refactor: 全框架 JSON 操作迁移到 simapi_serialization

- 依赖：新增 simapi_serialization path 依赖（保留 soulsoft_serialization 供 soulsoft web 栈传递使用）
- SimApiJson.json / SimApiUtil.json → JsonSerializer.Serialize
- SimApiUtil.fromJson / base64DecodeTo → JsonSerializer.Deserialize（去 ISerialization 约束）
- SimApiHttpClient signQuery/aesQuery/aesSignQuery/query → 去约束，反序列化换新库
- SimApiBaseResponse/SimApiDataResponse/SimApiLoginItem/AesBodyRequest/AuthSDK DTO → 去 @Serialization 宏/去 soulsoft 接口，改纯 POCO（simapi_serialization 反射）
- SimApiBaseResponse 标 @SerializerParent：子类响应序列化包含 _code/_message
- SimApiResultWriter / SimApiExceptionMiddleware → 响应输出走 simapi_serialization（统一 _code/_message 格式）
- SimApiRequestLogMiddleware 截断 → Deserialize<HashMap<String,Any>> + 重序列化
- SimApiAuthDto JsonValue 字段 → HashMap<String,Any>；SimApiCache.get<T> 去约束
- webdemo：AuthController readFromJson 换 Deserialize；cjpm.toml 补依赖
- 验证：webdemo 启动正常，GET/POST 接口响应格式统一，S3 存储全链路 OK

src/middlewares/SimApiExceptionMiddleware.cj

@@ -7,6 +7,7 @@ package simapi.middlewares
 
 import soulsoft_web_http.*
 import soulsoft_extensions_logging.*
+import simapi_serialization.*
 import simapi.communications.*
 import simapi.exceptions.*
 import simapi.configurations.*
@@ -60,7 +61,7 @@ public class SimApiExceptionMiddleware <: IMiddleware {
             }
             var response = SimApiBaseResponse(simEx.code, message)
             if (context.response.statusCode == 404) {
-                response.message = "接口不存在"
+                response._message = "接口不存在"
             }
             return response
         }
@@ -69,6 +70,6 @@ public class SimApiExceptionMiddleware <: IMiddleware {
     }
 
     private func responseJson(response: SimApiBaseResponse): String {
-        response.toJsonString()
+        JsonSerializer.Serialize(response)
     }
 }