Renders URL/headers/body with Mustache, optionally HMAC-signs the body (X-Cameleer-Signature), supports POST/PUT/PATCH, classifies 2xx/4xx/5xx into DELIVERED/FAILED/retry. 8 WireMock-backed IT tests including HTTPS TRUST_ALL against WireMock self-signed cert. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>