refactor(#2897): carry the meta-update inputs on the MetaLock node

Second of the `Dag` field removals, and the same shape as the first:
`DagSpec`/`NodeKind::Dag` carried an `inputs: Vec<String>` that exactly
one node ever read. Both reads live inside `run_meta_lock` — the
`meta::lock_update` call and the `meta_update_cascade_agents` fan-out —
so the list now rides `NodeKind::MetaLock` itself.

The executor stops touching `Claim` for this node entirely: its dispatch
arm already destructured `MetaLock { sweep, fanout }`, so `inputs` joins
them and the `claim` parameter, which had no other use, is gone.

Falls out of that:
- `Claim::inputs` and `DagMeta::inputs` delete.
- `dag_view`'s DAG-level projection onto the `MetaLock` node reads the
  payload instead. The wire `NodeView::inputs` is unchanged: still
  populated on the `meta_lock` node alone.
- the boot sweep names no inputs (it bumps `hyperhive` alone via
  `lock_update_hyperhive`), which the construction site now says out loud
  rather than leaving implicit in an empty DAG-level field.

Checked with clippy (`--all-targets -D warnings`), `cargo test -p
hive-c0re` (320 passed) and `nix fmt`. No option surface is touched, so
no nix-eval gate.

hive-c0re/src/job_queue/templates.rs

@@ -367,7 +367,6 @@ pub fn rebuild(agent: &str, source: Source, reason: String, relock: bool) -> Dag
     DagSpec {
         source,
         reason,
-        inputs: Vec::new(),
         transient: Some(TransientKind::Rebuilding),
         nodes,
     }
@@ -403,7 +402,6 @@ pub fn approval_deploy(agent: &str, approval_id: i64, reason: String) -> DagSpec
     DagSpec {
         source: Source::Approval,
         reason,
-        inputs: Vec::new(),
         transient: Some(TransientKind::Rebuilding),
         nodes: vec![
             node(
@@ -462,7 +460,6 @@ pub fn reconcile_only(
     DagSpec {
         source,
         reason,
-        inputs: Vec::new(),
         transient,
         nodes: vec![node(
             NodeKind::Reconcile {
@@ -488,7 +485,6 @@ pub fn spawn(agent: &str, approval_id: i64, reason: String) -> DagSpec {
     DagSpec {
         source: Source::Approval,
         reason,
-        inputs: Vec::new(),
         transient: Some(TransientKind::Spawning),
         nodes: {
             let a = || agent.to_owned();
@@ -533,7 +529,6 @@ pub fn perm_change(agent: &str, source: Source, reason: String, payload: PermPay
     DagSpec {
         source,
         reason,
-        inputs: Vec::new(),
         transient: Some(TransientKind::Rebuilding),
         nodes,
     }
@@ -559,6 +554,7 @@ pub fn meta_update(
         NodeKind::MetaLock {
             sweep: false,
             fanout: None,
+            inputs,
         },
         Vec::new(),
     )];
@@ -572,7 +568,6 @@ pub fn meta_update(
     DagSpec {
         source,
         reason,
-        inputs,
         transient: Some(TransientKind::Rebuilding),
         nodes,
     }
@@ -595,7 +590,6 @@ pub fn reparent(
     DagSpec {
         source,
         reason,
-        inputs: Vec::new(),
         transient: None,
         nodes: vec![node(NodeKind::Reparent { moves }, Vec::new())],
     }