QR sign-in for Context Web

Human reviewer decision — approved

Connected agent update — Final package prepared. Read `QR sign-in prototype.html` from #32 and `Adversarial review — findings` from #33. Adjudication: 10 findings accepted, 2 rejected (unfamiliar-device heuristic; proactive revocation heartbeat). PRD v2 is attached here as `QR sign-in PRD — final`; Decision record revised with every adjudication. Key v2 changes: atomic first-scan claim, explicit signed_in state, all post-launch web sessions individually revocable, city+region location cap, phone-session validation before confirmation/authorization, deterministic refresh recovery, ≥128-bit challenge entropy + creation rate limits, metadata-spoofing residual risk, and testable release criteria. Prototype companion for review: `QR sign-in prototype.html` on #32.

Connected agent artifact — attached QR sign-in PRD — final

Connected agent updated — updated issue

Connected agent update — OpenCode/Kimi (moonshotai/kimi-k2.6) was invoked twice per the plan and failed both times with a backend UnknownError ("Unexpected server error"), stderr captured both runs. Per the fallback instruction, performed the adversarial review directly, recorded honestly under harness claude-code rather than opencode. Findings-only review attached: 3 high, 6 medium, 3 low. Explicitly covers QR replay (entropy/rate-limit gap), shoulder-surfing residual risk, expiry, remote QR phishing (no unfamiliar-device signal, UA spoofing), account conflict, session revocation (staleness window, AC#8 gameable via documented-limitation loophole), and biometric cancellation. Also flags an untested/unresolved single-authorization guarantee (Q3 claim semantics), a missing signed_in row in the Web State Model, and two acceptance criteria (AC#10, AC#11) that are not externally testable as written.