v0.1.3 — first-call configuration and safe error handling

First-call setup now fails locally when the API key is missing or blank, without sending a request. Non-empty keys continue unchanged to the API.

Export isDataApiError to safely narrow error payloads before reading their fields. README examples compile against the current public OpenAPI types, including responses whose JSON payload is unknown.

Validation: 37 unit tests pass, 1 credentialed live test skipped; typecheck, README examples and build pass. The packed archive was installed in a separate project and checked with mock responses and TypeScript. No authenticated API request was made for this release.

Not yet published to npm; use the prebuilt archive attached here. Keep the API key in backend configuration.