Add completion and answered marking

functions/api/events-team/events/[id]/solve.ts

@@ -0,0 +1,11 @@
+export async function onRequestPost(context: RequestContext) {
+  await context.env.D1.prepare(
+    "UPDATE events SET answered_at = ? WHERE id = ?;",
+  )
+    .bind(Date.now(), context.params.id)
+    .run();
+
+  return new Response(null, {
+    status: 204,
+  });
+}