fix: 按评审报告止血支付漏洞并加固授权链路

废除浏览器回跳自助结算，通用 webhook 强制密钥鉴权，Waffo 支持验签与未知事件忽略；重构订单状态机/激活占座/SQLite WAL，并补备份、readyz、限流与前端导出/登录页安全修复。

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

backend/internal/model/customer.go

@@ -11,7 +11,7 @@ type Customer struct {
 	ID        uint           `json:"id" gorm:"primaryKey"`
 	Name      string         `json:"name" gorm:"size:100;not null"`
 	Company   string         `json:"company" gorm:"size:200"`
-	Email     string         `json:"email" gorm:"size:100;index"`
+	Email     string         `json:"email" gorm:"size:100;uniqueIndex"`
 	Phone     string         `json:"phone" gorm:"size:20"`
 	Address   string         `json:"address" gorm:"size:500"`
 	Notes     string         `json:"notes" gorm:"type:text"`

backend/internal/model/entitlement.go

@@ -5,16 +5,16 @@ import "time"
 // CustomerEntitlement 客户权益记录（防重复购买的核心表） // Logan.Li
 type CustomerEntitlement struct {
 	ID         uint       `json:"id" gorm:"primaryKey"`
-	CustomerID uint       `json:"customer_id"`
+	CustomerID uint       `json:"customer_id" gorm:"uniqueIndex:idx_ent_cust_prod,priority:1"`
 	Customer   Customer   `json:"customer,omitempty" gorm:"foreignKey:CustomerID"`
-	ProductID  uint       `json:"product_id"`
+	ProductID  uint       `json:"product_id" gorm:"uniqueIndex:idx_ent_cust_prod,priority:2"`
 	Product    Product    `json:"product,omitempty" gorm:"foreignKey:ProductID"`
 	PlanID     uint       `json:"plan_id"`
 	Plan       Plan       `json:"plan,omitempty" gorm:"foreignKey:PlanID"`
 	LicenseID  uint       `json:"license_id"`
 	LicenseKey string     `json:"license_key" gorm:"size:100"`
-	PlanType   string     `json:"plan_type" gorm:"size:50"`                   // perpetual / monthly / yearly / lifetime
-	Status     string     `json:"status" gorm:"size:20;default:'active'"`     // active / expired / revoked
+	PlanType   string     `json:"plan_type" gorm:"size:50"`               // perpetual / monthly / yearly / lifetime
+	Status     string     `json:"status" gorm:"size:20;default:'active'"` // active / expired / revoked
 	ValidFrom  time.Time  `json:"valid_from"`
 	ValidUntil *time.Time `json:"valid_until,omitempty"` // 买断/永久为 null
 	Renewable  bool       `json:"renewable" gorm:"default:true"` // 订阅到期后是否可续费

backend/internal/model/license.go

@@ -62,9 +62,9 @@ func (License) TableName() string {
 // Activation 激活记录模型（机器绑定） // Logan.Li
 type Activation struct {
 	ID          uint       `json:"id" gorm:"primaryKey"`
-	LicenseID   uint       `json:"license_id"`
+	LicenseID   uint       `json:"license_id" gorm:"uniqueIndex:idx_lic_device,priority:1"`
 	License     License    `json:"license,omitempty" gorm:"foreignKey:LicenseID"`
-	DeviceID    string     `json:"device_id" gorm:"size:100"`
+	DeviceID    string     `json:"device_id" gorm:"size:100;uniqueIndex:idx_lic_device,priority:2"`
 	DeviceName  string     `json:"device_name" gorm:"size:200"`
 	DeviceInfo  string     `json:"device_info" gorm:"type:text"` // JSON 格式存储设备信息
 	IP          string     `json:"ip" gorm:"size:50"`

backend/internal/model/order.go

@@ -18,7 +18,7 @@ type Order struct {
 	Status         string     `json:"status" gorm:"size:20;default:'pending'"` // pending / paid / failed / refunded / cancelled
 	PaymentMethod  string     `json:"payment_method" gorm:"size:50"`           // paddle / stripe / creem / waffo / alipay / wechat
 	PaymentGateway string     `json:"payment_gateway" gorm:"size:50"`
-	GatewayOrderNo string     `json:"gateway_order_no" gorm:"size:200"`
+	GatewayOrderNo string     `json:"gateway_order_no" gorm:"size:200;index"`
 	PaidAt         *time.Time `json:"paid_at,omitempty"`
 	RefundAt       *time.Time `json:"refund_at,omitempty"`
 	ClientIP       string     `json:"client_ip" gorm:"size:50"`