feat(home): 添加 miUserId 字段以支持 IM 系统用户标识

- 在 UserInfoData 模型中新增 miUserId 属性
- 更新模型序列化逻辑以包含 miUserId 字段
- 简化用户信息页面中的目标用户 ID 获取逻辑，直接使用 miUserId
- 移除原有的多层级用户 ID 查找逻辑，提高代码可读性

lib/model/home/user_info_data.dart

@@ -5,6 +5,7 @@ class UserInfoData {
   String? updateTime;
   Null? event;
   String? accountId;
+  String? miUserId;
   String? userId;
   String? nickName;
   String? name;
@@ -150,6 +151,7 @@ class UserInfoData {
         this.accountTypeName,
         this.nationalityCode,
         this.nationality,
+        this.miUserId,
         this.nativePlaceCode,
         this.nativePlaceName,
         this.industryCode,
@@ -200,6 +202,7 @@ class UserInfoData {
     userId = json['userId'];
     nickName = json['nickName'];
     name = json['name'];
+    miUserId = json['miUserId'];
     profilePhoto = json['profilePhoto'];
     hasUploadProfilePhoto = json['hasUploadProfilePhoto'];
     photoDisplay = json['photoDisplay'];
@@ -310,6 +313,7 @@ class UserInfoData {
     data['userId'] = this.userId;
     data['nickName'] = this.nickName;
     data['name'] = this.name;
+    data['miUserId'] = this.miUserId;
     data['profilePhoto'] = this.profilePhoto;
     data['hasUploadProfilePhoto'] = this.hasUploadProfilePhoto;
     data['photoDisplay'] = this.photoDisplay;

lib/pages/home/user_information_page.dart

@@ -462,11 +462,7 @@ class UserInformationPage extends StatelessWidget {
                           
                           // IM系统需要使用userId或accountId，而不是miId
                           // 优先使用userId（这是IM系统的用户ID），如果没有则使用accountId，最后才使用miId
-                          String? targetUserId = (userInfo.userId?.isNotEmpty == true ? userInfo.userId : 
-                                                  (userInfo.accountId?.isNotEmpty == true ? userInfo.accountId : 
-                                                  (userInfo.miId?.isNotEmpty == true ? userInfo.miId : 
-                                                  (userInfo.id?.isNotEmpty == true ? userInfo.id : 
-                                                  (miId.isNotEmpty ? miId : null)))));
+                          String? targetUserId = userInfo.miUserId;
                           
                           if (targetUserId == null || targetUserId.isEmpty) {
                             print('❌ [UserInformationPage] 无法获取用户ID，无法跳转');