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/public.go

@@ -0,0 +1,62 @@
+package handlers
+
+import (
+	"net/http"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+
+	"mengyastore-backend/internal/models"
+	"mengyastore-backend/internal/storage"
+)
+
+type PublicHandler struct {
+	store *storage.ProductStore
+}
+
+func NewPublicHandler(store *storage.ProductStore) *PublicHandler {
+	return &PublicHandler{store: store}
+}
+
+func (h *PublicHandler) ListProducts(c *gin.Context) {
+	items, err := h.store.ListActive()
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"data": sanitizeForPublic(items)})
+}
+
+func (h *PublicHandler) RecordProductView(c *gin.Context) {
+	id := c.Param("id")
+	fingerprint := buildViewerFingerprint(c)
+	product, counted, err := h.store.IncrementView(id, fingerprint)
+	if err != nil {
+		c.JSON(http.StatusNotFound, gin.H{"error": err.Error()})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{
+		"data": gin.H{
+			"id":        product.ID,
+			"viewCount": product.ViewCount,
+			"counted":   counted,
+		},
+	})
+}
+
+func buildViewerFingerprint(c *gin.Context) string {
+	clientIP := strings.TrimSpace(c.ClientIP())
+	userAgent := strings.TrimSpace(c.GetHeader("User-Agent"))
+	language := strings.TrimSpace(c.GetHeader("Accept-Language"))
+	return clientIP + "|" + userAgent + "|" + language
+}
+
+func sanitizeForPublic(items []models.Product) []models.Product {
+	out := make([]models.Product, len(items))
+	for i, item := range items {
+		item.Codes = nil
+		out[i] = item
+	}
+	return out
+}
+