feat: Add user registration endpoint with JWT token generation and update API documentation

backend/internal/api/handlers/user_handler.go

@@ -261,6 +261,52 @@ func (h *UserHandler) Login(c *gin.Context) {
 	utils.SuccessResponse(c, http.StatusOK, tokenDTO)
 }
 
+// Register handles POST /auth/register
+//
+//	@Summary		Register
+//	@Description	Register a new user and get a JWT token
+//	@Tags			auth
+//	@Accept			json
+//	@Produce		json
+//	@Param			user	body		dto.UserCreateDto	true	"User data"
+//	@Success		201		{object}	utils.Response{data=dto.TokenDto}
+//	@Failure		400		{object}	utils.Response{error=utils.ErrorInfo}
+//	@Failure		500		{object}	utils.Response{error=utils.ErrorInfo}
+//	@Router			/auth/register [post]
+func (h *UserHandler) Register(c *gin.Context) {
+	// Parse request body
+	var userCreateDTO dto.UserCreateDto
+	if err := c.ShouldBindJSON(&userCreateDTO); err != nil {
+		utils.BadRequestResponse(c, "Invalid request body: "+err.Error())
+		return
+	}
+
+	// Convert DTO to model
+	userCreate := convertCreateDTOToModel(userCreateDTO)
+
+	// Create user in the database
+	user, err := models.CreateUser(c.Request.Context(), userCreate)
+	if err != nil {
+		utils.InternalErrorResponse(c, "Error creating user: "+err.Error())
+		return
+	}
+
+	// Generate JWT token
+	token, err := middleware.GenerateToken(user)
+	if err != nil {
+		utils.InternalErrorResponse(c, "Error generating token: "+err.Error())
+		return
+	}
+
+	// Return token
+	tokenDTO := dto.TokenDto{
+		Token: token,
+		User:  convertUserToDTO(user),
+	}
+
+	utils.SuccessResponse(c, http.StatusCreated, tokenDTO)
+}
+
 // GetCurrentUser handles GET /auth/me
 //
 //	@Summary		Get current user