Row 191's #processingGate refuses agent verbs off its read list while
processing is halted. grants.status joins hosts.status on that list, per
the kill-switch plan (2026-10-20_kill-switch.md:16): reads still work.
An agent's grants.revoke stays refused while halted, as hosts.revoke is.
Gitea grant executor (steps 0-8, settle, restart, revoke and fire, sweep,
status), the grants.* verbs and mosaic grants, the 3j-3k migration with
gitea_users and gitea_grants, and the section 9 tests with a fake Gitea and
a scratch gitea/gitea:1.27.1 X-G3 test. Build notes in
agents/megavolt/work/queue-236/BUILD.md.