Captures the exact request kwargs each provider hands to its SDK seam (Anthropic
messages.stream, OpenAI chat/responses create, Google OpenAI-compat) for a
representative set of trajectories, asserted against committed goldens. This is the
behavior-equivalence net the canonical-trajectory wire-shape refactor is proven
against. Regenerate the baseline with UPDATE_WIRE_GOLDENS=1.
Patrick Buckley