Re: [CfC] Erratum for ActivityPub on the definition of `inbox` the property

Thank you for clarifying, Ben. I have commented on the GitHub issue with
further details, but it seems that the disconnect was that both the inbox
and outbox descriptions were flawed for different reasons. I had overlooked
the outbox confusion, whereas the errata addressed the inbox confusion.
More details can be found in
https://github.com/w3c/activitypub/issues/289#issuecomment-2954206997 for
those interested in the discussion.

To confirm, my position is indeed that `outbox` (and `inbox`) can be either
references or embedded nodes. This is a JSON-LD thing that should be
pointed out more generally than in the descriptions of these properties, as
Arnold Schrijver's comment points out similar unaddressed issues with
`following`, `followers`, and `liked` being described as "A link to..."
despite also being valid when embedded.

I think I understand now the concern that adopting the original errata and
closing the issue would have essentially left it only partially resolved,
and I have filed the following issues as adjacent:

- Clarify that JSON-LD allows ActivityPub properties to be either
references or embedded #506 <https://github.com/w3c/activitypub/issues/506>
- Use of "A link to..." with followers, following, liked #505
<https://github.com/w3c/activitypub/issues/505>

Tangentially, a new issue was discovered while processing this issue:

-  Example 9 uses an array for icon despite having only a single value #507
<https://github.com/w3c/activitypub/issues/507>

Thank you for your attention and diligence in this matter!