       HapticFeedback.heavyImpact();
+                       Navigator.push(
+                         context,
+                         MaterialPageRoute(builder: (context) => const DevMenuScreen()),
+                       );
+                     } else {
+                        // Optional: Small feedback
+                        HapticFeedback.lightImpact();
+                     }
+                   });
+                 },
                ),
             ],
           ),