Ente Auth on Windows - proxy support

[ChristopherW]

Using Ente Auth in a corporate environment requires that I use the organisation's proxy servers (HTTP CONNECT). The proxy servers are defined both in the Internet Settings scope, used by browsers, and also at the OS level in the WinHTTP netsh proxy configuration.

Wiresharking the connection attempt, I can see Auth always attempts to directly contact ente.io and then api.ente.io, regardless of OS proxy settings, resulting in the loading spinner, a short period of inactivity then a timeout with this error:

I believe Auth should be made proxy-aware, not just attempt to always assume it can directly connect.