Development record

.abcd/development/brief/04-surfaces/30-inbox.md:30-32 says a waiting file this abcd cannot read is listed as unreadable, never dropped, and that a file that is not a report says so. The list reads only names matching fileNameRe (internal/core/report/inbox.go:89, 373). A file named notes.md in the inbox is absent from `abcd inbox`, its tally and its unreadable rows; only a report-shaped name is listed as unreadable.