#98374 and #94847: a finished rebase and the first-edit open

After a rebase that stopped on a conflict in its last commit and was then continued, git keeps REBASE_HEAD while git status reports no rebase (#98374 cites git 2.43 and 2.50; below, 2.53.0).

finished-rebase.test.ts gives the diff mod a git directory holding only that file, edits /work/app.ts three times, and checks what the pane does:

| Tree | Pane after the edits | Test |