fix(tasks): keep conversation modal closable

[janburzinski]

Description

• fixes modal getting stuck during "creating...", where you couldnt close it anymore after it got stuck

Screenshot/Recording (if applicable)

https://streamable.com/cvct8r (i removed that cancel button from the video lol)

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 updates the create conversation modal so it can be closed while creation is pending.

• Removes the modal close guard during submission.
• Skips stale success and error updates when the active modal has changed.
• Marks the create button as a plain button.

Confidence Score: 4/5

This is close, but the pending create flow should be fixed before merging.

• Closing the modal now skips stale UI callbacks.
• The create request can still finish and persist a conversation after the modal was dismissed.
• The remaining issue is limited to the create conversation modal flow.

apps/emdash-desktop/src/renderer/features/tasks/conversations/create-conversation-modal.tsx

Important Files Changed

Filename	Overview
apps/emdash-desktop/src/renderer/features/tasks/conversations/create-conversation-modal.tsx	Updates modal close behavior and stale callback handling, but the create request can still complete after dismissal.

Prompt To Fix All With AI

Fix the following 1 code review issue. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 1
apps/emdash-desktop/src/renderer/features/tasks/conversations/create-conversation-modal.tsx:85
**Create still completes** This guard only runs after `createConversation` has already returned a new conversation id. When the user closes the modal while the request is still pending, the stale `onSuccess` call is skipped, but the RPC has already created the conversation before this line runs. That means a dismissed create flow can still leave a new conversation in stored data or later refreshed lists. The close path needs either cancellation or a cleanup/ignore mechanism at the create result boundary, not only a skipped success callback.

_{Reviews (2): Last reviewed commit: "fix(tasks): ignore dismissed conversatio..." | Re-trigger Greptile}

[janburzinski]

@greptileai