fix: make service control robust against partial service absence

.sisyphus/ralph-loop.local.md

@@ -0,0 +1,9 @@
+---
+active: true
+iteration: 1
+max_iterations: 100
+completion_promise: "DONE"
+started_at: "2026-02-08T04:16:19.890Z"
+session_id: "ses_3c4892488ffe22XCFLNy3XIbZ3"
+---
+把验证码功能换成cloudflare turnstile，删除原来的验证码，只使用cloudflare turnstile，可以让用户填写cloudflare turnstile的token以启用验证码，先给出计划