v0.1.0 of tsdtech_client_sdk

SDK Dart para integração com a plataforma TsdTech de pagamentos. Changelog excerpt: ### Added - Initial SDK foundation for TsdTech client integration - BaseApi: Static HTTP client using Dio for making API requests - IntraApi: Base class for intra-service API communication - ValueResult: Result type for handling success/failure responses - VouchersService: Client voucher management (list, retrieve) - CheckoutsService: Payment checkout flow (calculate, create, PIX status) - AuthServiceClientUser: Client user authentication (login, signup) - OrdersService: Client order management[...]