Show sampling previews on Vue nodes (#5579)

* refactor: simplify preview state provider

- Remove unnecessary event listeners and manual syncing
- Use computed() to directly reference app.nodePreviewImages
- Eliminate data duplication and any types
- Rely on Vue's reactivity for automatic updates
- Follow established patterns from execution state provider

* feat: optimize Vue node preview image display with reactive store

- Move preview display logic from inline ternaries to computed properties
- Add useNodePreviewState composable for preview state management
- Implement reactive store approach using Pinia storeToRefs
- Use VueUse useTimeoutFn for modern timeout management instead of window.setTimeout
- Add v-memo optimization for preview image template rendering
- Maintain proper sync between app.nodePreviewImages and reactive store state

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

* fix: update props usage for Vue 3.5 destructured props syntax

* [refactor] improve code style and architecture based on review feedback

- Replace inject pattern with direct store access in useNodePreviewState
- Use optional chaining for more concise conditional checks
- Use modern Array.at(-1) for accessing last element
- Remove provide/inject for nodePreviewImages in favor of direct store refs
- Update preview image styling: remove rounded borders, use flexible height
- Simplify scheduleRevoke function with optional chaining

Co-authored-by: DrJKL <DrJKL@users.noreply.github.com>

* [cleanup] remove unused NodePreviewImagesKey injection key

Addresses knip unused export warning after switching from provide/inject
to direct store access pattern.

* [test] add mock for useNodePreviewState in LGraphNode test

Fixes test failure after adding preview functionality to LGraphNode component.

* [fix] update workflowStore import path after rebase

Updates import to new location: @/platform/workflow/management/stores/workflowStore

---------

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

tests-ui/tests/renderer/extensions/vueNodes/components/LGraphNode.spec.ts

@@ -56,6 +56,13 @@ vi.mock(
   })
 )
 
+vi.mock('@/renderer/extensions/vueNodes/preview/useNodePreviewState', () => ({
+  useNodePreviewState: vi.fn(() => ({
+    latestPreviewUrl: computed(() => ''),
+    shouldShowPreviewImg: computed(() => false)
+  }))
+}))
+
 const i18n = createI18n({
   legacy: false,
   locale: 'en',