[Feature] Manage Location view: add indicator in timeline of items missing location

I have searched the existing feature requests, both open and closed, to make sure this is not a duplicate request.

• Yes

The feature

In Utilities > Manage location, I suggest adding visual markers in the timeline strip to show where on it are items with missing location. Like this:
<img width="422" height="1282" alt="2026-09-12 17_16_56" src=" />
It's similar to what you see in VS Code when doing a compare of files and the markers show where the differences are. This change would make it much easier to check and find items that need their location fixed.

Platform

• Server
• Web
• Mobile