New key ID 1D1E33AC50B11BC2 replaces ABB078FD8EBFF5FA, whose private half had
no recoverable backup. Rotation is free at this exact moment: the v1.0.0
fleet predates signature verification entirely and no verifying (alpha.1+)
install exists yet. Both SERVER_UPDATE_SIGNING_* secrets updated in lockstep;
private key + password backed up locally for the maintainer.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>