jobq: a transient is any running node naming the agent

Per mara on #2822: status is the only test. The agent comes off the
node's own payload rather than a declared Resource::Agent edge, so the
lease-exempt kinds (Prebuild, MetaSync) that name an agent without
holding its lease now light a pill — they are work on that agent.

Dropping that test breaks the one-pill-per-agent invariant, since
lease-exemption is exactly what lets one DAG build for an agent while
another holds its lease. Everything keyed by agent alone had to follow:

- reconcile_transients keys (agent, label) via TransientSeen, so a
  second pill cannot evict the first — and cannot lose its
  takes_container_down, which the crash watcher reads at clear time.
- transient_snapshot returns a Vec per agent for the same reason. The
  collapse was silent: a Prebuild could evict a StopForUpdate and its
  deliberate_stop, making an intentional stop report as a crash.
- crash_watch asks whether ANY running node expects the container down.
- the dashboard renders one row per node instead of one per agent.

takes_container_down never reached the frontend; no wire change needed.

315 tests pass unchanged.

hive-c0re/src/workers/crash_watch.rs

@@ -91,9 +91,13 @@ fn emit_crash_transitions(coord: &Coordinator, prev: &HashSet<String>, current:
         // Two sources, because a container can go down on purpose either way:
         // a running queue node that declared it takes the container down, or a
         // no-node operation (destroy, migration) holding a suppression guard.
+        // `any`, not "the" pill: an agent can have several running nodes at
+        // once (a lease-exempt build alongside a lease-holding stop), and it
+        // only takes one of them expecting the container down for this to be
+        // a deliberate stop rather than a crash.
         let active = transients
             .get(stopped)
-            .map(|st| st.deliberate_stop)
+            .map(|sts| sts.iter().any(|st| st.deliberate_stop))
             .or_else(|| coord.crash_watch_suppressed(stopped).then_some(true));
         let recently_cleared = recent.get(stopped).copied();
         if is_deliberate_stop(active, recently_cleared) {