pub fn serialize_secret(plaintext: &str) -> SshCliResult<String>Expand description
Serializes a secret for TOML: encrypts if a key exists (or is auto-created); otherwise plaintext.
Empty secret never becomes a blob sshcli-enc (GAP-SSH-EXP-001): export redacted zera
passwords and must store readable "", not ciphertext of empty string (which fools import
on another machine without the primary-key and fakes “secret present”).
§Errors
Returns an error if key resolution, RNG, or AEAD encryption fails.