- Introduced `validateSignup` endpoint in AuthController for customer number validation during signup.
- Added `healthCheck` method in AuthService to verify service integrations and database connectivity.
- Implemented `getPaymentMethods`, `getPaymentGateways`, and `refreshPaymentMethods` endpoints in InvoicesController for managing user payment options.
- Enhanced InvoicesService with methods to invalidate payment methods cache and improved error handling.
- Updated currency handling across various services and components to reflect JPY as the default currency.
- Added new dependencies in package.json for ESLint configuration.
- Introduced email configuration for both development and production environments in `.env.dev.example` and `.env.production.example`.
- Added SendGrid API key and email settings to support password reset and welcome emails.
- Implemented password reset and request password reset endpoints in the AuthController.
- Enhanced signup form to include additional fields such as Customer Number, address, nationality, date of birth, and gender.
- Updated various services and controllers to integrate email functionality and handle new user data.
- Refactored logging and error handling for improved clarity and maintainability.
- Adjusted Docker configuration for production deployment.
