Stop sometimes ignores digits

```
❯ timew start 24hours ago someth
Note: 'someth' is a new tag.
Tracking someth
Started 2020-11-25T13:47:32
Current 26T13:47:32
Total 24:00:00
❯ timew stop 60
The current interval does not have the '60' tag.
❯ timew stop 61
Recorded someth
Started 2020-11-25T13:47:32
Ended 26T13:46:39
Total 23:59:07
❯ timew continue
Tracking someth
Started 2020-11-26T13:47:48
Current 48
Total 0:00:00
❯ timew stop t
The current interval does not have the 't' tag.
❯ timew stop 1000
The end of a date range must be after the start.
❯ timew stop 999
The end of a date range must be after the start.
❯ timew stop 100
The end of a date range must be after the start.
❯ timew stop 000
Recorded someth
Started 2020-11-26T13:47:48
Ended 48:35
Total 0:00:47
```

Sometimes it has also ignored the `100` - it simply stopped as if there were no third argument

Reproduce the reported cases with the `timew stop` command, especially numeric arguments such as `60`, `61`, `100`, `999`, `1000`, and `000`. Trace the stop-command argument parsing and date-range validation; done means numeric tags are handled consistently and valid stop arguments no longer get ignored or produce incorrect range errors.

Written by the indexing model from the issue text.