feat(chat): 增强回复功能，支持通过字符串指定并显示用户ID

为了让插件能更灵活地构造回复消息，而无需依赖完整的原始消息对象，本次提交引入了新的回复机制。

- `send_api` 新增 `reply_to` 参数，允许使用 `昵称(ID)` 格式的字符串直接指定回复目标。
- 统一更新了回复消息的显示格式，在回复引文中一并展示用户昵称和ID，避免因昵称重复造成混淆。

src/plugin_system/apis/send_api.py

@@ -244,12 +244,34 @@ async def _send_to_target(
         message_segment = Seg(type=message_type, data=content)  # type: ignore
 
         # 处理回复消息
-        if reply_to_message:
+        if reply_to:
+            # 优先使用 reply_to 字符串构建 anchor_message
+            # 解析 "发送者(ID)" 格式
+            import re
+            match = re.match(r"(.+)\((\d+)\)", reply_to)
+            if match:
+                sender_name, sender_id = match.groups()
+                temp_message_dict = {
+                    "user_nickname": sender_name,
+                    "user_id": sender_id,
+                    "chat_info_platform": target_stream.platform,
+                    "message_id": "temp_reply_id", # 临时ID
+                    "time": time.time()
+                }
+                anchor_message = message_dict_to_message_recv(message_dict=temp_message_dict)
+            else:
+                 anchor_message = None
+            reply_to_platform_id = f"{target_stream.platform}:{sender_id}" if anchor_message else None
+
+        elif reply_to_message:
             anchor_message = message_dict_to_message_recv(message_dict=reply_to_message)
-            anchor_message.update_chat_stream(target_stream)
-            reply_to_platform_id = (
-                f"{anchor_message.message_info.platform}:{anchor_message.message_info.user_info.user_id}"
-            )
+            if anchor_message:
+                anchor_message.update_chat_stream(target_stream)
+                reply_to_platform_id = (
+                    f"{anchor_message.message_info.platform}:{anchor_message.message_info.user_info.user_id}"
+                )
+            else:
+                reply_to_platform_id = None
         else:
             anchor_message = None
             reply_to_platform_id = None