refactor: 重构项目结构，迁移后端至 mengyastore-backend-go，新增 Java 后端、前端功能更新及部署文档

mengyastore-backend-go/internal/handlers/admin.go

@@ -0,0 +1,41 @@
+package handlers
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+
+	"mengyastore-backend/internal/config"
+	"mengyastore-backend/internal/storage"
+)
+
+// AdminHandler 持有所有管理员路由所需的依赖。
+type AdminHandler struct {
+	store      *storage.ProductStore
+	cfg        *config.Config
+	siteStore  *storage.SiteStore
+	orderStore *storage.OrderStore
+	chatStore  *storage.ChatStore
+}
+
+func NewAdminHandler(store *storage.ProductStore, cfg *config.Config, siteStore *storage.SiteStore, orderStore *storage.OrderStore, chatStore *storage.ChatStore) *AdminHandler {
+	return &AdminHandler{store: store, cfg: cfg, siteStore: siteStore, orderStore: orderStore, chatStore: chatStore}
+}
+
+// requireAdmin 校验管理员令牌。
+// 优先级：X-Admin-Token 请求头 > Authorization 请求头 > ?token 查询参数（旧版兼容）。
+func (h *AdminHandler) requireAdmin(c *gin.Context) bool {
+	token := c.GetHeader("X-Admin-Token")
+	if token == "" {
+		token = c.GetHeader("Authorization")
+	}
+	if token == "" {
+		// 兼容旧版客户端的 URL 查询参数回退
+		token = c.Query("token")
+	}
+	if token != "" && token == h.cfg.AdminToken {
+		return true
+	}
+	c.JSON(http.StatusUnauthorized, gin.H{"error": "unauthorized"})
+	return false
+}