The revert hook is dead by construction, so it can only ever be wrong.
DAG state `Cancelled` has exactly one producer: `JobQueue::cancel`, which
refuses unless every work node is still `Pending`. A cancel *cascade*
(some node failed, downstream cancelled) rolls up `Failed` instead —
`dag_rollup` short-circuits on any failed subtree node. So on a DAG that
reaches `Cancelled`, no node ever executed: the `SetWanted` head provably
never ran and `wanted` still reads whatever the operator last set it to.
There is therefore nothing to revert, and `revert_intent` did not revert
anything — it wrote `Wanted::from_running(observed)`, i.e. the agent's
*observed* state, over an intent the DAG never touched. Harmless when
observed already matched, silent corruption otherwise: cancel a queued
start for an agent that is down but `wanted = Up` (crashed, or caught
mid-bounce) and the intent flips to `Offline`, leaving it
deliberately-stopped as far as reconcile and crash-watch are concerned.
The hook made sense when `set_wanted` was a pre-submit side effect
written before the DAG ran; moving it into the DAG as a node left the
hook vestigial.
Drop `HookKind::RevertIntent`, `revert_intent`, and the power-op arm of
`terminal_hook` — start / stop / graceful-stop now settle with no
terminal hook, same as restart always did. The test asserts the general
statement across restart/stop/start x graceful x running: stop and start
carry a `SetWanted` head, and cancelling them still fires no hook.
5c4a637941