There are three ways a security guardrail can fail you. Two of them are loud. One of them is a serial killer. It's down. Crashed, misconfigured, not deployed. You find out fast — errors, alerts, a red dashboard, an on-call page at 3am. Painful, but honest. It's weak. It runs, it catches some attacks, it misses others. You can measure it, argue about it, improve it. Also honest. It's running perfectly, passing every health check, returning valid scores on every request — and c...