fix(openclaw): bypass device pairing requirement

- Change gateway auth mode from "none" to "token", as "none" is no longer supported and enforces device pairing.
- Provide a static OPENCLAW_GATEWAY_TOKEN in the environment to allow local subagents to bypass pairing automatically.

modules/openclaw-config.json

@@ -4,7 +4,7 @@
     "bind": "loopback",
     "trustedProxies": ["::1", "127.0.0.1", "10.88.0.0/16", "10.89.0.0/16"],
     "auth": {
-      "mode": "none"
+      "mode": "token"
     },
     "controlUi": {
       "dangerouslyAllowHostHeaderOriginFallback": true,