Dev server can't differentiate between identically named folders with unique capitalization

Sorry for the somewhat spotty description, but the mechanics of how this works kinda elude me.

If you have two or more files permalinked to identically named folders, with different capitalization (e.g. "/ARTICLES/index.html" and "/articles/index.html"), the dev server appears to randomly pick one of the two folders to prefer. Afterwards, any link to any folder with that name, regardless of capitalization, will redirect to this chosen folder. This is not great since web hosts can tell the difference, so anyone who needs different capitalizations can't test it.

Additionally, the actual folder name shown in the search bar remains identical to the link, even if it's connected to a different folder, so anyone who accidentally capitalizes a folder name somewhere either won't realize they've made a mistake until much later, or will continually get the wrong page for no apparent reason.

Start by reproducing the issue with permalinked /ARTICLES/index.html and /articles/index.html, then trace the dev server's path resolution and redirect handling. Done means differently capitalized folders remain distinct, links resolve to the requested folder, and the displayed path matches the folder actually served.