Add asc(tasks.completed) as the primary sort key in getOrderClauses()
so completed tasks always appear after active ones regardless of the
chosen sort mode (position, priority, dueDate, title, createdAt).
Also apply the same completed-first ordering to:
- getSubtasks() in tasks.ts
- noDateTasks query in widgetSync.ts
- subtasks query in widgetSync.ts
Ref: simpl-liste#15
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>