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.

configuration.nix

@@ -144,6 +144,7 @@
 
   sops.templates."openclaw.env" = {
     content = ''
+      OPENCLAW_GATEWAY_TOKEN=local_bypass_token_for_openclaw_12345
       DISCORD_TOKEN=${config.sops.placeholder.openclaw_discord_token}
       ZAI_API_KEY=${config.sops.placeholder.openclaw_zai_api_key}
       BRAVE_API_KEY=${config.sops.placeholder.openclaw_brave_api_key}

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,