UI: sort by modified time in Job allocation view wrong

### Nomad version

Nomad v1.10.0
BuildDate 2025-04-09T16:40:54Z
Revision e26a2bd

### Operating system and Environment details

Ubuntu 24.04.2 LTS
aarch64

### Issue

When sorting by modified time in the job allocation view in the web UI, it does not use the same time as used in the table.

### Reproduction steps

I don't know, but I was rescheduling/reallocating jobs quite a bit when I noticed it

#### Expected Result

The sort order to match the value in the column.

#### Actual Result

See screenshot

### Nomad client logs

```
Allocations
ID Node ID Task Group Version Desired Status Created Modified
a3e5155d 8d347a49 mads-test 3 run running 20m41s ago 20m13s ago
f1e97b89 55b93f68 mads-test 3 run running 20m43s ago 20m21s ago
3d97c300 74995fa4 mads-test 3 stop complete 25m29s ago 20m42s ago
7c4e4942 55b93f68 mads-test 3 stop complete 36m13s ago 25m28s ago
63b9d8f4 f36dd73a mads-test 3 stop complete 36m35s ago 20m41s ago
63a88bcf 74995fa4 mads-test 3 stop complete 38m19s ago 36m13s ago
f9e7ed0a 55f86255 mads-test 3 stop complete 40m27s ago 38m18s ago
5086d8ee 74995fa4 mads-test 3 stop complete 40m55s ago 36m35s ago
cde8d65c 55b93f68 mads-test 3 stop complete 48m58s ago 40m26s ago
c394e0d3 55f86255 mads-test 3 stop complete 2h11m ago 48m58s ago
a91e5895 55b93f68 mads-test 3 stop complete 2h11m ago 40m54s ago
```


Start with the Job allocation view in Nomad's web UI and inspect how the displayed Modified value differs from the value used for sorting. Reproduce the mismatch with allocation data like the report's table, then make the sort order match the Modified column and verify both ascending and descending behavior.

Written by the indexing model from the issue text.