feat: group admin users by role

admin_users.go

@@ -271,3 +271,69 @@ func (a *App) adminUpdateUser(c *gin.Context) {
 	a.audit(operator.ID, "user.update", "user", strconv.FormatUint(uint64(u.ID), 10), strings.Join(changes, ","))
 	c.JSON(200, u)
 }
+
+func (a *App) adminUserCredits(c *gin.Context) {
+	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.Status(400)
+		return
+	}
+	var account CreditAccount
+	if err := a.db.Where("user_id = ?", id).First(&account).Error; err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			c.JSON(404, gin.H{"error": "credit account not found"})
+			return
+		}
+		c.JSON(500, gin.H{"error": err.Error()})
+		return
+	}
+	var tasks int64
+	if err := a.db.Model(&Task{}).Where("user_id = ?", id).Count(&tasks).Error; err != nil {
+		c.JSON(500, gin.H{"error": err.Error()})
+		return
+	}
+	c.JSON(200, gin.H{"balance": account.Balance, "reserved": account.Reserved, "available": account.Balance - account.Reserved, "tasks": tasks})
+}
+
+func (a *App) adminAdjustCredits(c *gin.Context) {
+	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.Status(400)
+		return
+	}
+	var in struct {
+		Amount int64 `json:"amount"`
+	}
+	if c.BindJSON(&in) != nil || in.Amount == 0 {
+		c.JSON(400, gin.H{"error": "amount cannot be zero"})
+		return
+	}
+	operator := c.MustGet("user").(*User)
+	err = a.db.Transaction(func(tx *gorm.DB) error {
+		var account CreditAccount
+		if err := tx.Where("user_id = ?", id).First(&account).Error; err != nil {
+			return err
+		}
+		if in.Amount < 0 && account.Balance+in.Amount < account.Reserved {
+			return errors.New("cannot reduce balance below reserved credits")
+		}
+		account.Balance += in.Amount
+		if account.Balance < 0 {
+			return errors.New("insufficient balance")
+		}
+		if err := tx.Save(&account).Error; err != nil {
+			return err
+		}
+		typ, reason := "grant", "admin credit adjustment"
+		if in.Amount < 0 {
+			typ, reason = "admin_debit", "admin credit deduction"
+		}
+		return tx.Create(&CreditTransaction{UserID: uint(id), Type: typ, Amount: in.Amount, BalanceAfter: account.Balance, ReferenceType: "admin", ReferenceID: strconv.FormatUint(uint64(operator.ID), 10), Reason: reason}).Error
+	})
+	if err != nil {
+		c.JSON(400, gin.H{"error": err.Error()})
+		return
+	}
+	a.audit(operator.ID, "user.credits.adjust", "user", strconv.FormatUint(id, 10), "amount="+strconv.FormatInt(in.Amount, 10))
+	c.JSON(200, gin.H{"ok": true})
+}