job_queue: add NodeKind::Reparent (topology moves as a queue node, #2719)

hive-c0re/src/job_queue/tests.rs

@@ -13,6 +13,10 @@ fn submit(q: &JobQueue, spec: DagSpec) -> u64 {
     q.submit(spec).expect("valid spec")
 }
 
+fn ident(s: &str) -> hive_types::Ident {
+    hive_types::Ident::parse(s).expect("valid test ident")
+}
+
 fn rebuild(agent: &str, reason: &str) -> DagSpec {
     templates::rebuild(agent, Source::Manual, reason.to_owned(), true)
 }
@@ -1357,3 +1361,52 @@ fn perm_change_shape_prefixes_rebuild_chain() {
     }
     assert_eq!(state_of(&q, id), State::Done);
 }
+
+#[test]
+fn reparent_shape_is_a_lone_agentless_meta_window_node() {
+    // Single-move `set-parent` shape: one node, no rebuild subgraph (no
+    // container rebuild needed for a parent move), agentless like
+    // `MetaLock`, and it must declare the meta window — a topology commit
+    // must not land inside another node's staged deploy window.
+    let q = JobQueue::new(1);
+    let id = submit(
+        &q,
+        templates::reparent(
+            vec![(ident("alice"), Some(ident("bob")))],
+            Source::Manual,
+            "set-parent".to_owned(),
+        ),
+    );
+    let c = claim_one(&q);
+    assert_eq!(c.kind.as_str(), "reparent");
+    assert_eq!(c.agent, "", "Reparent is agentless — no per-agent lease");
+    assert!(
+        c.kind.needs_meta_window(),
+        "a topology commit must hold the same MetaWindow as WritePermFile"
+    );
+    assert!(!c.kind.needs_lease());
+    assert!(!c.kind.needs_build_slot());
+    q.complete_node(id, c.node_id, Ok(()));
+    assert_eq!(state_of(&q, id), State::Done);
+}
+
+#[test]
+fn reparent_bulk_shape_carries_every_move_on_one_node() {
+    // `set-parent-bulk`: still ONE node (one git commit, `moves.len() > 1`),
+    // not one node per move — bulk atomicity across every move in the
+    // request is the reason a single node was chosen in the first place.
+    let moves = vec![(ident("alice"), Some(ident("bob"))), (ident("carol"), None)];
+    let q = JobQueue::new(1);
+    let id = submit(
+        &q,
+        templates::reparent(moves.clone(), Source::Manual, "set-parent-bulk".to_owned()),
+    );
+    let c = claim_one(&q);
+    assert_eq!(c.kind.as_str(), "reparent");
+    let NodeKind::Reparent { moves: got } = &c.kind else {
+        panic!("expected a Reparent node, got {:?}", c.kind);
+    };
+    assert_eq!(got, &moves);
+    q.complete_node(id, c.node_id, Ok(()));
+    assert_eq!(state_of(&q, id), State::Done);
+}