feat: live SSE updates for the SCH3DUL3S tab

Add `SchedulesChanged` to the dashboard event channel so the
operator's schedule list updates in real time without requiring a
tab-activation or form-submit refresh.

Backend:
- `dashboard_events.rs`: new `SchedulesChanged { seq, schedules }`
  variant carrying a full `Vec<WireSchedule>` snapshot (same
  snapshot-over-diff rationale as `RebuildQueueChanged`).
- `coordinator.rs`: `emit_schedules_snapshot()` helper — queries the
  scheduled_prompts list, converts to wire shape, broadcasts the event.
- `dashboard.rs`: call `emit_schedules_snapshot()` at the end of each
  operator API handler that mutates a schedule:
  `post_schedule_new`, `post_schedule_fire_now`,
  `patch_schedule`, `post_schedule_cancel`.
- `scheduled_prompts_worker.rs`: call `emit_schedules_snapshot()`
  after each tick that fires schedules, so `last_fired_at_unix`,
  `next_fire_at_unix`, and reaped one-shots surface live.

Frontend:
- `tabs.js`: add `applySchedulesChanged(ev)` — replaces
  `schedulesState` from the snapshot and calls `renderSchedulesList()`.
  Registered in `MUTATION_HANDLERS` as `schedules_changed`.
  Tab-activation re-fetch kept as safety net for approval-path
  inserts and disconnect windows; comment updated to reflect this.

Docs:
- `docs/web-ui/dashboard.md`: document `schedules_changed` event.
- `CLAUDE.md`: add `SchedulesChanged` to the file-map entry.

hive-c0re/src/coordinator.rs

@@ -368,6 +368,27 @@ impl Coordinator {
         });
     }
 
+    /// Emit a `SchedulesChanged` snapshot event. Called from every
+    /// schedule mutation site (operator API handlers + the worker
+    /// after each tick that fires or rearms a row) so the dashboard's
+    /// scheduled-prompts tab updates live without polling.
+    pub fn emit_schedules_snapshot(self: &Arc<Self>) {
+        let schedules = match self.scheduled_prompts.list() {
+            Ok(rows) => rows
+                .into_iter()
+                .map(crate::manager_server::schedule_to_wire_public)
+                .collect(),
+            Err(e) => {
+                tracing::warn!(error = ?e, "emit_schedules_snapshot: list failed");
+                return;
+            }
+        };
+        self.emit_dashboard_event(DashboardEvent::SchedulesChanged {
+            seq: self.next_seq(),
+            schedules,
+        });
+    }
+
     /// Update the `step` label on a running queue entry and (if it
     /// actually changed) re-emit the queue snapshot so the dashboard
     /// renders the new phase. Returns `true` when the label was new

hive-c0re/src/dashboard.rs

@@ -1964,7 +1964,10 @@ async fn post_schedule_new(
         source: crate::scheduled_prompts::ScheduleSource::Operator,
     };
     match state.coord.scheduled_prompts.submit(&new) {
-        Ok(id) => axum::Json(serde_json::json!({"id": id})).into_response(),
+        Ok(id) => {
+            state.coord.emit_schedules_snapshot();
+            axum::Json(serde_json::json!({"id": id})).into_response()
+        }
         Err(e) => error_response(&format!("schedule submit: {e:#}")),
     }
 }
@@ -1982,7 +1985,10 @@ async fn post_schedule_fire_now(
     AxumPath(id): AxumPath<i64>,
 ) -> Response {
     match crate::scheduled_prompts_worker::fire_now(&state.coord, id).await {
-        Ok(report) => axum::Json(report).into_response(),
+        Ok(report) => {
+            state.coord.emit_schedules_snapshot();
+            axum::Json(report).into_response()
+        }
         Err(e) => error_response(&format!("fire schedule {id} now: {e:#}")),
     }
 }
@@ -2093,7 +2099,9 @@ async fn patch_schedule(
     }
     match state.coord.scheduled_prompts.get(id) {
         Ok(Some(s)) => {
-            axum::Json(crate::manager_server::schedule_to_wire_public(s)).into_response()
+            let wire = crate::manager_server::schedule_to_wire_public(s);
+            state.coord.emit_schedules_snapshot();
+            axum::Json(wire).into_response()
         }
         Ok(None) => error_response(&format!("edit schedule {id}: row vanished post-update")),
         Err(e) => error_response(&format!("re-read schedule {id}: {e:#}")),
@@ -2117,7 +2125,10 @@ async fn post_schedule_cancel(
         None => state.coord.scheduled_prompts.cancel_all(id),
     };
     match result {
-        Ok(()) => (StatusCode::OK, "ok").into_response(),
+        Ok(()) => {
+            state.coord.emit_schedules_snapshot();
+            (StatusCode::OK, "ok").into_response()
+        }
         Err(e) => error_response(&format!("cancel schedule {id}: {e:#}")),
     }
 }

hive-c0re/src/dashboard_events.rs

@@ -192,6 +192,16 @@ pub enum DashboardEvent {
     /// dashboard's grouping (`parent_id`) is most naturally re-derived
     /// from the full list.
     RebuildQueueChanged { seq: u64, queue: Vec<QueueEntry> },
+    /// Full snapshot of all scheduled prompts. Emitted after every
+    /// operator mutation (new / edit / cancel / fire-now) and after the
+    /// worker fires or rearms a row. Same snapshot-shape rationale as
+    /// `RebuildQueueChanged` — the list is small and the client's
+    /// per-target `last_result` / `last_fired_at_unix` fields are most
+    /// naturally re-derived from the full list.
+    SchedulesChanged {
+        seq: u64,
+        schedules: Vec<hive_sh4re::WireSchedule>,
+    },
 }
 
 impl DashboardEvent {
@@ -222,6 +232,7 @@ impl DashboardEvent {
             DashboardEvent::MetaInputsChanged { .. } => "meta_inputs_changed",
             DashboardEvent::MetaUpdateRunning { .. } => "meta_update_running",
             DashboardEvent::RebuildQueueChanged { .. } => "rebuild_queue_changed",
+            DashboardEvent::SchedulesChanged { .. } => "schedules_changed",
         }
     }
 }
@@ -340,6 +351,10 @@ mod tests {
                 seq: 1,
                 queue: Vec::new(),
             },
+            DashboardEvent::SchedulesChanged {
+                seq: 1,
+                schedules: Vec::new(),
+            },
         ];
         for ev in samples {
             let v: serde_json::Value = serde_json::to_value(&ev).expect("serialise");

hive-c0re/src/scheduled_prompts_worker.rs

@@ -69,6 +69,9 @@ fn tick(coord: &Arc<Coordinator>) {
     if let Err(e) = coord.scheduled_prompts.reap_cancelled(cutoff) {
         tracing::warn!(error = ?e, "scheduled_prompts: reap cancelled failed");
     }
+    // Emit after all fires + reaps so the dashboard reflects updated
+    // last_fired_at_unix, next_fire_at_unix, and any reaped one-shots.
+    coord.emit_schedules_snapshot();
 }
 
 /// Fan out one schedule's body to every active target. Records