Update internal/strutil/random_hex.go

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: lpcox

internal/strutil/random_hex.go

@@ -9,6 +9,9 @@ import (
 // RandomHex returns a hex-encoded string of n cryptographically random bytes.
 // The returned string has length 2*n.
 func RandomHex(n int) (string, error) {
+	if n < 0 {
+		return "", fmt.Errorf("failed to generate random bytes: negative size %d", n)
+	}
 	b := make([]byte, n)
 	if _, err := rand.Read(b); err != nil {
 		return "", fmt.Errorf("failed to generate %d random bytes: %w", n, err)