- Updated authentication to support OAuth2 Client Credentials and JWT with OIDC/JWKS verification.
- Added necessary claims for JWT, including `aud` and fallback for JWT metadata.
- Improved error response format and added additional claims for webhook events.
- Introduced new request body structure for creating send jobs, supporting both snake_case and camelCase.
- Implemented DevMockSenderWorker for simulating email sending during development.
- Integrated Amazon SES for email delivery, with bulk sending capabilities.
- Updated OpenAPI documentation to reflect changes in request and response schemas.
- Enhanced error handling and logging for better traceability.
