refactor(schemas): 统一 message/notification 命名边界，旧名收敛至兼容映射表

- notification 域：渠道能力（MessageChannel→NotificationChannel、ChannelCapability* 迁入 notification.py）
- message 域：消息收发（Notification→Message、NotificationType→MessageType、CommingMessage→IncomingMessage、NotificationHistoryItem→MessageHistoryItem、NotificationClear*→MessageClear*）
- Agent 工具契约：send_notification_message→send_message、notification_callback→message_callback
- 源码不保留旧名物理别名，旧导入经 app/runtime/compat/manifest.py SYMBOL_ALIASES 惰性解析
- API 路径与持久化键冻结不变，前端零改动
- 新增兼容守护测试与 docs/rules/07 命名边界规范

app/modules/__init__.py

@@ -5,8 +5,8 @@ from pathlib import Path
 
 from app.runtime.extensions.service_registry import ServiceConfigHelper
 from app.runtime.log import logger
-from app.schemas import Notification, NotificationConf, MediaServerConf, DownloaderConf
-from app.schemas.types import ModuleType, DownloaderType, MediaServerType, MessageChannel, StorageSchema, \
+from app.schemas import Message, NotificationConf, MediaServerConf, DownloaderConf
+from app.schemas.types import ModuleType, DownloaderType, MediaServerType, NotificationChannel, StorageSchema, \
     OtherModulesType, SystemConfigKey, MediaRecognizeType
 from app.runtime.reload import ConfigReloadMixin
 
@@ -69,7 +69,7 @@ class _ModuleBase(ConfigReloadMixin, metaclass=ABCMeta):
     def get_subtype() -> Union[
         DownloaderType,
         MediaServerType,
-        MessageChannel,
+        NotificationChannel,
         StorageSchema,
         OtherModulesType,
         MediaRecognizeType,
@@ -214,7 +214,7 @@ class _MessageBase(ServiceBase[TService, NotificationConf]):
         初始化消息基类，并设置消息通道
         """
         super().__init__()
-        self._channel: Optional[MessageChannel] = None
+        self._channel: Optional[NotificationChannel] = None
 
     def get_configs(self) -> Dict[str, NotificationConf]:
         """
@@ -227,7 +227,7 @@ class _MessageBase(ServiceBase[TService, NotificationConf]):
             return {}
         return {conf.name: conf for conf in configs if conf.type == self._service_name and conf.enabled}
 
-    def check_message(self, message: Notification, source: str = None) -> bool:
+    def check_message(self, message: Message, source: str = None) -> bool:
         """
         检查消息渠道及消息类型，判断是否处理消息