Pages/Content with `_` does not work

Example from Slack: https://cq-dev.slack.com/archives/C08MJQ0Q3GA/p1756110800717299

* https://content.da.live/wsu-do/library/researchers/openaccessfeesupport/.open-access-article-processing/ERA_2018_Submission_Guidelines.pdf (gives 404)
* https://admin.da.live/source/wsu-do/library/researchers/openaccessfeesupport/.open-access-article-processing/ERA_2018_Submission_Guidelines.pdf > works

content.da.live tries to fetch `https://admin.da.live/source/wsu-do/library/researchers/openaccessfeesupport/.open-access-article-processing/era2018submissionguidelines.pdf` this gets sanitised in https://github.com/adobe/da-content/blob/c491d2295cb0b4338ae99a87e403c49f00a75ea8/src/storage/admin.js#L44-L47

Sanitisation in Helix us different, `_` gets a `-`. See https://www.aem.live/docs/limits#document-naming-restrictions

Start at src/storage/admin.js, especially lines 44-47, and reproduce the two content.da.live and admin.da.live URLs from the issue. Compare the sanitization behavior with the Helix document-naming restrictions; done means paths containing underscores resolve consistently instead of returning a 404.

Written by the indexing model from the issue text.