fix: logout requires both device_id and instance_id

Only clear specific instance on specific device
Remove cross-device and all-instances clearing

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend/internal/router/app/user.go

@@ -43,17 +43,11 @@ func handleAppLogout(c *gin.Context) {
 	}
 
 	var req struct {
-		DeviceID   string `json:"device_id"`
+		DeviceID   string `json:"device_id" binding:"required"`
-		InstanceID string `json:"instance_id"`
+		InstanceID string `json:"instance_id" binding:"required"`
 	}
 	if err := c.ShouldBindJSON(&req); err != nil {
-		response.Error(c, 400, "参数错误")
+		response.Error(c, 400, "device_id 和 instance_id 为必填参数")
-		return
-	}
-
-	// 只有 device_id 没有 instance_id 时提示错误
-	if req.DeviceID != "" && req.InstanceID == "" {
-		response.Error(c, 400, "缺少 instance_id 参数")
 		return
 	}
 
@@ -69,43 +63,25 @@ func handleAppLogout(c *gin.Context) {
 		return
 	}
 
-	deviceIDs := make([]uint, len(devices))
+	// 查找指定设备
-	for i, d := range devices {
+	var targetDeviceID uint
-		deviceIDs[i] = d.ID
+	for _, d := range devices {
+		if d.DeviceID == req.DeviceID {
+			targetDeviceID = d.ID
+			break
+		}
 	}
 
-	var deletedCount int64
+	if targetDeviceID == 0 {
-
+		response.Error(c, 404, "设备不存在")
-	if req.InstanceID != "" && req.DeviceID != "" {
+		return
-		// 清除指定设备的指定实例
-		var targetDeviceID uint
-		for _, d := range devices {
-			if d.DeviceID == req.DeviceID {
-				targetDeviceID = d.ID
-				break
-			}
-		}
-
-		if targetDeviceID == 0 {
-			response.Error(c, 404, "设备不存在")
-			return
-		}
-
-		result := database.DB.Where("device_id = ? AND instance_id = ?", targetDeviceID, req.InstanceID).Delete(&model.DeviceSession{})
-		deletedCount = result.RowsAffected
-		log.Printf("[INFO] Logout: deleted session for device %s, instance %s, count %d", req.DeviceID, req.InstanceID, deletedCount)
-	} else if req.InstanceID != "" {
-		// 清除指定实例（跨设备）
-		result := database.DB.Where("device_id IN ? AND instance_id = ?", deviceIDs, req.InstanceID).Delete(&model.DeviceSession{})
-		deletedCount = result.RowsAffected
-		log.Printf("[INFO] Logout: deleted instance %s across all devices, count %d", req.InstanceID, deletedCount)
-	} else {
-		// 清除该用户所有实例
-		result := database.DB.Where("device_id IN ?", deviceIDs).Delete(&model.DeviceSession{})
-		deletedCount = result.RowsAffected
-		log.Printf("[INFO] Logout: deleted all sessions for user %d, count %d", userID, deletedCount)
 	}
 
+	// 清除指定实例
+	result := database.DB.Where("device_id = ? AND instance_id = ?", targetDeviceID, req.InstanceID).Delete(&model.DeviceSession{})
+	deletedCount := result.RowsAffected
+	log.Printf("[INFO] Logout: user %d, device %s, instance %s, deleted %d", userID, req.DeviceID, req.InstanceID, deletedCount)
+
 	service.LogVerification(c, &app.ID, uintPtr(userID.(uint)), "logout", fmt.Sprintf("用户登出，清除 %d 个实例", deletedCount), req.DeviceID, nil)
 
 	response.Success(c, gin.H{