Total Time is empty if grouping is not selected


### Discussed in https://github.com/almarklein/timetagger/discussions/551

<div type='discussions-op-text'>

<sup>Originally posted by **azzamsa** June 18, 2025</sup>
Hi, 

I find the total time is 0:0 if the grouping is not set (none). Is this expected?

![image](https://github.com/user-attachments/assets/9b151f31-3239-47f8-8c4b-1b03528b1ebf)

version: 25.06.1</div>