fix(ui): align Ask mode in new issue modal

[janburzinski]

Description

Align the Ask permission-mode control in the new issue modal when no model or agent selector precedes it. This removes the empty model placeholder and gives the first permission trigger balanced horizontal padding, so its icon aligns with the prompt input while the hover surface remains visually centered.

Related issues

Linear: ENG-1837

Screenshot/Recording (if applicable)

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
• I updated docs when behavior or setup changed
• I added or updated tests when behavior changed, or explained why not
• I only added comments where the logic is not obvious
• I used Conventional Commits for commit messages and, when possible, the PR title

[greptile-apps]

Greptile Summary

This PR adjusts the ChatComposer toolbar layout for the new issue modal.

• Removes the empty model placeholder when no model selector is shown.
• Adds first-position padding for the permission-mode trigger.
• Applies that padding only when no model or agent selector appears before it.

Confidence Score: 5/5

This looks safe to merge.

• No blocking issues found in the changed code.

Important Files Changed

Filename	Overview
packages/ui/src/react/components/chat-composer/chat-composer.css.ts	Adds a focused padding style for the first permission-mode trigger.
packages/ui/src/react/components/chat-composer/index.tsx	Updates ChatComposer rendering so the permission-mode trigger can become the first toolbar control.

_{Reviews (1): Last reviewed commit: "fix(ui): align Ask mode in new issue mod..." | Re-trigger Greptile}

[arnestrickmann]

thanks for catching this!