Squash of Morgana's 7f07da4aa..f869fd062 on origin/morgana/row193a (diff
from R1's candidate 44e36fc4c), the three manifest paths, manifest d38de8c9
(Duckworth approve, comment 29595). LEVELS gains collaborator and viewer,
covers() takes a required least level, and an unknown grant level covers
nothing. Gate on base 4385b9ec1 with the patch: packages and
scripts/test-*.sh 2789 pass 0 fail. Refactor moved to c9f374284 since, a
SESSIONS line only. Mutants 7 of 7 killed (agents/morgana/work/queue-193a/
mutants.log on the branch). No live change.