Improve app service bot targeting and in-room action feedback

[tyreseluo]

Summary

This PR improves app service messaging behavior and bot visibility in room actions.

Changes

• Propagate target_user_id through RoomInputBar into MatrixRequest::SendMessage.
• Add reply-aware target resolution in input flow (prefers reply sender when explicit target is absent).
• Extend sliding sync send path to support targeted send:
  • inject org.octos.target_user_id into message content
  • ensure target bot is invited/joined before targeted send
  • handle both normal messages and replies
• Add View Bound Bots in App Service panel:
  • show bots from local bindings
  • include resolved parent bot
  • include likely bot members discovered in current room members
• Convert App Service action feedback from popup notifications to in-room notice messages (m.notice) to avoid triggering duplicate agent-style reply flows.

Why

• Prevent duplicate conversational replies caused by app-service status messages being treated as normal text.
• Make targeted routing to bot users explicit and reliable.
• Let users see all relevant bots in a room, not only the parent binding.

[tyreseluo]

Changes App service action show style in room.