Record one tenant-bound commerce action evaluation in Shadow Mode

The Commerce Gate MCP always submits SHADOW and requires the response to confirm SHADOW. commercegate_evaluate_action accepts all eleven canonical commerce action types: the seven published families and the four finance families (payment release, vendor bank change, early-payment discount and credit-hold release) of the unreleased commerce-preflight-v2 source candidate, which require a matching backend and never move money. For the live Walmart Marketplace connector, Commerce Evaluation, Price Guard, Order Guard, order interception, margin protection, release, hold, and cancel map to those canonical preflights. Order acceptance and price change use native margin mappings; inventory, fulfillment, promotion, refund, and return are generic Protocol evaluations whose outcome depends on the tenant policy and supplied signals. The unreleased commerce-preflight-v2 opt-in adds sixteen explicit policy checks with a matching backend and a server-owned policy bundle. It binds the result to the action, facts, policy version and idempotency key; missing required facts or unsupported checks hold the proposal. The candidate Commerce /aws facade preserves the original action/result key through its separately authenticated commerce-preflight-transport-v1 retry namespace. Its context.commerce_preflight_transport marker is reserved service metadata, not a tool argument. This does not establish hosted availability. It does not add native execution paths. commercegate_evaluate_marketplace_offer_submission accepts a separate, bounded Microsoft Partner Center or AWS Marketplace SaaS offer packet with digest-bound release evidence. Either evaluation can create decision evidence but never executes a marketplace action or submits an offer.