feat(chat-composer): show queue send button while working

[janburzinski]

Description

Replace the composer stop control with the send arrow when the agent is working and the user has entered a follow-up message or attached an image. Clicking the arrow uses the existing onSubmitWhileWorking path, so the follow-up is queued while the active turn continues.

The stop control remains available while the composer is empty.

Screenshot/Recording (if applicable)

Demo recording

Checklist

• I kept this PR small and focused
• I ran a self-review before opening this PR
• I ran the relevant local checks or explained why not
• Docs do not need updating for this UI-only behavior change
• Existing queue behavior is reused; manual coverage is included and the unrelated test failure is documented
• I only added comments where the logic is not obvious
• I used Conventional Commits for the commit message and PR title

[greptile-apps]

Greptile Summary

This PR shows a queue action when the composer has content during an active turn. The main changes are:

• Tracks the current editor text in composer state.
• Shows the send arrow for queueable text or image attachments while working.
• Routes the arrow through the existing queued-submit callback.
• Keeps the stop control visible when the composer is empty.

Confidence Score: 5/5

This looks safe to merge.

• The queue action requires a working-submit callback and queueable content.
• Text and image-only prompts follow the existing working-submit path.
• Editor mutations used by the current caller emit change events and keep the new state synchronized.
• No blocking issues were found in the changed code.

Important Files Changed

Filename	Overview
packages/ui/src/react/components/chat-composer/index.tsx	Tracks editor content and switches the working-state control between stopping and queueing.

_{Reviews (1): Last reviewed commit: "feat(chat-composer): show queue send but..." | Re-trigger Greptile}