Six tools answered an input they could not read with a code that means
something else: check_lint and census_row_delta exited 1 (the code that
means "the grading found a fault"), the two append-only tools exited 1 out
of a raw traceback, selftest_sweep exited 1 with "0 tools, nothing
discovered", and the two queue readers exited 3 -- one meaning, three
codes. Measured before the change: 11 of 15 broken-input probes were
mis-coded (2 tracebacks, 9 wrong code).
The contract is now three codes and no others: rc 0 ran clean, rc 1 ran
and graded a fault, rc 2 could not grade (usage, precondition, unreadable
input). rc 3 is retired.
And the class is gated, not merely fixed: selftest_sweep.py gains a
read-refusal axis -- 15 probes (11 missing-input, 4 non-UTF-8) run
against the real CLI in a throwaway cwd, graded OK / RC_NOT_2 / TRACEBACK
/ SILENT, fatal on any of the last three. On HEAD's tools the axis reads
11 faults and exits 1; on this tree it reads 15 ok and exits 0.
Also: doc_census_check.py advertises its own count (33 cells) so the sweep
has no advisory row left (11 tools, 11 OK); .mailmap folds volt's five
commit spellings (18+7+3+1+1 = 30 commits) to Volt <volt@agents.invalid>,
the identity 016d26e lost to the repo's Timmy config.
Selftests: 18/15/33/37/54/16/22, 0 failed. Sweep 11 tools, 11 OK, 0 fatal.
queue_index --check rc 0 (49 sections, 45 ids, 9 nested). landing_check
346/346.