fix(weixin): harden protocol delivery, streaming, and login (#5263)

nanobot/channels/base.py

@@ -101,6 +101,23 @@ class BaseChannel(ABC):
         """
         pass
 
+    def should_retry_send_error(self, error: Exception) -> bool:
+        """Return whether the channel manager may retry a failed delivery.
+
+        Channels with protocol-level business errors can override this hook to
+        prevent retries that cannot succeed until external state changes.
+        Transport and unexpected errors remain retryable by default.
+        """
+        return True
+
+    def start_error_message(self, error: Exception) -> str | None:
+        """Return an actionable public message for a channel startup failure.
+
+        Channel-specific exception handling stays in the owning channel. Returning
+        ``None`` keeps the manager's generic fallback.
+        """
+        return None
+
     async def send_delta(
         self,
         chat_id: str,