Adding work with track during active tracking with exclusions

I needed to add some past evening work with the track command in the middle of an ongoing task that was limited with exclusions.

This is what happened.
```
define exclusions:
monday = <6:30 12:00-12:30 >15:00
tuesday = <6:30 12:00-12:30 >15:00
wednesday = <6:30 12:00-12:30 >15:00
thursday = <6:30 12:00-12:30 >15:00
friday = <6:30 12:00-12:30 >15:00
saturday = >0:00
sunday = >0:00

❯ timew s :week

Wk Date Day Tags Start End Time Total
W17 2022-04-25 Mon Things 6:30:00 12:00:00 5:30:00
Things 12:30:00 15:00:00 2:30:00 8:00:00
W17 2022-04-26 Tue Things 6:30:00 12:00:00 5:30:00
Things 12:30:00 15:00:00 2:30:00 8:00:00
W17 2022-04-27 Wed Things 6:30:00 12:00:00 5:30:00
Things 12:30:00 15:00:00 2:30:00 8:00:00
W17 2022-04-28 Thu Things 6:30:00 - 0:57:23 0:57:23

24:57:23

> timew track 2022-04-27T19:00 - 2022-04-27T23:00 "Other thing"

❯ timew s :week

Wk Date Day Tags Start End Time Total
W17 2022-04-25 Mon Thing 6:30:00 - 17:30:00 17:30:00
W17 2022-04-26 Tue Thing 0:00:00 - 24:00:00 24:00:00
W17 2022-04-27 Wed Thing 0:00:00 - 24:00:00
Other thing 19:00:00 23:00:00 4:00:00 28:00:00
W17 2022-04-28 Thu Thing 0:00:00 - 7:27:59 7:27:59

76:57:59
```

I would expect the result to be like this.
```
Wk Date Day Tags Start End Time Total
W17 2022-04-25 Mon Things 6:30:00 12:00:00 5:30:00
Things 12:30:00 15:00:00 2:30:00 8:00:00
W17 2022-04-26 Tue Things 6:30:00 12:00:00 5:30:00
Things 12:30:00 15:00:00 2:30:00 8:00:00
W17 2022-04-27 Wed Things 6:30:00 12:00:00 5:30:00
Things 12:30:00 15:00:00 2:30:00 8:00:00
Other thing 19:00:00 23:00:00 4:00:00 28:00:00
W17 2022-04-28 Thu Things 6:30:00 - 0:57:23 0:57:23

24:57:23
```

Start by reproducing the issue with the shown exclusions, `timew track` command, and `timew s :week` reports. Trace the track command's handling of an interval added during active tracking and compare the resulting report with the expected output. Done means adding past work preserves existing tracked intervals and exclusion boundaries without inflating other days' totals.

Written by the indexing model from the issue text.