Hook called after every ConduitMcp.Ext.Tasks state change (experimental, unstable).

The default is ConduitMcp.Ext.Tasks.ListenNotifier, which delivers notifications/tasks over subscriptions/listen to the task owner's streams. Configure another with config :conduit_mcp, :ext_tasks, notifier: MyNotifier (it replaces the default; call ConduitMcp.Ext.Tasks.ListenNotifier.task_changed/1 from it to keep listen delivery), or notifier: nil for none.

task_changed/1 runs in the process that made the change (a request process or the task's worker) right after the store write; an exception is logged and swallowed, so a notifier cannot fail a request or a worker.

A notifier that delivers a change to clients must deliver it only to the record's owner (the same owner check as tasks/get). A notifier can also wake a worker waiting on tasks/update input. ConduitMcp.Ext.Tasks.to_wire/1 builds the notification's task state.