[feat] Improve queue job item UX based on design feedback (#6893)

## Summary
- Running jobs now show cancel button at all times (always visible, not
just on hover)
- Cancel/delete buttons use destructive red styling by default with
hover state
- Changed pending job icon from clock to loader-circle with spin
animation
- Fixed icon buttons to be square (size-6) instead of rectangular
- Added TODO comment for future declarative button config system
- Pending hint ("Job added to queue") now shows only once per entry and
no longer resets when other jobs update
- Spinner animation now applies only to the pending loader icon;
completed/check icons no longer spin
- Queue overlay hover/active state also triggers when hovering the top
menu bar so controls stay visible

## Design Spec

https://www.notion.so/comfy-org/Design-Queue-Dialog-Job-Ordering-and-Cancel-Button-Visibility-2b46d73d365081748a43d5cc9fbe2639

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6893-feat-Improve-queue-job-item-UX-based-on-design-feedback-2b56d73d365081a2bc7ef6f6fea1c739)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Claude <noreply@anthropic.com>

src/utils/queueDisplay.ts

@@ -24,7 +24,7 @@ type JobDisplay = {
 export const iconForJobState = (state: JobState): string => {
   switch (state) {
     case 'pending':
-      return 'icon-[lucide--clock]'
+      return 'icon-[lucide--loader-circle]'
     case 'initialization':
       return 'icon-[lucide--server-crash]'
     case 'running':