Render a correctly sized passport photograph

Send the image as the request body with a `Content-Type` of `image/jpeg` or `image/png`, and name the destination in the query. Returns the cropped, background-replaced photograph as base64.

**Stateless.** The bytes are read into memory, passed to the rendering service, and returned. Nothing is written to storage and no row is created, which is deliberate: a passport photograph is the one document whose retention raises the hardest questions in this product.

**`compliant` is always `false`.** The pipeline verifies exactly one thing for itself, that a single face was detected. Everything else an immigration officer looks at is unmeasured and is listed under `human_review`, never as a passing check. A `200` carrying `errors` means the photograph was seen and could not be used, which is a different outcome from a failure to reach the service.