Describe the bug

#2226 introduced generated open graph image, which is great

But it seems not to respect--dark

Maybe a parameters to add herehttps://github.com/slidevjs/slidev/pull/2226/files#diff-0bc6198e96130cfa918fcbbb6f5e1048bfeda180e015bc37f20cd6da376dea65R85

Minimal reproduction

Steps to reproduce the behavior:

1. Create a slide

2. Add front matter to generate open graph image

   seoMeta:ogImage:auto

3. Build slides :slidev build --dark

4. Look the generatedog-image.png which uses the light mode

Environment

• Slidev version: 52.1.0
• Browser: none, not needed to reproduce the bug
• OS: Linux 6.12.43, NixOS, 25.05 (Warbler), 25.05.20250826.4e7667a

If you are using Slidev globally (i.e.npx slidev ornpm i -g slidev), please try to reproduce the issue in a local project (i.e.npm create slidev@latest). I don't install it globally