fix: 修复批量插件重载窗口期残留 handler 直调导致 missing event TypeError

插件重载 stop 阶段清除 sys.modules 缓存后，若广播事件命中注册表中残留的旧类方法声明，
EventBindingResolver.owner_class 因 inspect.getmodule 返回 None 而解析失败，原实现会
直接返回原始函数并绕过实例绑定，旧签名无 event 参数时抛出 TypeError 并刷屏通知。

- binding.py：owner_class 解析失败时区分类方法声明与自由函数；类方法声明记入
  unresolved 诊断并跳过执行，等待重载完成后新 handler 按标识覆盖自愈；
  自由函数保持直调路径不变。
- 收敛 binding-miss 与新路径的未命中记账逻辑到 _record_unresolved，首次未命中才告警。
- 新增回归测试：模块卸载后残留类方法被跳过、自由函数直调不受影响。

Closes #6351

app/runtime/event/binding.py

@@ -57,6 +57,12 @@ class EventBindingResolver:
             return "", names[0]
         return names[0], names[1]
 
+    @staticmethod
+    def is_class_method_declaration(handler: Callable) -> bool:
+        """判断处理器是否声明在类体内（限定名含类前缀且非局部闭包）。"""
+        parts = handler.__qualname__.split(".")
+        return len(parts) >= 2 and "<locals>" not in parts
+
     @staticmethod
     def owner_class(handler: Callable) -> Optional[Type[Any]]:
         """从处理器对象本身解析声明类，不按字符串动态导入模块。"""
@@ -75,6 +81,14 @@ class EventBindingResolver:
                 return None
         return owner if isinstance(owner, type) else None
 
+    def _record_unresolved(self, identifier: str, reason: str) -> None:
+        """首次未命中时记录告警，避免重载窗口内重复刷屏。"""
+        with self._lock:
+            first_miss = identifier not in self._unresolved
+            self._unresolved.add(identifier)
+        if first_miss:
+            logger.warning(reason, identifier)
+
     def resolve(
         self,
         handler: Callable,
@@ -87,6 +101,15 @@ class EventBindingResolver:
             self.parse_handler_names(handler)[1],
         )
         if owner_class is None:
+            # 插件重载会先清除模块缓存，窗口期内残留的旧类方法声明无法定位声明类；
+            # 此时直接调用原始函数会绕过实例绑定（旧签名可能与事件调用约定不一致），
+            # 因此按未绑定处理跳过，等待重载完成后按新 handler 注册自愈。
+            if self.is_class_method_declaration(handler):
+                self._record_unresolved(
+                    EventRegistry.handler_identifier(handler),
+                    "事件处理器所属模块已卸载或声明类不可解析，跳过执行：%s",
+                )
+                return None
             binding = EventHandlerBinding(
                 instance=None,
                 owner_name=EventRegistry.handler_identifier(handler),
@@ -105,15 +128,10 @@ class EventBindingResolver:
                 resolver_name = name
                 break
         if binding is None:
-            identifier = EventRegistry.handler_identifier(handler)
-            with self._lock:
-                first_miss = identifier not in self._unresolved
-                self._unresolved.add(identifier)
-            if first_miss:
-                logger.warning(
-                    "事件处理器未绑定显式 resolver，已跳过：%s",
-                    identifier,
-                )
+            self._record_unresolved(
+                EventRegistry.handler_identifier(handler),
+                "事件处理器未绑定显式 resolver，已跳过：%s",
+            )
             return None
         logger.debug(
             "事件处理器绑定：%s -> %s",

tests/test_event_runtime_components.py

@@ -1,6 +1,8 @@
 """事件注册、绑定、调度和错误策略组件的独立测试。"""
 
+import sys
 import threading
+import types
 from unittest.mock import Mock
 
 from app.runtime.event.binding import (
@@ -26,6 +28,10 @@ class _UnmanagedHandler:
         """提供可解析的实例方法声明。"""
 
 
+def _free_function_handler(_event: Event) -> None:
+    """模块级自由函数处理器，用于验证直调路径保持不变。"""
+
+
 def test_binding_miss_does_not_construct_handler_owner() -> None:
     """resolver 未命中时只记录诊断，不能调用 owner_class()。"""
     resolvers = {}
@@ -42,6 +48,53 @@ def test_binding_miss_does_not_construct_handler_owner() -> None:
     )
 
 
+def test_unloaded_module_class_handler_is_skipped() -> None:
+    """模块缓存被清除后，残留的类方法声明必须跳过而非直调原始函数。"""
+    fake_name = "tests._fake_unloaded_plugin"
+    fake_module = types.ModuleType(fake_name)
+    sys.modules[fake_name] = fake_module
+    try:
+        # 在伪模块命名空间内构造类，使处理器 __module__ 指向该模块
+        exec(
+            "class _ResidualPlugin:\n"
+            "    def reload(self, event):\n"
+            "        raise AssertionError('residual handler must not run')\n",
+            fake_module.__dict__,
+        )
+        residual_handler = fake_module._ResidualPlugin.reload
+        # 模拟插件重载 stop 阶段清除模块缓存后的残留注册
+        del sys.modules[fake_name]
+
+        binding = EventBindingResolver(
+            lock=threading.Lock(),
+            resolvers=lambda: {},
+        )
+        assert binding.resolve(residual_handler) is None
+        # 模块卸载后 identifier 回退为 unknown_module 前缀，与线上日志一致
+        assert binding.unresolved_handlers() == (
+            "unknown_module._ResidualPlugin.reload",
+        )
+    finally:
+        sys.modules.pop(fake_name, None)
+
+
+def test_free_function_handler_still_invoked_directly() -> None:
+    """自由函数处理器不属于类声明，保持直调路径不被新跳过逻辑影响。"""
+    binding = EventBindingResolver(
+        lock=threading.Lock(),
+        resolvers=lambda: {},
+    )
+
+    resolved = binding.resolve(_free_function_handler)
+
+    assert resolved is not None
+    method, handler_binding, class_name, method_name = resolved
+    assert method is _free_function_handler
+    assert handler_binding.run_sync_in_threadpool is True
+    assert class_name == ""
+    assert method_name == "_free_function_handler"
+
+
 def test_binding_uses_explicit_resolver_instance() -> None:
     """显式 resolver 应返回当前托管实例上的绑定方法。"""
     instance = object.__new__(_UnmanagedHandler)