Recommend object URL should 301 to AP resource

Earlier this month, I discovered that Ghost's latest blog post didn't make it into NodeBB, due to a bug on my end. I attempted to resolve it via URL but there was no AP resource at that URL. I ended up having to query the instance actor (which I happened to already know), and looking at the outbox.

There is some guidance here as to how to handle these types of situations.

But basically, if you're able to have Ghost serve the activity+json response for the URL (based on Accept header), that would be ideal. It's a common use-case for users of the open social web. If you cannot serve the activitypub payload on that same url, then a 302 redirect to the AP payload would also work great 😄

Thanks!

Start by tracing how Ghost object URLs are handled for ActivityPub requests, using the linked ActivityPub HTML discovery guidance and the Accept header behavior described in the issue. Verify that an object URL returns the ActivityPub response when requested with the appropriate media type, or redirects to the AP payload when it cannot do so.