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>

internal/middleware/auth.go

@@ -0,0 +1,32 @@
+package middleware
+
+import (
+	"material_texture/pkg/response"
+
+	"github.com/gin-gonic/gin"
+)
+
+const (
+	HeaderAPIToken = "X-API-Token"
+)
+
+// TokenAuth 简单Token认证中间件
+func TokenAuth(expectedToken string) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		token := c.GetHeader(HeaderAPIToken)
+
+		if token == "" {
+			response.Unauthorized(c, "missing API token")
+			c.Abort()
+			return
+		}
+
+		if token != expectedToken {
+			response.Unauthorized(c, "invalid API token")
+			c.Abort()
+			return
+		}
+
+		c.Next()
+	}
+}