feat(chat): 发收消息全量实现 (#25~#28)

- 移除 @riverpod/@freezed 注解依赖，全部改为手写 Provider（无需 build_runner）
  · LoginState 改为纯 Dart，LoginViewModel/ThemeViewModel/ChatViewModel 改为 Notifier
  · UserNotifier 改为 FamilyAsyncNotifier<User?,int>，mini_app_provider 改为手写 Provider
  · 15 个 StreamProvider/StreamProvider.family 从 @riverpod 迁移至手写

- 发送消息（#25）
  · SendMessageRequest/SendMessageResponse DTO
  · SendMessageUseCase：乐观写入 DB → HTTP POST → 更新 Chat 摘要

- 接收消息 WS（#26）
  · WsMessageService：监听 mode2 WS 帧 → HTTP 补拉 → DB 写入 → Chat 更新
  · FetchHistoryRequest/FetchHistoryResponse DTO（GET /app/api/chat/history）
  · FetchHistoryUseCase：拉取 → insertOrReplaceAll

- DI 装配（chat_service_providers.dart）
  · wsMessageServiceProvider、sendMessageUseCaseProvider、fetchHistoryUseCaseProvider

- 聊天列表页（#27）
  · ChatListViewModel（Notifier<void>）+ chat_page.dart 真实会话列表 UI
  · ListTile：头像首字母、最新消息摘要、未读角标、时间格式化

- 聊天详情页（#28）
  · ChatDetailViewModel（FamilyNotifier<ChatDetailState,int>）+ chat_detail_page.dart
  · 消息气泡（自己/他人分左右）、底部输入框、发送状态与错误提示

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/im_app/lib/features/app_tab/di/favorite_detail_provider.dart

@@ -2,11 +2,8 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:im_app/app/di/db_provider.dart';
 import 'package:im_app/data/repositories/favorite_detail_repository_impl.dart';
 import 'package:im_app/domain/repositories/favorite_detail_repository.dart';
-import 'package:riverpod_annotation/riverpod_annotation.dart';
 import 'package:im_app/domain/entities/favorite_detail.dart';
 
-part 'favorite_detail_provider.g.dart';
-
 // ── Repository ────────────────────────────────────────────────────────────────
 
 /// 收藏详情仓储 Provider
@@ -19,18 +16,13 @@ final favoriteDetailRepositoryProvider = Provider<FavoriteDetailRepository>((
 // ── Streams ───────────────────────────────────────────────────────────────────
 
 /// 监听所有收藏详情
-@riverpod
-Stream<List<FavoriteDetail>> allFavoriteDetails(Ref ref) {
+final allFavoriteDetailsProvider = StreamProvider<List<FavoriteDetail>>((ref) {
   return ref.watch(favoriteDetailRepositoryProvider).watchAll();
-}
+});
 
 /// 监听指定 relatedId 的收藏详情
-@riverpod
-Stream<List<FavoriteDetail>> favoriteDetailsByRelatedId(
-  Ref ref,
-  String relatedId,
-) {
+final favoriteDetailsByRelatedIdProvider = StreamProvider.family<List<FavoriteDetail>, String>((ref, relatedId) {
   return ref
       .watch(favoriteDetailRepositoryProvider)
       .watchByRelatedId(relatedId);
-}
+});

apps/im_app/lib/features/app_tab/di/favorite_provider.dart

@@ -3,9 +3,6 @@ import 'package:im_app/app/di/db_provider.dart';
 import 'package:im_app/data/repositories/favorite_repository_impl.dart';
 import 'package:im_app/domain/entities/favorite.dart';
 import 'package:im_app/domain/repositories/favorite_repository.dart';
-import 'package:riverpod_annotation/riverpod_annotation.dart';
-
-part 'favorite_provider.g.dart';
 
 // ── Repository ────────────────────────────────────────────────────────────────
 
@@ -17,19 +14,16 @@ final favoriteRepositoryProvider = Provider<FavoriteRepository>((ref) {
 // ── Streams ───────────────────────────────────────────────────────────────────
 
 /// 监听所有收藏
-@riverpod
-Stream<List<Favorite>> allFavorites(Ref ref) {
+final allFavoritesProvider = StreamProvider<List<Favorite>>((ref) {
   return ref.watch(favoriteRepositoryProvider).watchAll();
-}
+});
 
 /// 监听指定收藏
-@riverpod
-Stream<Favorite?> favoriteById(Ref ref, int id) {
+final favoriteByIdProvider = StreamProvider.family<Favorite?, int>((ref, id) {
   return ref.watch(favoriteRepositoryProvider).watchById(id);
-}
+});
 
 /// 监听指定 parentId 的收藏
-@riverpod
-Stream<List<Favorite>> favoritesByParentId(Ref ref, String parentId) {
+final favoritesByParentIdProvider = StreamProvider.family<List<Favorite>, String>((ref, parentId) {
   return ref.watch(favoriteRepositoryProvider).watchByParentId(parentId);
-}
+});