What a reader sees when the artifact endpoints refuse a read.
A wrong passcode, a missing passcode, and an id that matches nothing all come back as the
same 403 with the same message, on purpose — so the endpoint cannot be used to find out
which conversations exist or hold artifacts. That makes "you need this artifact's
passcode" the only reading a visitor can act on, and this page never claims an artifact
does or does not exist.
What a reader sees when the artifact endpoints refuse a read.
A wrong passcode, a missing passcode, and an id that matches nothing all come back as the same 403 with the same message, on purpose — so the endpoint cannot be used to find out which conversations exist or hold artifacts. That makes "you need this artifact's passcode" the only reading a visitor can act on, and this page never claims an artifact does or does not exist.