Implement database administration

Add routes and admin panel elements for creating a database backup,
restoring from a backup, deleting the existing schedule, and replacing
the database with the demo schedule.  These server as crude ways to
manage the data stored in the system.

server/api/admin/delete-schedule.post.ts

@@ -0,0 +1,11 @@
+import { writeSchedule } from "~/server/database";
+import type { ApiSchedule } from "~/shared/types/api";
+
+export default defineEventHandler(async (event) => {
+	await requireServerSessionWithAdmin(event);
+	const schedule: ApiSchedule = {
+		id: 111,
+		updatedAt: new Date().toISOString(),
+	};
+	await writeSchedule(schedule);
+})