Snapshot the outbound wire and treat provider adapters like protocol code so…

Snapshot the outbound wire and treat provider adapters like protocol code so refactors can't silently drop parameters. Sentry’s Gemini trace bug shows the failure mode clearly, when a refactor re-proxied a chat object and the create-time config was stripped so traces no longer recorded temperature, max tokens or system instructions. Add outbound-payload contract tests and surface a typed capability map for each provider so you catch these regressions before they reach postmortems.