chore: update telegram docs

docs/usage/channels/telegram.mdx

@@ -82,6 +82,10 @@ To use the bot in Telegram groups:
 2. By default, the bot responds when mentioned with `@your_bot_username`
 3. Send a message mentioning the bot to start interacting
 
+<Callout type={'warning'}>
+  **About Group Privacy Mode:** Telegram bots have privacy mode enabled by default, which means they only receive messages that @mention the bot, reply to the bot, or contain /commands. If you change the privacy mode setting after creating the bot, you **must remove and re-add the bot to the group** for the new setting to take effect in that group.
+</Callout>
+
 ## Configuration Reference
 
 | Field                    | Required | Description                                    |
@@ -94,4 +98,4 @@ To use the bot in Telegram groups:
 
 - **Bot not responding:** Verify the bot token is correct and the configuration is saved. Click **Test Connection** to diagnose.
 - **Webhook registration failed:** Ensure your LobeHub subscription is active. Telegram requires HTTPS endpoints for webhooks, which LobeHub provides automatically.
-- **Group chat issues:** Make sure the bot has been added to the group and has permission to read messages. Mention the bot with `@username` to trigger a response.
+- **Group chat issues:** Make sure the bot has been added to the group and has permission to read messages. Mention the bot with `@username` to trigger a response. If the bot doesn't respond in a group, try removing the bot from the group and re-adding it — Telegram's privacy mode changes require re-joining the group to take effect.

docs/usage/channels/telegram.zh-CN.mdx

@@ -80,6 +80,10 @@ tags:
 2. 默认情况下，机器人在被 `@your_bot_username` 提及时会响应
 3. 发送一条提及机器人的消息以开始互动
 
+<Callout type={'warning'}>
+  **关于隐私模式（Group Privacy）：** Telegram 机器人默认启用隐私模式，仅接收群组中 @提及、回复机器人的消息以及 / 命令。如果您在创建机器人后更改了隐私模式设置，**必须将机器人从群组中移除后重新加入**，新的设置才会对该群组生效。
+</Callout>
+
 ## 配置参考
 
 | 字段               | 是否必需 | 描述                    |
@@ -92,4 +96,4 @@ tags:
 
 - **机器人未响应：** 验证机器人令牌是否正确并确保配置已保存。点击 **测试连接** 进行诊断。
 - **Webhook 注册失败：** 确保您的 LobeHub 订阅处于活动状态。Telegram 要求 Webhook 使用 HTTPS 端点，LobeHub 会自动提供。
-- **群组聊天问题：** 确保机器人已被添加到群组并具有读取消息的权限。使用 `@username` 提及机器人以触发响应。
+- **群组聊天问题：** 确保机器人已被添加到群组并具有读取消息的权限。使用 `@username` 提及机器人以触发响应。如果机器人在群组中没有响应，尝试将机器人从群组中移除后重新加入 ——Telegram 的隐私模式设置变更需要重新加入群组才能生效。