fix: show trigger action after markdown finishes typing

[kiannidev]

Fixes #1405.

Summary

• Ensure the “Add trigger action” card (TaskCompletionCard) only appears after the assistant’s final END message has fully finished streaming/typing.
• Add a per-query isCompletionReady flag in UserQueryGroup that is set only when the END AgentMessageCard’s typewriter completes.
• Gate TaskCompletionCard rendering on both task.status === 'finished' and isCompletionReady, so the UI no longer shows trigger actions while the markdown answer is still typing.

Implementation details

• Updated src/components/ChatBox/UserQueryGroup.tsx:
  • Track isCompletionReady with local state and reset when the active task or query group changes.
  • Pass onTyping to the END AgentMessageCard to set isCompletionReady when its MarkDown typewriter finishes.
  • Render TaskCompletionCard only when task.status === 'finished' && isCompletionReady.

Testing

• Started a new project and submitted a task that produces a multi-line, streaming markdown answer.
• Verified that:
  • During streaming, the “Add trigger action” card does not appear.
  • As soon as the END message finishes typing, the “Add trigger action” card appears below the final answer.
• Replayed an existing project and confirmed the same behavior holds for replayed conversations.

[4pmtong]

LGTM. Thanks @kiannidev for contribution

[a7m-1st]

Thanks @kiannidev & @4pmtong !