fix: emit SchedulesChanged from manager-server + approval paths

Agent-triggered schedule mutations (cancel_schedule, fire_schedule_now,
edit_schedule MCP tools) go through manager_server.rs, not the HTTP API
handlers. Approval-resolved SchedulePrompt inserts go through actions.rs.
Neither was emitting SchedulesChanged.

- manager_server.rs: add emit_schedules_snapshot() on Ok in
  handle_cancel_schedule, handle_fire_schedule_now, handle_edit_schedule
- actions.rs: emit_schedules_snapshot() after successful
  run_approval_schedule_prompt (covers request_schedule_prompt approval
  resolving)

Coverage is now complete: every path that writes a scheduled_prompts row
emits the SSE snapshot.

hive-c0re/src/actions.rs

@@ -116,7 +116,11 @@ pub async fn approve(coord: Arc<Coordinator>, id: i64) -> Result<()> {
             // at the scheduled time). Run inline + fire
             // `ApprovalResolved` so the approval row leaves Pending
             // immediately.
-            run_approval_schedule_prompt(&coord, approval).await
+            let result = run_approval_schedule_prompt(&coord, approval).await;
+            if result.is_ok() {
+                coord.emit_schedules_snapshot();
+            }
+            result
         }
     }
 }

hive-c0re/src/manager_server.rs

@@ -610,7 +610,10 @@ fn handle_cancel_schedule(
             .map_err(|e| format!("cancel all: {e:#}")),
     };
     match result {
-        Ok(()) => ManagerResponse::Ok,
+        Ok(()) => {
+            coord.emit_schedules_snapshot();
+            ManagerResponse::Ok
+        }
         Err(message) => ManagerResponse::Err { message },
     }
 }
@@ -647,7 +650,10 @@ async fn handle_fire_schedule_now(
         };
     }
     match crate::scheduled_prompts_worker::fire_now(coord, schedule_id).await {
-        Ok(_report) => ManagerResponse::Ok,
+        Ok(_report) => {
+            coord.emit_schedules_snapshot();
+            ManagerResponse::Ok
+        }
         Err(e) => ManagerResponse::Err {
             message: format!("fire schedule {schedule_id} now: {e:#}"),
         },
@@ -709,7 +715,10 @@ fn handle_edit_schedule(
         targets_remove,
     };
     match coord.scheduled_prompts.update(schedule_id, patch) {
-        Ok(()) => ManagerResponse::Ok,
+        Ok(()) => {
+            coord.emit_schedules_snapshot();
+            ManagerResponse::Ok
+        }
         Err(e) => ManagerResponse::Err {
             message: format!("edit schedule {schedule_id}: {e:#}"),
         },