[feat] Show context-appropriate empty state messages in Manager tabs (#8415)

## Summary
Shows tab-specific empty state messages in Node Manager instead of
generic "No search results found" message.

## Changes
- Added computed properties to determine empty state messages based on
current tab and search state
- Display tab-specific messages when a tab is empty without active
search (e.g., "No Missing Nodes" for Missing tab)
- Fall back to search-related messages only when there's an active
search query
- Added Korean translations for empty state messages

| Tab | Empty State Title |
|-----|-------------------|
| All Installed | No Extensions Installed |
| Update Available | All Up to Date |
| Conflicting | No Conflicts Detected |
| Workflow | No Extensions in Workflow |
| Missing | No Missing Nodes |

## Review Focus
- Verify i18n key structure matches existing patterns

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8415-feat-Show-context-appropriate-empty-state-messages-in-Manager-tabs-2f76d73d3650817ab8a0d41b45df3411)
by [Unito](https://www.unito.io)

src/workbench/extensions/manager/components/manager/ManagerDialog.vue

@@ -130,16 +130,8 @@
       </div>
       <NoResultsPlaceholder
         v-else-if="displayPacks.length === 0"
-        :title="
-          comfyManagerStore.error
-            ? $t('manager.errorConnecting')
-            : $t('manager.noResultsFound')
-        "
-        :message="
-          comfyManagerStore.error
-            ? $t('manager.tryAgainLater')
-            : $t('manager.tryDifferentSearch')
-        "
+        :title="emptyStateTitle"
+        :message="emptyStateMessage"
       />
       <div v-else class="h-full w-full" @click="handleGridContainerClick">
         <VirtualGrid
@@ -398,6 +390,40 @@ const isMissingTab = computed(
   () => selectedTab.value?.id === ManagerTab.Missing
 )
 
+// Map of tab IDs to their empty state i18n key suffixes
+const tabEmptyStateKeys: Partial<Record<ManagerTab, string>> = {
+  [ManagerTab.AllInstalled]: 'allInstalled',
+  [ManagerTab.UpdateAvailable]: 'updateAvailable',
+  [ManagerTab.Conflicting]: 'conflicting',
+  [ManagerTab.Workflow]: 'workflow',
+  [ManagerTab.Missing]: 'missing'
+}
+
+// Empty state messages based on current tab and search state
+const emptyStateTitle = computed(() => {
+  if (comfyManagerStore.error) return t('manager.errorConnecting')
+  if (searchQuery.value) return t('manager.noResultsFound')
+
+  const tabId = selectedTab.value?.id as ManagerTab | undefined
+  const emptyStateKey = tabId ? tabEmptyStateKeys[tabId] : undefined
+
+  return emptyStateKey
+    ? t(`manager.emptyState.${emptyStateKey}.title`)
+    : t('manager.noResultsFound')
+})
+
+const emptyStateMessage = computed(() => {
+  if (comfyManagerStore.error) return t('manager.tryAgainLater')
+  if (searchQuery.value) return t('manager.tryDifferentSearch')
+
+  const tabId = selectedTab.value?.id as ManagerTab | undefined
+  const emptyStateKey = tabId ? tabEmptyStateKeys[tabId] : undefined
+
+  return emptyStateKey
+    ? t(`manager.emptyState.${emptyStateKey}.message`)
+    : t('manager.tryDifferentSearch')
+})
+
 const onClickWarningLink = () => {
   window.open(
     buildDocsUrl('/troubleshooting/custom-node-issues', {