feat: 对齐 Waffo 包年/永久结账与客户端席位 API

同步 OpsXShell 档位定价与 Waffo 商品映射，补齐 checkout/webhook/设备列表契约，便于桌面端购买与满席释放。

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/internal/controller/product/product_controller.go

@@ -1,6 +1,8 @@
 package product
 
 import (
+	"backend/internal/dto"
+	planservice "backend/internal/service/plan"
 	productservice "backend/internal/service/product"
 	"backend/utils"
 	"fmt"
@@ -13,13 +15,18 @@ import (
 
 // ProductController 产品控制器 // Logan.Li
 type ProductController struct {
-	svc *productservice.ProductService
-	db  *gorm.DB
+	svc     *productservice.ProductService
+	planSvc *planservice.PlanService
+	db      *gorm.DB
 }
 
 // NewProductController 创建控制器实例 // Logan.Li
 func NewProductController(db *gorm.DB) *ProductController {
-	return &ProductController{svc: productservice.NewProductService(db), db: db}
+	return &ProductController{
+		svc:     productservice.NewProductService(db),
+		planSvc: planservice.NewPlanService(db),
+		db:      db,
+	}
 }
 
 // List 产品列表 // Logan.Li
@@ -60,18 +67,28 @@ func (ctrl *ProductController) Get(c *gin.Context) {
 	c.JSON(http.StatusOK, gin.H{"code": 0, "data": product})
 }
 
+// GetByCode 按产品编码返回产品及上架计划（公开接口） // Logan.Li
+func (ctrl *ProductController) GetByCode(c *gin.Context) {
+	code := c.Param("code")
+	product, err := ctrl.svc.GetByCode(code)
+	if err != nil {
+		c.JSON(http.StatusOK, gin.H{"code": 404, "message": err.Error()})
+		return
+	}
+	plans, err := ctrl.planSvc.GetByProduct(product.ID)
+	if err != nil {
+		c.JSON(http.StatusOK, gin.H{"code": 1, "message": err.Error()})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"code": 0, "data": dto.ProductWithPlansResponse{
+		Product: *product,
+		Plans:   plans,
+	}})
+}
+
 // Create 创建产品 // Logan.Li
 func (ctrl *ProductController) Create(c *gin.Context) {
-	var req struct {
-		Name        string   `json:"name" binding:"required"`
-		Code        string   `json:"code" binding:"required"`
-		Version     string   `json:"version"`
-		Description string   `json:"description"`
-		Features    []string `json:"features"`
-		Price       float64  `json:"price"`
-		PriceModel  string   `json:"price_model"`
-		Status      *int     `json:"status"`
-	}
+	var req dto.ProductCreate
 	if err := c.ShouldBindJSON(&req); err != nil {
 		c.JSON(http.StatusBadRequest, gin.H{"code": 400, "message": "参数错误: " + err.Error()})
 		return
@@ -88,15 +105,7 @@ func (ctrl *ProductController) Create(c *gin.Context) {
 // Update 更新产品 // Logan.Li
 func (ctrl *ProductController) Update(c *gin.Context) {
 	id, _ := strconv.ParseUint(c.Param("id"), 10, 32)
-	var req struct {
-		Name        string   `json:"name"`
-		Version     string   `json:"version"`
-		Description string   `json:"description"`
-		Features    []string `json:"features"`
-		Price       *float64 `json:"price"`
-		PriceModel  string   `json:"price_model"`
-		Status      *int     `json:"status"`
-	}
+	var req dto.ProductUpdate
 	if err := c.ShouldBindJSON(&req); err != nil {
 		c.JSON(http.StatusBadRequest, gin.H{"code": 400, "message": "参数错误"})
 		return