CVE-2026-55164: Lemur user-update path stores plaintext passwords

lemur.users.service.update() writes a user’s new password as plaintext to the users.password column. The User model wires bcrypt hashing to SQLAlchemy’s before_insert event but registers no equivalent listener for before_update, and service.update() does not call user.hash_password() after assigning the new value. Every password change performed through the admin-gated PUT /api/1/users/<id> endpoint persists the user’s password to the database in cleartext.