The common bad frame in a box is the last one, torn by a crash or kill in
the middle of a write. Recovery trims only that write, which never completed
and was never reported saved. With recovery off, that ordinary crash left
cloud sync off for good with no way back, worse than the rare mid-file
corruption it guarded against. The startup test now checks that a torn final
frame is trimmed and the ops before it survive.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>