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

src/renderer/extensions/vueNodes/preview/usePreviewStateProvider.ts

@@ -0,0 +1,14 @@
+import { computed, provide } from 'vue'
+
+import { NodePreviewImagesKey } from '@/renderer/core/canvas/injectionKeys'
+import { app } from '@/scripts/app'
+
+export const usePreviewStateProvider = () => {
+  // Provide reactive access to app.nodePreviewImages
+  // No need to duplicate data - app.nodePreviewImages is already reactive to changes
+  const nodePreviewImages = computed(() => app.nodePreviewImages)
+
+  provide(NodePreviewImagesKey, nodePreviewImages)
+
+  return { nodePreviewImages }
+}