[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/composables/queue/useJobList.ts

@@ -96,6 +96,7 @@ export function useJobList() {
   const executionStore = useExecutionStore()
   const workflowStore = useWorkflowStore()
 
+  const seenPendingIds = ref<Set<string>>(new Set())
   const recentlyAddedPendingIds = ref<Set<string>>(new Set())
   const addedHintTimeouts = new Map<string, ReturnType<typeof setTimeout>>()
 
@@ -126,23 +127,27 @@ export function useJobList() {
         .filter((id): id is string => !!id),
     (pendingIds) => {
       const pendingSet = new Set(pendingIds)
-      const next = new Set(recentlyAddedPendingIds.value)
+      const nextAdded = new Set(recentlyAddedPendingIds.value)
+      const nextSeen = new Set(seenPendingIds.value)
 
       pendingIds.forEach((id) => {
-        if (!next.has(id)) {
-          next.add(id)
+        if (!nextSeen.has(id)) {
+          nextSeen.add(id)
+          nextAdded.add(id)
           scheduleAddedHintExpiry(id)
         }
       })
 
-      for (const id of Array.from(next)) {
+      for (const id of Array.from(nextSeen)) {
         if (!pendingSet.has(id)) {
-          next.delete(id)
+          nextSeen.delete(id)
+          nextAdded.delete(id)
           clearAddedHintTimeout(id)
         }
       }
 
-      recentlyAddedPendingIds.value = next
+      recentlyAddedPendingIds.value = nextAdded
+      seenPendingIds.value = nextSeen
     },
     { immediate: true }
   )
@@ -157,6 +162,7 @@ export function useJobList() {
   onUnmounted(() => {
     addedHintTimeouts.forEach((timeoutId) => clearTimeout(timeoutId))
     addedHintTimeouts.clear()
+    seenPendingIds.value = new Set<string>()
     recentlyAddedPendingIds.value = new Set<string>()
   })