FreeBSD support (npm binary / pkg)

Hey! o/

Quick intro — I use Claude Code backed by DeepSeek and I've been eyeing DeepSeek-TUI for a bit. I'm on FreeBSD and I finally gave `npm install -g deepseek-tui` a shot today. Here's what I got:

```
root@worker:/home/user # npm install -g deepseek-tui
npm error deepseek-tui install failed: Unsupported platform: freebsd.
Supported platforms: 'linux', 'darwin', 'win32'.
npm error No prebuilt binary is available for this platform/architecture combo.
```

Fair enough — I knew it was a long shot :]

So here's my humble request: would you consider adding FreeBSD to the supported platforms? Two possible paths (not mutually exclusive, one can come way later than the other):

- **Ship a FreeBSD prebuilt binary on GitHub Releases** — The npm package already does the heavy lifting (downloads + installs binaries). It just needs a `freebsd` binary to pick up. This would unblock `npm install -g deepseek-tui` for us BSD folks right away.
- **`pkg install deepseek-tui`** — A proper FreeBSD port/package down the line. That's the long game, and I'm not expecting anyone to drop everything for it. But if it could land on the roadmap somewhere, that'd be amazing.

I know maintaining packages and build matrices isn't free. If you have no time for it right now, no worries — could you maybe plan it and add it to the roadmap? That way I know it's on the radar and I can keep an eye out. Totally fair if it's a "someday maybe" thing.

And hey, if you ever want someone to test the BSD side of things, I'm around and happy to help. Break my system, I don't mind :]

Cheers for the work you put into this — looking forward to trying it one way or another!