Actor profile URL in ActivityStreams data

Hi there! While implementing ActivityPub mentions in WriteFreely, I noticed that Funkwhale doesn't return an actor's standard profile URL in the ActivityStreams data. This means that other platforms can't easily send browser-based visitors to a standard Funkwhale profile, as seen when clicking @bear@open.audio in this test post.

Besides our own use case, I imagine it'll be useful to have this improved a bit as federation develops in Funkwhale.

Potential solutions

One possible solution would be to simply add the url property in the actor data -- in my example, it'd be "url": "https://open.audio/@bear". This is one thing we personally do in WF, and something I've seen on other platforms.

Another might be to redirect visitors to the web-based URL if a client isn't requesting the /federation/actors/{username} endpoint with an Accept header related to ActivityPub. This is also something we personally do in WF, and again seems common in AP platforms. But those are just two ideas.

What are the possible drawbacks or issues with the requested changes?

The first potential solution seems to be lowest-impact, but the second would mean that clients must send the correct headers to get valid ActivityStreams data from Funkwhale.

Please let me know if I can help with any missing information, testing fixes, etc.