SignedData now requires one SignerInfo with a non-empty signature and a
complete issuerAndSerialNumber. Certificate names share a 64 KiB decoded-byte
budget and are copied once. A security directory that ends in a short
WIN_CERTIFICATE header fails instead of reporting a complete table. The
certificate CLI forwards the caller abort signal into cleanup.
Co-authored-by: morluto <morluto@users.noreply.github.com>