支持 .env 配置，并完善源头对接文档与测试订单

- 增加 .env.example 与 godotenv 加载，start.sh 自动读环境变量
- 重写发给源头的开放接口对接文档
- 订单页支持创建测试订单（可直接已支付并复制店铺订单号）

backend/internal/config/config.go

@@ -2,7 +2,10 @@ package config
 
 import (
 	"os"
+	"path/filepath"
 	"strconv"
+
+	"github.com/joho/godotenv"
 )
 
 type Config struct {
@@ -18,7 +21,9 @@ type Config struct {
 	OpenSignSkew int64
 }
 
+// Load 加载配置：先尝试读取 .env，再读系统环境变量（已存在的系统环境变量优先级更高）
 func Load() *Config {
+	loadDotEnv()
 	return &Config{
 		Port:          getEnv("PORT", "8080"),
 		JWTSecret:     getEnv("JWT_SECRET", "affiliate-dash-dev-secret-change-me"),
@@ -30,6 +35,32 @@ func Load() *Config {
 	}
 }
 
+// loadDotEnv 依次尝试常见路径，不覆盖已有环境变量
+func loadDotEnv() {
+	var paths []string
+	if wd, err := os.Getwd(); err == nil {
+		paths = append(paths,
+			filepath.Join(wd, ".env"),
+			filepath.Join(wd, "..", ".env"),       // 在 backend/ 下启动时读仓库根 .env
+			filepath.Join(wd, "backend", ".env"),  // 在仓库根启动时
+		)
+	}
+	paths = append(paths, ".env")
+
+	seen := map[string]struct{}{}
+	for _, p := range paths {
+		abs, err := filepath.Abs(p)
+		if err != nil {
+			continue
+		}
+		if _, ok := seen[abs]; ok {
+			continue
+		}
+		seen[abs] = struct{}{}
+		_ = godotenv.Load(abs) // 忽略不存在；不覆盖已在环境中的变量
+	}
+}
+
 func getEnv(key, def string) string {
 	if v := os.Getenv(key); v != "" {
 		return v

backend/internal/handler/order.go

@@ -45,30 +45,43 @@ func (h *OrderHandler) List(c *gin.Context) {
 }
 
 type createOrderReq struct {
-	SkinID    uint   `json:"skin_id" binding:"required"`
-	BuyerName string `json:"buyer_name"`
-	Remark    string `json:"remark"`
+	SkinID         uint   `json:"skin_id" binding:"required"`
+	BuyerName      string `json:"buyer_name"`
+	Remark         string `json:"remark"`
+	Status         string `json:"status"`          // 管理员可传 paid 直接可发货
+	DistributorID  *uint  `json:"distributor_id"` // 管理员可指定分销商
 }
 
 func (h *OrderHandler) Create(c *gin.Context) {
 	var req createOrderReq
 	if err := c.ShouldBindJSON(&req); err != nil {
-		response.BadRequest(c, "参数错误")
+		response.BadRequest(c, "参数错误：请选择商品")
 		return
 	}
 	distributorID := middleware.GetUserID(c)
-	// 管理员可指定分销商
+	status := ""
+	// 管理员可指定分销商、创建已支付测试单
 	if middleware.GetRole(c) == model.RoleAdmin {
+		if req.DistributorID != nil && *req.DistributorID > 0 {
+			distributorID = *req.DistributorID
+		}
 		if d := c.Query("distributor_id"); d != "" {
 			id, _ := strconv.ParseUint(d, 10, 64)
 			distributorID = uint(id)
 		}
+		if req.Status == model.OrderStatusPaid {
+			status = model.OrderStatusPaid
+		}
+	}
+	if req.BuyerName == "" {
+		req.BuyerName = "测试买家"
 	}
 	order, err := h.svc.Create(service.CreateOrderInput{
 		SkinID:        req.SkinID,
 		DistributorID: distributorID,
 		BuyerName:     req.BuyerName,
 		Remark:        req.Remark,
+		Status:        status,
 	})
 	if err != nil {
 		response.BadRequest(c, err.Error())

backend/internal/service/order.go

@@ -31,6 +31,8 @@ type CreateOrderInput struct {
 	DistributorID uint
 	BuyerName     string
 	Remark        string
+	// Status 可选：pending（默认）/ paid（联调测试可直接创建可发货订单）
+	Status string
 }
 
 func (s *OrderService) List(q OrderListQuery) ([]model.Order, int64, error) {
@@ -71,6 +73,11 @@ func (s *OrderService) Create(in CreateOrderInput) (*model.Order, error) {
 		return nil, errors.New("库存不足")
 	}
 
+	status := model.OrderStatusPending
+	if in.Status == model.OrderStatusPaid {
+		status = model.OrderStatusPaid
+	}
+
 	order := &model.Order{
 		OrderNo:       generateOrderNo(),
 		SkinID:        in.SkinID,
@@ -78,7 +85,7 @@ func (s *OrderService) Create(in CreateOrderInput) (*model.Order, error) {
 		BuyerName:     in.BuyerName,
 		Amount:        skin.Price,
 		CommissionAmt: skin.Price * skin.Commission,
-		Status:        model.OrderStatusPending,
+		Status:        status,
 		Remark:        in.Remark,
 	}
 
@@ -99,6 +106,8 @@ func (s *OrderService) Create(in CreateOrderInput) (*model.Order, error) {
 	if err != nil {
 		return nil, err
 	}
+	// 带回商品信息，方便前端展示 sku / 订单号联调
+	_ = s.db.Preload("Skin").First(order, order.ID).Error
 	return order, nil
 }