ManavA laptop swap mid-shift used to be a detection problem, "who took over the keyboard?" Manav reframes it as a step-up authentication problem. Every meaningful action demands a fresh, payload-bound passkey ceremony. An attacker holding the laptop still cannot satisfy Face ID. The swap becomes useless.
The attacker inherited everything: the browser session, the API tokens, the VPN tunnel, the active SSH keys. What they didn't inherit was the ability to generate a fresh passkey ceremony. Lin's Face ID lives in Lin's Secure Enclave on Lin's phone, not in the laptop, not in the session cookie. Every consequential action above demanded a new ceremony bound to the exact payload hash. The gate doesn't ask "is this the same session?", it asks "is a human here, right now, approving this exact thing?" The swap is visible not because the attacker was detected, but because they couldn't sign.