define expectations around case-sensitivity for coordinates

### Description

It is unclear if CD is handling case-sensitivity for coordinates consistently. This issue seeks to define what is expected and evaluate whether that is sufficient. This includes observations about how it is being handled by the various systems and how package managers expect case variations to be handled.

Start by reviewing the service's current handling of coordinate case-sensitivity, then compare observations across the various systems and the expectations of package managers. Define the expected behavior and assess whether the current behavior is sufficient; the issue names no files, tests, or entry points.

Written by the indexing model from the issue text.