GET /api/conf no longer returns smtp.pass / oauth.jwtSecret in cleartext
(masked to ********). POST treats a blank or ******** secret submission as
"keep the stored value," so editing the From address or token lifetimes no
longer requires re-entering or leaks the SMTP password / JWT secret. The /conf
form fields carry a leave-unchanged hint. Storage stays in OpenBao at
secret/sso-manager/conf (unchanged); no theta-suite policy change needed.
Co-Authored-By: Claude <noreply@anthropic.com>