odd commit date in 001169

```
(dandisets-2) dandi@drogon:/mnt/backup/dandi/dandisets/001169$ git log --format=fuller | head -n 25
commit c0635fd963
Author: DANDI User
AuthorDate: 2026 Aug 25 15:09:57 -0400
Commit: DANDI Team
CommitDate: 2026 Aug 27 01:49:12 -0400

[backups2datalad] dandiset.yaml updated

commit 8605dc5859
Author: DANDI User
AuthorDate: 2024 Nov 04 14:29:21 -0500
Commit: DANDI Team
CommitDate: 2026 Aug 27 01:20:00 -0400

[backups2datalad] 10240 files added

commit f5afb2aed1
Author: DANDI User
AuthorDate: 2026 May 28 06:03:49 -0400
Commit: DANDI Team
CommitDate: 2026 May 28 06:17:18 -0400

[backups2datalad] Only some metadata updates

```

so somehow for that 8605dc5859 overall deduced date became back into 2024 Nov after prior one was in 2026 May 28 ... That date is content driven but it feels that may be it is lacking 'max' with dandiset metadata modification date or smth like that? although also unclear how still we would get 2024 for that addition of many files

Start by tracing the code that derives commit dates while processing dandiset 001169, using commits c0635fd963, 8605dc5859, and f5afb2aed1 as reproduction data. Check how content dates are combined with metadata modification dates and verify the resulting history preserves the expected chronological values. Done means the anomalous 2024 date is explained or corrected and the behavior is covered by an appropriate test or reproducible check.

Written by the indexing model from the issue text.