feat: allow production provider bootstrap

deploy/ack/configmap.yaml

@@ -14,6 +14,9 @@ data:
   ZHINIAN_AUTH_COOKIE_SECURE: "true"
   ZHINIAN_PUBLIC_BASE_URL: https://REPLACE_WITH_PUBLIC_HOST
   ZHINIAN_GO_EMBEDDED_WORKER: "true"
+  # Temporary bootstrap switch only. Keep false for steady-state production;
+  # when true, unconfigured provider requests return 503 until restart.
+  ZHINIAN_ALLOW_UNCONFIGURED_PROVIDERS: "false"
   ZHINIAN_RUNTIME_DIR: /var/lib/zhinian/runtime
   ZHINIAN_LOG_DIR: /var/lib/zhinian/logs
   ZHINIAN_SETTINGS_FILE: /var/lib/zhinian/settings.env