feat(refresh): keep Genshin event articles beside the snapshots

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

test/refresh.test.ts

@@ -973,6 +973,7 @@ describe("what the runner reports to the runner", () => {
       },
     ],
     changed: 0,
+    articlesChanged: 0,
     attempted: 1,
     confirmed: 0,
     warnings: ["genshin-game8-events: HTTP 403 (cloudflare, cf-ray)"],