pub fn keyring() -> Vec<(u8, String)>Expand description
The full keyring for snapshot verification. Pulls APP_KEYS when set
("1:keyA,2:keyB" form — first entry is the active signing key); falls
back to a single (0, APP_KEY) pair when APP_KEYS is absent, so apps
that don’t rotate stay one-line.
Returned (kid, key) pairs are owned Strings — caller borrows as
&[(u8, &str)] before handing to Envelope::verify_with_keys.