null対策

data/src/main/java/one/nem/kidshift/data/impl/TaskDataImpl.java

@@ -24,6 +24,9 @@ public class TaskDataImpl implements TaskData {
     public CompletableFuture<List<TaskItemModel>> getTasks() {
         return CompletableFuture.supplyAsync(() -> {
             TaskListResponse data = ksActions.syncTasks().join();
+            if (data == null) {
+                return null;
+            }
             return data.getList().stream().map(task -> {
                 // Convert TaskItemModel
                 TaskItemModel model = new TaskItemModel();