Generate a no-spend native harness deployment preview

Authenticated preview for self-hosted or platform-hosted native harness agents. Target selection is precedence-based. An explicit hosting_target or target wins; otherwise an explicit endpoint selects self_hosted_http, and when neither is supplied the target defaults to platform_native_harness. A platform-hosted target clears any supplied endpoint instead of selecting self-hosting. Rejects inline secrets and validates listing economics from the raw request before normalization. Caller provider_state is reduced to a reviewed projection before persistence; raw service URLs, runtime proxy/auth, live-effect/operator-approval, billing, publication, and activation fields are not persisted. Omitted pricing_model defaults to per_call; omitted price defaults to 0.01 on native preview/create. Exact numeric/string zero is allowed, while malformed/non-decimal strings, positive-string underflow, alias conflict, and positive prices below 0.01 fail before effects. Returns a deployment packet with all live-effect flags set false.