When a user sends a message inside a Feishu thread (话题) in a P2P
chat, the bot's reply was incorrectly sent outside the thread as a
standalone message. This was caused by PR openclaw#33789 which fixed group
reply targeting (openclaw#32980) but inadvertently broke P2P thread replies
by gating all thread-aware logic behind isGroup checks.

The fix distinguishes between two P2P scenarios based on the Feishu
API contract (thread_id present = thread message, root_id only =
quote reply):

- P2P thread messages (thread_id present): reply to root_id with
  reply_in_thread=true so the response stays in the thread.
- P2P plain replies (root_id only, no thread_id): reply to the
  triggering message as before.

Group chat behavior is completely unchanged — the new condition
(directThreadMessage) requires isDirect=true, which is always false
for groups.

Changes:
- replyInThread: true for P2P thread messages (enables reply_in_thread API flag)
- replyTargetMessageId: use root_id for P2P thread messages
- threadReply: true for P2P thread messages (drives effectiveReplyInThread in dispatcher)
- skipReplyToInMessages: false for P2P thread messages (so send layer
  uses im.message.reply instead of im.message.create)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>