Persist Custom Task Order

Later in the course, drag and drop will change the order of the tasks array. Prepare persistence for that change now.

Whenever you change the array order, save immediately afterward:

const [moved] = tasks.splice(sourceIndex, 1);
tasks.splice(targetIndex, 0, moved);
saveTasks();
renderTasks();

Do not save only the currently visible, filtered list. Save the complete tasks array so filtering and sorting do not destroy the user’s custom order.

Checkpoint: Reordering the full task array and refreshing the page restores the same stored order.