[feature] Add "published" property to AP Actor representation so other instances can show correct "Joined" date

[firescry]

Describe the bug with a clear and concise description of what the bug is.

I created user profile on GoToSocial instance in August 2023, but I wasn't using that account till May 2024. When I started using it, I've noticed that "Joined" date for my profile on remote Mastodon instances is incorrect - in most cases it shows the date of May 2024 or even later, instead of August 2023. I guess that they present the date of finding out of my profile.

What's your GoToSocial Version?

0.17.3+git-6f4cb2f

GoToSocial Arch

arm64

What happened?

Mastodon shows incorrect "Joined" date of my profile hosted on GoToSocial. I've noticed that other profiles are also affected by that problem, including official GTS account.

What you expected to happen?

Mastodon instances should show correct "Joined" date. That date shown directly in GTS and on Mastodon instances should be the same.

How to reproduce it?

1. Check "Joined" date for profile hosted on GTS, e.g. @gotosocial - It is "Jun, 2022"
2. Visit any Mastodon instance and go to the "Explore" section - e.g. https://mastodon.social/explore
3. Search for GTS-hosted profile (e.g. @gotosocial@superseriousbusiness.org) and open profile form the list of results (that step does not require having an account on that Mastodon instance as searching for profiles is publicly available)
4. Check the "Joined" date presented by Mastodon for the profile

I've followed these steps for @gotosocial profile on few instances and here are the results:

• mastodon.social - Joined: Jun 03, 2022 (looks correct)
• masto.ai - Joined: 07 Nov 2022 (off by few months)
• universeodon.com - Joined: Jan 23, 2023 (off by few months)
• social.freedom.press - Joined: 15 Nov 2024 (off by two years; this instance was created recently)

Anything else we need to know?

Please let me know if I should create a bug report for Mastodon instead.

Thank you for working on GTS! I really enjoy using it :heart:

[SadmL]

I guess this is not GtS-specific. And not Mastodon-specific too. Some days ago got a Sharkey account on recently created server, some profiles has "Joined" date same as server spin-up date on lookup.

[tsmethurst]

GtS doesn't currently serve the "published" property on AP Actor representations, so to resolve this then probably all we need to do is add this field. I'll change this to a feature request as it's not really a bug per se that we don't include this yet.