完善订单交接结账流程留痕

backend/internal/model/order.go

@@ -41,6 +41,8 @@ type RentalOrder struct {
 	GrowthPointsAwarded         int64          `gorm:"not null;default:0" json:"growth_points_awarded"`
 	GrowthPointsAwardedAt       *time.Time     `json:"growth_points_awarded_at"`
 	AccountSnapshot             datatypes.JSON `json:"account_snapshot"`
+	AccountSource               string         `gorm:"size:32;not null;default:'internal';index" json:"account_source"`
+	SourceChannel               string         `gorm:"size:32;not null;default:''" json:"source_channel"`
 	Status                      string         `gorm:"size:32;not null;default:'pending_payment'" json:"status"`
 	HandoffStatus               string         `gorm:"size:32;not null;default:'none'" json:"handoff_status"`
 	HandoffMode                 string         `gorm:"size:16;not null;default:'owner';index" json:"handoff_mode"`

backend/internal/model/process_event.go

@@ -0,0 +1,34 @@
+package model
+
+import (
+	"time"
+
+	"gorm.io/datatypes"
+)
+
+// ProcessEvent 是订单、提号等交易流程的不可变操作留痕。
+// 当前业务表仍保存当前状态；此表只追加，用于还原每一步由谁填写、修改和确认。
+type ProcessEvent struct {
+	ID             uint64         `gorm:"primaryKey" json:"id"`
+	BusinessType   string         `gorm:"size:32;not null;index:idx_process_event_business" json:"business_type"`
+	BusinessID     uint64         `gorm:"not null;index:idx_process_event_business" json:"business_id"`
+	Stage          string         `gorm:"size:32;not null;default:''" json:"stage"`
+	Action         string         `gorm:"size:64;not null" json:"action"`
+	ActorType      string         `gorm:"size:16;not null" json:"actor_type"`
+	ActorID        uint64         `gorm:"not null;default:0" json:"actor_id"`
+	ActorName      string         `gorm:"size:128;not null;default:''" json:"actor_name"`
+	TargetType     string         `gorm:"size:16;not null;default:''" json:"target_type"`
+	TargetID       *uint64        `json:"target_id,omitempty"`
+	TargetName     string         `gorm:"size:128;not null;default:''" json:"target_name"`
+	Content        string         `gorm:"type:text" json:"content"`
+	Reason         string         `gorm:"type:text" json:"reason"`
+	Payload        datatypes.JSON `gorm:"not null" json:"payload"`
+	AttachmentURLs datatypes.JSON `gorm:"column:attachment_urls;not null" json:"attachment_urls"`
+	StateBefore    datatypes.JSON `gorm:"column:state_before;not null" json:"state_before"`
+	StateAfter     datatypes.JSON `gorm:"column:state_after;not null" json:"state_after"`
+	CreatedAt      time.Time      `gorm:"index" json:"created_at"`
+}
+
+func (ProcessEvent) TableName() string {
+	return "process_events"
+}