Scope queued follow-up tooltips to each control

[ywenhao]

Summary

• Queued follow-up rows put Edit in composer on the whole row, so Steer/Remove flashed that hint first and More kept showing it.
• Scope that tooltip to the text hit target (same as the web composer) and give More composer.queued_message_actions.

Fixes #173

Test plan

• Queue a follow-up while a turn is running so the card appears above the composer
• Hover the message text → Edit in composer
• Hover Steer → Steer current turn, with no flash of Edit in composer
• Hover Remove → Remove from queue
• Hover More → Follow-up actions (zh-CN: 后续消息操作)
• Clicking the text still pulls the message into the composer; Steer/Remove/More still work; Enter/Space on the text region still edits