Issue: Bot replies create new topics instead of replying under the original topic in Feishu topic groups

Description

In Feishu/Lark topic groups (话题群), when a user mentions the bot within an existing topic thread, the bot's reply creates a new standalone topic instead of appearing as a comment under the original topic.

Steps to Reproduce

1. Add the bot to a Feishu topic group (话题群)
2. Create a new topic or navigate to an existing topic
3. @mention the bot within that topic thread
4. Observe that the bot's response appears as a new topic, not under the original topic

Expected Behavior

The bot's reply should appear as a comment under the original topic where it was mentioned.

Actual Behavior

The bot creates a new topic with its reply, causing the conversation to be fragmented.

Root Cause Analysis

In extensions/feishu/src/bot.ts, the bot uses ctx.messageId as the replyToMessageId when creating reply dispatchers. However, in topic groups:

• Messages have a root_id field identifying the topic's root message
• The Feishu API requires targeting the root message ID to reply within a topic
• Using the specific message ID triggers the creation of a new topic

Proposed Solution

Change the reply target from ctx.messageId to ctx.rootId ?? ctx.messageId in both reply dispatcher calls:

• Line ~850: Permission error notification dispatcher
• Line ~935: Normal reply dispatcher

This ensures replies target the topic root when in a topic, falling back to normal behavior otherwise.

Environment

• OpenClaw version: 2026.2.17
• Feishu extension: @openclaw/feishu

Additional Context

Topic groups are a special group type in Feishu where conversations are organized as threads (topics) rather than a linear message stream. Proper handling of root_id is essential for correct reply behavior in this context.