PATCH /collections/{slug} with tracks_work or awaits_human merges into the
stored settings. When those are not a JSON object (import, a hand edit, an
old row), the merge failed with a plain error and answered 500. It now
wraps models.ErrSettingsNotObject, and both collection handlers map it to
400 validation_error with the same text. A full settings write still
repairs the row.
Over HTTP only the flags-only update can reach it: the request decoder
already refuses incoming settings that are not an object (IDEA-1488), so
the create mapping is defensive and commented as such. The tests pin the
decoder's 400 for those doors so they cannot regress to a 500.
Claude-Session: https://claude.ai/code/session_01EZ6hZzQiytCeBxXrtCWcVd
xarmian
a16d76f9d5