feat(dingtalk): add support for group chat messages

nanobot/channels/dingtalk.py

@@ -70,6 +70,13 @@ class NanobotDingTalkHandler(CallbackHandler):
             sender_id = chatbot_msg.sender_staff_id or chatbot_msg.sender_id
             sender_name = chatbot_msg.sender_nick or "Unknown"
 
+            # Extract conversation info
+            conversation_type = message.data.get("conversationType")
+            conversation_id = message.data.get("conversationId") or message.data.get("openConversationId")
+
+            if conversation_type == "2" and conversation_id:
+                sender_id = f"group:{conversation_id}"
+
             logger.info("Received DingTalk message from {} ({}): {}", sender_name, sender_id, content)
 
             # Forward to Nanobot via _on_message (non-blocking).
@@ -301,8 +308,19 @@ class DingTalkChannel(BaseChannel):
             logger.warning("DingTalk HTTP client not initialized, cannot send")
             return False
 
-        url = "https://api.dingtalk.com/v1.0/robot/oToMessages/batchSend"
         headers = {"x-acs-dingtalk-access-token": token}
+        if chat_id.startswith("group:"):
+            # Group chat
+            url = "https://api.dingtalk.com/v1.0/robot/groupMessages/send"
+            payload = {
+                "robotCode": self.config.client_id,
+                "openConversationId": chat_id[6:],  # Remove "group:" prefix,
+                "msgKey": "sampleMarkdown",
+                "msgParam": json.dumps(msg_param, ensure_ascii=False),
+            }
+        else:
+            # Private chat
+            url = "https://api.dingtalk.com/v1.0/robot/oToMessages/batchSend"
             payload = {
                 "robotCode": self.config.client_id,
                 "userIds": [chat_id],