fix: vue nodes image preview widget, better multi image gallery support (#7178)

## Summary

Fix image preview to better handle multiple images, switching between
them, and showing the skeleton correctly.

## Changes

- **What**: ImagePreview.vue

## Screenshots (if applicable)

Old (broken)


https://github.com/user-attachments/assets/e4997569-bdf5-4015-a83c-bbaabeac96d6

New (fixed)


https://github.com/user-attachments/assets/19dda841-c909-4fcb-b4d4-99aa1372843b

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7178-fix-vue-nodes-image-preview-widget-better-multi-image-gallery-support-2c06d73d365081a2afa9e398200e8379)
by [Unito](https://www.unito.io)

---------

Co-authored-by: github-actions <github-actions@github.com>

tests-ui/tests/renderer/extensions/vueNodes/components/ImagePreview.test.ts

@@ -225,16 +225,16 @@ describe('ImagePreview', () => {
     const navigationDots = wrapper.findAll('.w-2.h-2.rounded-full')
 
     // First dot should be active (has bg-white class)
-    expect(navigationDots[0].classes()).toContain('bg-white')
-    expect(navigationDots[1].classes()).toContain('bg-white/50')
+    expect(navigationDots[0].classes()).toContain('bg-base-foreground')
+    expect(navigationDots[1].classes()).toContain('bg-base-foreground/50')
 
     // Switch to second image
     await navigationDots[1].trigger('click')
     await nextTick()
 
     // Second dot should now be active
-    expect(navigationDots[0].classes()).toContain('bg-white/50')
-    expect(navigationDots[1].classes()).toContain('bg-white')
+    expect(navigationDots[0].classes()).toContain('bg-base-foreground/50')
+    expect(navigationDots[1].classes()).toContain('bg-base-foreground')
   })
 
   it('loads image without errors', async () => {