#241 chore: add release smoke-test script

Adds scripts/smoke_test_release.sh to smoke-test a released SDK version in a clean Docker container.

• Installs resend==<version> from PyPI (as a customer would)
• Runs the sending-focused examples/ files against a real API key
• Preflight checks Docker is installed and running

Usage: ./scripts/smoke_test_release.sh <version> <api_key> [example ...]

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Summary by cubic

Adds scripts/smoke_test_release.sh to validate a released resend SDK in a clean Docker container. Installs resend==<version> from PyPI and runs sending examples with a real API key, with clearer failure handling.

• New Features

  • Runs in python:3.12-slim; mounts examples/ and resources/ read-only; installs the SDK from PyPI.
  • Executes sending examples with RESEND_API_KEY; defaults: simple_email, with_attachments, with_b64_attachments, with_html_file_as_b64_attachment, with_inline_attachments, batch_email_send; prints a pass/fail summary; exits non-zero on any failure.
  • Preflight checks for Docker; supports PYTHON_IMAGE override and custom example lists. Usage: ./scripts/smoke_test_release.sh <version> <api_key> [example ...].

• Bug Fixes

  • Wraps docker run so failed examples don’t skip the summary; captures and reports the container exit code.
  • Fails fast with a clear error if pip install resend==<version> fails, avoiding running examples without the SDK.