refactor: 收口 V3 分层架构与插件兼容边界

app/application/plugin/runtime.py

@@ -0,0 +1,35 @@
+"""插件运行时目录的应用层端口。"""
+
+from __future__ import annotations
+
+from collections.abc import Callable
+from typing import Any, Protocol
+
+
+class PluginRuntime(Protocol):
+    """声明入口层消费的插件宿主能力。"""
+
+    def __getattr__(self, name: str) -> Any:
+        """允许兼容门面按既有 V3 方法名访问插件宿主能力。"""
+
+
+PluginRuntimeProvider = Callable[[], PluginRuntime]
+
+
+def _unconfigured_runtime() -> PluginRuntime:
+    """拒绝在启动组合根完成前隐式创建 Runtime 管理器。"""
+    raise RuntimeError("插件运行时尚未由启动组合根装配")
+
+
+_runtime_provider: PluginRuntimeProvider = _unconfigured_runtime
+
+
+def configure_plugin_runtime(provider: PluginRuntimeProvider) -> None:
+    """由启动组合根注册插件运行时实例提供器。"""
+    global _runtime_provider
+    _runtime_provider = provider
+
+
+def get_plugin_manager() -> PluginRuntime:
+    """返回当前组合根提供的插件运行时能力。"""
+    return _runtime_provider()