refactor: DTO 字段去下划线 + SimApiBaseResponse 不再可继承 + 删除 SimApiJson/toJsonString

- 纯 POCO DTO 字段去下划线：AuthDto（id/name/applicationId/profileId/scene 等）、
  SimApiLoginItem（id/types/meta/extra）、AesBodyRequest（data）、
  SimApiBaseResponse 系列（code/message/data/list/page/count/total）
- SimApiBaseResponse 去 open（不再允许继承）+ 删 @SerializerParent（无子类继承）
- SimApiResponse<T> / SimApiDataResponse 改为组合（自带 code/message/data）
- 删除 toJsonString（无使用点，统一走 simapi_serialization）
- 删除 SimApiJson.cj：json() → SimApiUtil.json() 直接序列化；
  escapeJson() 迁入 SimApiUtil
- 同步更新所有字段引用（AuthCenter/AuthIam/HttpClient/ExceptionMiddleware 等）
- 保留 sqlsharp 实体 User/Bot 的 _ 前缀（soulsoft 宏依赖）

src/authsdk/SimApiAuthDto.cj

@@ -18,49 +18,49 @@ import std.collection.*
  * 应用/Profile 通用项（对齐 C# AppAndProfileItem）。
  */
 public class AppAndProfileItem {
-    public var _id: String = ""
-    public var _name: String = ""
-    public var _image: ?String = None
-    public var _description: ?String = None
+    public var id: String = ""
+    public var name: String = ""
+    public var image: ?String = None
+    public var description: ?String = None
 }
 
 /**
  * 安全确认响应（对齐 C# ConfirmResponse）。
- * _data 用 ?HashMap<String, Any> 对齐 C# Dictionary<string,object>?（任意 JSON 对象）。
+ * data 用 ?HashMap<String, Any> 对齐 C# Dictionary<string,object>?（任意 JSON 对象）。
  */
 public class ConfirmResponse {
-    public var _applicationId: String = ""
-    public var _profileId: String = ""
-    public var _scene: ?String = None
-    public var _data: ?HashMap<String, Any> = None
+    public var applicationId: String = ""
+    public var profileId: String = ""
+    public var scene: ?String = None
+    public var data: ?HashMap<String, Any> = None
 }
 
 /**
  * 登录信息响应（对齐 C# LoginInfoResponse）。
  */
 public class LoginInfoResponse {
-    public var _scene: ?String = None
-    public var _data: ?HashMap<String, Any> = None
-    public var _profileId: String = ""
-    public var _name: String = ""
-    public var _image: ?String = None
-    public var _description: ?String = None
+    public var scene: ?String = None
+    public var data: ?HashMap<String, Any> = None
+    public var profileId: String = ""
+    public var name: String = ""
+    public var image: ?String = None
+    public var description: ?String = None
 }
 
 /**
  * 获取授权码响应（对齐 C# GetCodeResponse）。
  */
 public class GetCodeResponse {
-    public var _code: String = ""
-    public var _server: String = ""
-    public var _fullUrl: String = ""
+    public var code: String = ""
+    public var server: String = ""
+    public var fullUrl: String = ""
 
     public init() {}
 
     public init(code: String, server: String, fullUrl: String) {
-        this._code = code
-        this._server = server
-        this._fullUrl = fullUrl
+        this.code = code
+        this.server = server
+        this.fullUrl = fullUrl
     }
 }
 
@@ -68,42 +68,42 @@ public class GetCodeResponse {
  * 群组关联项（对齐 C# GroupRelatedItem）。
  */
 public class GroupRelatedItem {
-    public var _id: String = ""
-    public var _name: String = ""
-    public var _image: ?String = None
-    public var _description: ?String = None
-    public var _isOwner: Bool = false
-    public var _isAdmin: Bool = false
-    public var _isMember: Bool = false
+    public var id: String = ""
+    public var name: String = ""
+    public var image: ?String = None
+    public var description: ?String = None
+    public var isOwner: Bool = false
+    public var isAdmin: Bool = false
+    public var isMember: Bool = false
 }
 
 /**
  * 群组详情树节点（对齐 C# GroupDetailTreeNode，children 递归）。
  */
 public class GroupDetailTreeNode {
-    public var _id: String = ""
-    public var _name: String = ""
-    public var _image: ?String = None
-    public var _description: ?String = None
-    public var _sort: Int64 = 0
-    public var _children: Array<GroupDetailTreeNode> = []
+    public var id: String = ""
+    public var name: String = ""
+    public var image: ?String = None
+    public var description: ?String = None
+    public var sort: Int64 = 0
+    public var children: Array<GroupDetailTreeNode> = []
 }
 
 /**
  * 权限项（对齐 C# PermissionItem）。
  */
 public class PermissionItem {
-    public var _identifier: String = ""
-    public var _name: String = ""
-    public var _group: String = ""
-    public var _description: String = ""
+    public var identifier: String = ""
+    public var name: String = ""
+    public var group: String = ""
+    public var description: String = ""
 
     public init() {}
 
     public init(identifier: String, name: String, group: String, description: String) {
-        this._identifier = identifier
-        this._name = name
-        this._group = group
-        this._description = description
+        this.identifier = identifier
+        this.name = name
+        this.group = group
+        this.description = description
     }
 }