Initial project

apps/im_app/lib/features/settings/presentation/settings_view_model.dart

@@ -0,0 +1,30 @@
+import 'package:flutter/material.dart';
+import 'package:go_router/go_router.dart';
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+
+import '../../../app/router/app_route_name.dart';
+
+part 'settings_view_model.g.dart';
+
+/// 设置页 ViewModel
+///
+/// ## 数据流位置
+///
+/// ```
+/// SettingsPage
+///   → ref.read(settingsViewModelProvider.notifier).navigateToTheme(context)
+///     → ★ SettingsViewModel.navigateToTheme() ★   ← 你在这里
+///       → context.push(AppRouteName.settingsTheme.path)
+/// ```
+///
+/// 导航意图由 ViewModel 统一管理，View 不直接调用路由。
+@riverpod
+class SettingsViewModel extends _$SettingsViewModel {
+  @override
+  void build() {}
+
+  /// 跳转到主题设置页。
+  void navigateToTheme(BuildContext context) {
+    context.push(AppRouteName.settingsTheme.path);
+  }
+}

apps/im_app/lib/features/settings/presentation/theme_view_model.dart

@@ -0,0 +1,37 @@
+import 'package:flutter/material.dart';
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+
+import '../../../app/di/app_providers.dart';
+import '../di/settings_providers.dart';
+
+part 'theme_view_model.g.dart';
+
+/// 主题 ViewModel
+///
+/// View 层只感知此 ViewModel，不直接依赖 app 级 Provider。
+///
+/// ## 数据流
+///
+/// ```
+/// ThemeView
+///   → ref.watch(themeViewModelProvider)              ← 当前 ThemeMode
+///   → ref.read(themeViewModelProvider.notifier).setMode(mode)
+///     → ★ ThemeViewModel.setMode() ★               ← 你在这里
+///       → SetThemeUseCase.execute()
+///         → 幂等校验（相同模式直接返回）
+///         → onApply → ThemeModeNotifier.setMode()   ← 更新内存状态
+///         → TODO: 持久化（storage_sdk）
+/// ```
+@riverpod
+class ThemeViewModel extends _$ThemeViewModel {
+  @override
+  ThemeMode build() => ref.watch(themeModeProvider);
+
+  void setMode(ThemeMode mode) {
+    ref.read(setThemeUseCaseProvider).execute(
+          current: state,
+          requested: mode,
+          onApply: (m) => ref.read(themeModeProvider.notifier).setMode(m),
+        );
+  }
+}