fix: finalize failed batch enqueue atomically

src/worker/mod.rs

@@ -703,12 +703,12 @@ struct TaskContext {
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
-enum TaskProcessOutcome {
+pub(crate) enum TaskProcessOutcome {
     Done,
     LeaseBusy,
 }
 
-async fn process_task(
+pub(crate) async fn process_task(
     state: &AppState,
     task_id: Uuid,
     worker_id: Uuid,