Initial commit: Material Texture API service

- Go + Gin + GORM + PostgreSQL backend
- RESTful API for material management
- Docker deployment support
- Database partitioning for billion-scale data
- API documentation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

pkg/response/response.go

@@ -0,0 +1,72 @@
+package response
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+)
+
+type Response struct {
+	Code    int         `json:"code"`
+	Message string      `json:"message"`
+	Data    interface{} `json:"data,omitempty"`
+}
+
+type PagedData struct {
+	Items    interface{} `json:"items"`
+	Total    int64       `json:"total"`
+	Page     int         `json:"page"`
+	PageSize int         `json:"page_size"`
+}
+
+func Success(c *gin.Context, data interface{}) {
+	c.JSON(http.StatusOK, Response{
+		Code:    0,
+		Message: "success",
+		Data:    data,
+	})
+}
+
+func SuccessPaged(c *gin.Context, items interface{}, total int64, page, pageSize int) {
+	c.JSON(http.StatusOK, Response{
+		Code:    0,
+		Message: "success",
+		Data: PagedData{
+			Items:    items,
+			Total:    total,
+			Page:     page,
+			PageSize: pageSize,
+		},
+	})
+}
+
+func Created(c *gin.Context, data interface{}) {
+	c.JSON(http.StatusCreated, Response{
+		Code:    0,
+		Message: "created",
+		Data:    data,
+	})
+}
+
+func Error(c *gin.Context, statusCode int, message string) {
+	c.JSON(statusCode, Response{
+		Code:    statusCode,
+		Message: message,
+	})
+}
+
+func BadRequest(c *gin.Context, message string) {
+	Error(c, http.StatusBadRequest, message)
+}
+
+func NotFound(c *gin.Context, message string) {
+	Error(c, http.StatusNotFound, message)
+}
+
+func Unauthorized(c *gin.Context, message string) {
+	Error(c, http.StatusUnauthorized, message)
+}
+
+func InternalError(c *gin.Context, message string) {
+	Error(c, http.StatusInternalServerError, message)
+}