test(#2591): update queue tests for Done-nodes-vanish semantics

Two tests asserted the old behaviour where completed nodes/DAGs stayed
in the snapshot. Under the redesign, Done nodes are filtered off the wire
(a fully-Done DAG disappears; a Failed one lingers + is history-capped):
- failed_node test: the completed reconcile is Done → assert it's absent,
  not Done-present (its run is already verified by the claim).
- history-eviction test: fail the nodes so the DAGs linger (Done ones
  would vanish), then assert the grace window + per-template cap.

hive-c0re/src/job_queue/tests.rs

@@ -679,7 +679,12 @@ fn failed_node_cancels_downstream_but_afterany_reconcile_runs() {
     assert_eq!(by_kind("stop_for_update"), State::Cancelled);
     assert_eq!(by_kind("swap"), State::Cancelled);
     assert_eq!(by_kind("post_swap"), State::Cancelled);
-    assert_eq!(by_kind("reconcile"), State::Done);
+    // The AfterAny reconcile ran (claimed + completed Ok above) → it's `Done`,
+    // and `Done` nodes are excluded from the wire, so it's absent here.
+    assert!(
+        dag.nodes.iter().all(|n| n.kind != "reconcile"),
+        "the completed (Done) reconcile is filtered off the wire"
+    );
     assert_eq!(
         dag.nodes
             .iter()
@@ -917,9 +922,12 @@ fn history_evicts_old_terminals_per_template() {
             ),
         );
         let c = claim_one(&q);
-        // Completing the single work node rolls the container up terminal (its
-        // inline hook fires off the returned summary — no terminal-hook node).
-        q.complete_node(id, c.node_id, Ok(()));
+        // Fail the single work node so the DAG *lingers*: a fully-`Done` DAG
+        // drops off the wire entirely, but a `Failed` one is retained (+
+        // history-capped) so the operator can still triage it. Completing the
+        // node rolls the container up terminal (its inline hook fires off the
+        // returned summary — no terminal-hook node).
+        q.complete_node(id, c.node_id, Err("boom".to_owned()));
     }
     // Fresh terminals are inside the grace window: nothing evicts yet,
     // so a ~1s QueueDag poller can still observe every terminal state