fix: 修复运行时配置递归与插件兼容入口

tests/test_configuration_ports.py

@@ -19,6 +19,7 @@ from app.application.configuration import (
     get_api_runtime_config_snapshot,
     get_transfer_retry_config,
 )
+from app.runtime.settings import RuntimeSettingsCompat, configure_runtime_settings_compat
 
 
 class _MutableSettings:
@@ -62,6 +63,16 @@ def test_runtime_settings_service_hides_mutable_settings_implementation() -> Non
     assert service.get("VALUE") == "final"
 
 
+def test_runtime_settings_compat_delegates_to_concrete_service_backend() -> None:
+    """兼容 Settings 代理委托到真实设置对象时不会在 model_dump 中递归。"""
+    service = RuntimeSettingsService(_MutableSettings())
+    configure_runtime_settings_compat(service)
+
+    assert RuntimeSettingsCompat().model_dump(include={"VALUE"}) == {
+        "VALUE": "before"
+    }
+
+
 def test_system_config_service_supports_separate_reader_and_writer() -> None:
     """应用服务可以分别注入只读与写入适配器。"""
     reader = MagicMock()