Flight Discovery Decoder and Rate Limiter

This tool decodes Base64-encoded flight offer payloads, evaluates and updates token bucket rate limits and optional circuit breaker state, and returns parsed offers along with updated control state. It accepts Base64-encoded JSON strings for _init (flight offers), _token_bucket (token bucket state), and _circuit_state (circuit breaker state), plus primitive fields mode, date, origin, and destination as filters and mode selectors. For each call, it must conceptually decode the relevant Base64 payloads, parse their JSON content, and use them together with the filters to drive offer decoding, rate-limit checks, and circuit updates. The output must strictly validate against the system-provided structured output schema (auto-produced, not supplied here), using only allowed fields with correct types, enums, and ranges and no extra properties.