refactor: 重构 Tool Result 契约，移除 ui_hints 统一使用 result 字段

- ToolAgentOutput 移除 result_summary 和 ui_hints，统一使用 result 字段
- 日历/用户查找工具移除 ui_hints 输出，改为机器可读的结构化结果
- Agent History 移除 tool 消息的 ui_hints 处理逻辑
- App 版本检查改为 manifest.json 方式，支持多渠道发布
- 更新 settings 配置和测试用例适配新结构

apps/lib/features/settings/data/settings_api.dart

@@ -2,32 +2,41 @@ import 'package:social_app/core/api/i_api_client.dart';
 
 class AppVersionResponse {
   final bool hasUpdate;
-  final String latestVersion;
-  final int latestBuild;
-  final String minRequiredVersion;
+  final String latestVersionName;
+  final int latestVersionCode;
+  final int minSupportedVersionCode;
   final String updateType;
   final String? downloadUrl;
   final String? releaseNotes;
+  final String? fileName;
+  final int? fileSize;
+  final String? sha256;
 
   AppVersionResponse({
     required this.hasUpdate,
-    required this.latestVersion,
-    required this.latestBuild,
-    required this.minRequiredVersion,
+    required this.latestVersionName,
+    required this.latestVersionCode,
+    required this.minSupportedVersionCode,
     required this.updateType,
     this.downloadUrl,
     this.releaseNotes,
+    this.fileName,
+    this.fileSize,
+    this.sha256,
   });
 
   factory AppVersionResponse.fromJson(Map<String, dynamic> json) {
     return AppVersionResponse(
       hasUpdate: json['has_update'] as bool,
-      latestVersion: json['latest_version'] as String,
-      latestBuild: json['latest_build'] as int,
-      minRequiredVersion: json['min_required_version'] as String,
+      latestVersionName: json['latest_version_name'] as String,
+      latestVersionCode: json['latest_version_code'] as int,
+      minSupportedVersionCode: json['min_supported_version_code'] as int,
       updateType: json['update_type'] as String,
       downloadUrl: json['download_url'] as String?,
       releaseNotes: json['release_notes'] as String?,
+      fileName: json['file_name'] as String?,
+      fileSize: json['file_size'] as int?,
+      sha256: json['sha256'] as String?,
     );
   }
 }
@@ -39,20 +48,18 @@ class SettingsApi {
   SettingsApi(this._client);
 
   Future<AppVersionResponse> checkUpdates({
-    required int currentBuild,
-    String? currentVersion,
+    required int currentVersionCode,
+    required String currentVersionName,
     String platform = 'android',
+    String channel = 'release',
   }) async {
     final params = <String, String>{
       'platform': platform,
-      'current_build': currentBuild.toString(),
+      'channel': channel,
+      'current_version_code': currentVersionCode.toString(),
+      'current_version_name': currentVersionName,
     };
-    if (currentVersion != null) {
-      params['current_version'] = currentVersion;
-    }
-    final queryString = params.entries
-        .map((e) => '${e.key}=${e.value}')
-        .join('&');
+    final queryString = Uri(queryParameters: params).query;
     final response = await _client.get('$_prefix/check-updates?$queryString');
     return AppVersionResponse.fromJson(response.data);
   }