feat: response headers functionality

[drish]

Summary by cubic

Adds a new Resend::Response wrapper that exposes HTTP response headers while keeping existing hash-style access fully compatible. Enables reading rate limit, request ID, and other metadata from API responses.

• New Features
  • All API calls now return Resend::Response, which behaves like a Hash and adds a headers accessor (keys normalized to lowercase).
  • Request extracts and normalizes headers; no breaking changes to existing usage.
  • Added headers example and tests for headers access and backward compatibility.

^{Written for commit e1ed093. Summary will update automatically on new commits.}

[cubic-dev-ai]

1 issue found across 6 files

Prompt for AI agents (all 1 issues)

Understand the root cause of the following 1 issues and fix them.


<file name="lib/resend/request.rb">

<violation number="1" location="lib/resend/request.rb:40">
Wrapping the HTTParty response with Resend::Response drops the entire response body because the wrapper only keeps data when it receives an actual Hash; HTTParty::Response fails the is_a?(Hash) check, so every call now returns an empty hash instead of the API payload. Ensure the wrapper receives the parsed hash data before instantiating it.</violation>
</file>

_{Reply to cubic to teach it or ask questions. Re-run a review with @cubic-dev-ai review this PR}