Bulk import custom locations from CSV on the Locations Admin page

Problem:

Customers managing custom locations on the Admin > Locations page have to add or edit each location individually. Customers who already maintain location lists in their own tools or in Ops & Safety Suite have no efficient way to bring those into Fleet Manager.

Desired outcome:

Customers can bulk import — and bulk update — their custom locations from a CSV file.

Proposed change:

Add a "Bulk Edit" button on the Admin > Locations page that opens a modal with: instructions, a CSV template download (with examples of each location type), an export of the current set, and a file picker for upload. Imports merge on lat/lon with imported values taking precedence on conflicting fields, after a file validity check and a skip/update/create preview with continue/abort.