docs: stop asserting DagView/NodeView after their deletion

The deletion PR removed the types but left ~10 sites still describing
them. Two are real breakage rather than staleness: rustdoc intra-doc
links to deleted items ([NodeView::kind] and [Self::snapshot] in
job_queue/mod.rs). Neither clippy --all-targets -D warnings nor cargo
test resolves intra-doc links, so the tree was green with both already
dangling.

The rest reassert facts the deletion made false: docs/coordinator.md
documented the event as RebuildQueueChanged { seq, queue: [DagView...] }
with a per-node field list, and three sites pointed at the removed
/api/state.rebuild_queue endpoint.

One is pointer rot rather than a rename, and no grep for a deleted name
finds it: SchedulesChanged justified itself as "same snapshot-shape
rationale as RebuildQueueChanged" -- which the deletion turned into the
one event that is not a snapshot. Repointed at TombstonesChanged /
MetaInputsChanged, in both the Rust doc and the dashboard doc.

Two are pre-existing and strictly out of scope, swept under the
pfadfinderregel because the same grep surfaced them: hive-sh4re/README
advertised a jobs module that crate has not had since the host-sock
split, and hive-host-sock/README claimed its own payload types live in
hive-sh4re.

Docs and comments only -- no behaviour, no API, no test changes.

hive-c0re/src/job_queue/model.rs

@@ -322,7 +322,8 @@ impl hive_jobq_wire::WireNode for NodeKind {
 }
 
 impl NodeKind {
-    /// Wire string for `NodeView.kind`.
+    /// Wire string for the node's label on the graph wire
+    /// ([`hive_jobq_wire::WireNode::label`]).
     pub fn as_str(&self) -> &'static str {
         match self {
             NodeKind::MetaSync { .. } => "meta_sync",