add model identities and restore httpx router

backend/internal/models/ai_call_log.go

@@ -3,14 +3,16 @@ package models
 import "time"
 
 type SenlinAgentAICallLog struct {
-	ID          uint   `gorm:"primaryKey"`
-	UserID      uint   `gorm:"index;not null"`
-	Provider    string `gorm:"not null"`
-	UsedKeyType string `gorm:"not null"`
-	Action      string `gorm:"not null"`
-	Status      string `gorm:"not null"`
-	Error       string
-	CreatedAt   time.Time
+	ID           uint   `gorm:"primaryKey"`
+	Identity     string `gorm:"type:char(36);uniqueIndex"`
+	UserID       uint   `gorm:"index;not null"`
+	UserIdentity string `gorm:"type:char(36);index"`
+	Provider     string `gorm:"not null"`
+	UsedKeyType  string `gorm:"not null"`
+	Action       string `gorm:"not null"`
+	Status       string `gorm:"not null"`
+	Error        string
+	CreatedAt    time.Time
 }
 
 func (SenlinAgentAICallLog) TableName() string {