[Bug] PathLib:expand() strips $ from filenames that aren't environment variables

[nsinotov]

Description

PathLib:expand() in lua/diffview/path.lua:299 strips the $ prefix from path segments that start with $ but aren't valid environment variables.

Actual behavior

The diff pane for affected files shows the entire file as added (green) on one side and a null buffer on the other, because the local file buffer is opened at a non-existent path.

Steps to reproduce

For reproducing have a file with $ in the name — e.g. a Remix route like routes/($accountId)/entities/$id.tsx

Neovim version

Neovim 0.11.6

Operating system and version

macOS

[dlyongemallo]

@nsinotov This seems to be a dup of #556 which is fixed by #557. The fix has been merged in my fork.

[nsinotov]

@dlyongemallo thank you!