0018 — Offline simulator upstream

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Status: accepted Date: 2026-10-15 Owner: Core

Context

No Token Factory key exists on day one, CI must not call paid APIs, and the e2e suite needs deterministic model behavior.

Decision

RATCHET_UPSTREAM=sim routes the proxy to ratchet.sim, a deterministic stand-in that answers agent calls with scripted skill policies and judge calls with heuristics over the prompt sections.

Consequences

Everything it produces is labeled: Verdict.simulated_models=True and a 'Simulated models' badge in the UI. No README or video number may come from the simulator.

Reversal trigger

never shipped as the judged demo; live mode is the demo