更新项目文档，添加会话启动自检说明，强化 GORM 使用规范，确保数据操作遵循事务管理和预加载原则。修正多个处理函数以使用链式查询和数据验证，提升代码一致性和可维护性。

soul-api/internal/handler/wechat.go

@@ -93,18 +93,16 @@ func WechatPhoneLogin(c *gin.Context) {
 		user.Phone = &phone
 	}
 
-	var orderRows []struct {
-		ProductID string `gorm:"column:product_id"`
-	}
-	db.Raw(`
-		SELECT DISTINCT product_id FROM orders WHERE user_id = ? AND status = 'paid' AND product_type = 'section'
-	`, user.ID).Scan(&orderRows)
-	purchasedSections := []string{}
-	for _, row := range orderRows {
-		if row.ProductID != "" {
-			purchasedSections = append(purchasedSections, row.ProductID)
+	var purchasedSections []string
+	database.DB().Model(&model.Order{}).Where("user_id = ? AND status = ? AND product_type = ?", user.ID, "paid", "section").
+		Distinct("product_id").Pluck("product_id", &purchasedSections)
+	filtered := make([]string, 0, len(purchasedSections))
+	for _, s := range purchasedSections {
+		if s != "" {
+			filtered = append(filtered, s)
 		}
 	}
+	purchasedSections = filtered
 
 	responseUser := map[string]interface{}{
 		"id":               user.ID,