How do I restore a hidden commit (i.e. "un-abandon" it)? Why don't branch set and edit do this automatically?

[BatmanAoD]

[While writing this, I answered the first part of my own question, so I'll add that as an answer. The question about branch set and edit remains.]

I screwed up a rebase, and after a couple jj op restore <id>s, I eventually managed to find a repository state in which a particular commit I had lost was visible, but still hidden, using jj log -r <commit-hash>. I tried to "restore" the commit by assigning a branch to it, but that didn't work:

❯ jj log -r <branchname>
○  twtyyppm hidden [email protected] 2024-09-25 13:47:06 <branchname>* 5b942ee9
│  <description>
~

Even making that my working copy doesn't un-hide it:

❯ jj edit <branch>
Working copy now at: twtyyppm hidden 5b942ee9 <branch>* | <description>
Parent commit      : puxvrypl hidden b3d4fca2 <description>
Added 0 files, modified 5 files, removed 0 files

[BatmanAoD]

To answer the first part, how to restore the commit, making a new commit on top of the hidden one restored it:

❯ jj new
Working copy now at: kymqltqp b6ec8e3f (empty) (no description set)
Parent commit      : twtyyppm 5b942ee9 <branch>* | <description>

[yuja]

69edc7f should fix the problem of jj edit. branch set/move have the same problem. They should probably re-add visible heads or reject hidden commits.