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/coordinator.rs

@@ -635,10 +635,14 @@ impl Coordinator {
         }
     }
 
-    /// Emit a `RebuildQueueChanged` snapshot event. Called from the
-    /// queue mutation helpers (`enqueue` / `finish` / `cancel`-adjacent
-    /// wrappers below) and the worker so every state transition
-    /// surfaces on the dashboard without extra plumbing.
+    /// Emit a `RebuildQueueChanged` tick. Called from the queue mutation
+    /// helpers (`enqueue` / `finish` / `cancel`-adjacent wrappers below) and
+    /// the worker so every state transition surfaces on the dashboard without
+    /// extra plumbing.
+    ///
+    /// Carries no queue payload — clients refetch `/api/jobq/graph`. The name
+    /// keeps `snapshot` because *that* is still what a client ends up with;
+    /// what changed is who serves it.
     pub fn emit_rebuild_queue_snapshot(self: &Arc<Self>) {
         self.emit_dashboard_event(DashboardEvent::RebuildQueueChanged {
             seq: self.next_seq(),