-`DoJSONRequest[Req, Resp any](ctx, client, method, rawURL, body) (*Resp, error)` — free generic function that serialises `body` as JSON, constructs the `*http.Request` with `Content-Type: application/json`, and delegates response decoding to `DoJSON`. Complements `DoJSON` for POST/PUT/PATCH calls; use `DoJSON` for GET/DELETE where there is no request body.
### Changed
- Retry loop now handles HTTP 429 Too Many Requests: a 429 response triggers a retry (previously only `>= 500` did). When the server includes a `Retry-After` header with an integer seconds value, that duration is used as the retry delay for that attempt; otherwise the configured `BackOffDelay` applies.
-`logz` and `xerrors` dependencies bumped from v0.9.0 to v1.0.0.
### Unchanged
All other API (`Client`, `Config`, `DefaultConfig`, `New`, `NewWithDefaults`, `DoJSON`,
`MapStatusToError`) is API-compatible with v0.9.0.
-`DefaultConfig() Config`: returns a `Config` populated with all default values.
-`New(logger logz.Logger, cfg Config) Client`: constructs a client with a `gobreaker` circuit breaker wrapping an `avast/retry-go` retry loop. The circuit breaker trips after `CBThreshold` consecutive failures and resets after `CBTimeout`.
-`NewWithDefaults(logger logz.Logger) Client`: convenience constructor; equivalent to `New(logger, DefaultConfig())`.
- Retry behaviour: up to `MaxRetries` attempts with exponential backoff (`retry.BackOffDelay`). Only network errors and HTTP 5xx responses are retried; 4xx responses are not.
- Circuit breaker behaviour: the breaker wraps the full retry sequence, so one fully-exhausted retry sequence counts as one failure. State transitions are logged at `Warn` level with `name`, `from`, and `to` fields.
- Request ID propagation: `logz.GetRequestID(ctx)` is called on each attempt; if a request ID is present, it is forwarded as the `X-Request-ID` request header.
- Per-request structured logging: successful requests emit an `Info` log with `method`, `url`, `status`, and `latency` fields; failed individual attempts emit a `Debug` log.
- Error mapping on `Do`: open circuit → `ErrUnavailable`; post-retry HTTP error response → `MapStatusToError`; network/timeout error → `ErrInternal`.
-`DoJSON[T any](ctx context.Context, client Client, req *http.Request) (*T, error)`: generic free function that executes a request and decodes the JSON response body into `T`; returns `*T` on success and a xerrors-typed error for network failures, HTTP 4xx/5xx responses, unreadable bodies, or JSON decode failures.
- Dial timeout applied via a custom `net.Dialer` on the `http.Transport`, independent of the per-request `Timeout`.
### Design Notes
- The circuit breaker wraps the retry loop rather than individual attempts; a full set of exhausted retries registers as a single failure against the breaker threshold, preventing overly aggressive tripping.
-`DoJSON` is a free generic function rather than a method so it works with any `Client` implementation, including mocks, without requiring a concrete type.
- The module has no lifecycle (no `OnInit`/`OnStart`/`OnStop`) and does not depend on `launcher` or `health`; it is a stateless constructor suitable for use at any tier.
