Feature Request: Support macOS

### Is your feature request related to a problem? Please describe.

Would it be hard to make this work on macOS as well? You already support FreeBSD, so I hope so!

I realize this is primarily for Linux, and macOS already has a desktop client, but there are multiple advantages of your tool over the Microsoft-provided software that would help on macOS as well.

A few examples:
- direct syncing (doesn't depend on macOS FileProvider)
- alternative modes (upload-only, download-only, etc.)
- on-the-fly encryption
- command-line control

If you're open to doing this, I'd be happy to help test!

### Describe the solution you'd like

Support macOS. Similar functionality to what you have currently.

### Describe alternatives you've considered

I'm currently using Microsoft's first-party OneDrive software.

### Additional context

_No response_

The project is a Linux OneDrive client written in D. Start by reviewing the existing FreeBSD support in the codebase to understand the architecture. Look for platform-specific code and build configurations. Testing on macOS will be required to implement and verify the changes.

Written by the indexing model from the issue text.