420542ce10
The relay control password (relay_pw) was read by the driver but had NO form field, so Test connection sent it as 0 → the device ignored the probe → a controller showed "offline" even though it pinged. Add a "Relay control password" config field (secret; blank keeps the stored value). Because relayPassword is redacted from the client, the edit form can't resend it — so the test endpoint now re-merges the stored secret by device id (mirroring save). It is re-merged ONLY when the submitted config addresses the SAME device: matching driverId and every connection-identity field it sets (host/port/binaryPort/httpPort/serial). A redirected host/port or mismatched driver yields NO secret, so a probe can't exfiltrate the password to an attacker host (the booth operator is the threat-model adversary). testDevice() now passes the device id; setup-secrets.test.ts covers the identity guard. Claude-Session: https://claude.ai/code/session_01Xcm6ikLgGoCxxHrxtjkk5V