added auth service to go backend

backend-go/internal/application/services/dto/auth_dto.go

@@ -0,0 +1,18 @@
+package dto
+
+// TokenResponseDTO represents the response for a token generation or validation.
+type TokenResponseDTO struct {
+	Token  string `json:"token"`
+	UserID string `json:"user_id"`
+}
+
+// TokenRequestDTO represents a request for operations involving tokens.
+type TokenRequestDTO struct {
+	Token string `json:"token"`
+}
+
+// LoginRequestDTO represents the login request.
+type LoginRequestDTO struct {
+	Email    string `json:"email"`
+	Password string `json:"password"`
+}