fix(openclaw-bridge): include nonce in device handshake params

The gateway expects device.nonce (the challenge nonce) to be echoed
back in the connect request. Without it the connection is rejected with
'device: must have required property nonce'.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/openclaw-bridge/src/openclaw-client.ts

@@ -164,6 +164,7 @@ export class OpenClawClient {
         auth: { token: this.token },
         device: {
           id: this.deviceId,
+          nonce: nonce,
           publicKey: pubKeyDer.toString('base64'),
           signature: signature.toString('base64'),
           signedAt: Date.now(),