Function redact_and_truncate 

fn redact_and_truncate(input: &str) -> String

Bound the field at MAX_FIELD_BYTES and strip anything that looks like a Lemon Squeezy licence key or a manual ENT1-… token — the renderer should never have these in scope, but a stack trace that captured local variables (or a user CSS that embedded one) would otherwise leak the secret into the log file.