env/headers are sealed into secretCipher with the BYOK AES-GCM/HKDF box. The admin GET returns masked values; a mask posted back for the same server and key keeps the stored value, any other mask is a 400. The chat and the test button use the stored values. upgradeAiData seals plaintext v1 rows. Co-Authored-By: Claude Opus 5.5 <[email protected]>