feat: 角色卡 demo

wei_ai_app/lib/providers/character_providers.dart

@@ -0,0 +1,68 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import '../core/core.dart';
+
+/// 分类列表 Provider
+final categoriesProvider = FutureProvider<List<CategoryModel>>((ref) async {
+  return CharacterRepository.getCategories();
+});
+
+/// 角色列表 Provider
+final charactersProvider = FutureProvider<List<CharacterModel>>((ref) async {
+  return CharacterRepository.getCharacters();
+});
+
+/// 当前选中的分类代码 Notifier
+class SelectedCategoryNotifier extends Notifier<String> {
+  @override
+  String build() => 'all';
+  
+  void setCategory(String code) {
+    state = code;
+  }
+}
+
+/// 当前选中的分类代码
+final selectedCategoryProvider = NotifierProvider<SelectedCategoryNotifier, String>(
+  SelectedCategoryNotifier.new,
+);
+
+/// 根据分类筛选后的角色列表
+final filteredCharactersProvider = Provider<AsyncValue<List<CharacterModel>>>((ref) {
+  final categoryCode = ref.watch(selectedCategoryProvider);
+  final charactersAsync = ref.watch(charactersProvider);
+  
+  return charactersAsync.when(
+    data: (characters) {
+      if (categoryCode == 'all') {
+        return AsyncValue.data(characters);
+      }
+      
+      // 本地筛选
+      final filtered = characters.where((c) {
+        final tags = c.tagNames.join('');
+        switch (categoryCode) {
+          case 'gentle':
+            return tags.contains('治愈') || tags.contains('温顺') || tags.contains('医疗');
+          case 'dom':
+            return tags.contains('强势') || tags.contains('调教') || tags.contains('指令');
+          case 'wild':
+            return tags.contains('病娇') || tags.contains('神秘') || 
+                   tags.contains('不稳定') || tags.contains('极乐');
+          case 'exclusive':
+            return c.isLocked;
+          default:
+            return false;
+        }
+      }).toList();
+      
+      return AsyncValue.data(filtered);
+    },
+    loading: () => const AsyncValue.loading(),
+    error: (e, st) => AsyncValue.error(e, st),
+  );
+});
+
+/// 单个角色详情 Provider
+final characterDetailProvider = FutureProvider.family<CharacterModel?, String>((ref, id) async {
+  return CharacterRepository.getCharacterById(id);
+});