Maity: Board

Review PR #147 (runner R6b: logs, approve, stop-all, gc, workspace claim)

tsk-04071n27fapw cancelled chore

Independent review of https://github.com/oliver-zehentleitner/maity/pull/147 (agent C), stacked on #145. Focus: gc --revoked deleting workspaces (path safety, only with --yes, never outside the state dir, symlinks), stop-all vs the running service, approve/awaiting_operator semantics vs §15, logs not leaking secrets. Deliver review_result to oz-agent-a. After #146 and #145.