fix: use absolute url for og:image tag

[Balastrong]

Sharing https://tanstack.com/ in social networks (like linkedin) does not properly show the og:image in the preview.

See images

Our current value is /_build/assets/og-pGgYlhyc.png but it seems only absolute urls are valid.

I'm not sure this works as I cannot reliably test it locally but I'd probably give it a try.
I think other pages may be affected but let's do it step by step (or if anyone has a better solution is welcome!)

[vercel]

@Balastrong is attempting to deploy a commit to the Tanstack Team on Vercel.

A member of the Team first needs to authorize it.

[SeanCassiere]

On second though, maybe we should be using one of Vercel's publish URL environment variables?
https://vercel.com/docs/projects/environment-variables/framework-environment-variables

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Comments	Updated (UTC)
tanstack-com	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Sep 16, 2024 2:07pm

[Balastrong]

On second though, maybe we should be using one of Vercel's publish URL environment variables? https://vercel.com/docs/projects/environment-variables/framework-environment-variables

Agree, that would be probably more correct!
I didn't find any of those used in the codebase so I went with the hardcoded url to at least validate the fix.

Side note, do we even have those variable available? I mean NEXT_XXX while we're on a TanStack Start project.

[SeanCassiere]

Side note, do we even have those variable available? I mean NEXT_XXX while we're on a TanStack Start project.

Since Start uses Vinxi, you should be able to use the same variables used for SolidStart and Vite. VITE_VERCEL_URL is probably the variable you are looking for.

[Balastrong]

Done!

I also changed the name attribute to property for og tags as that's what meta recommends and in fact I also noticed something was missing in title/description when sharing the url so that may be one more needed fix.

Let's see what happens in the vercel preview :D