FR: Tailnet rename or alias

### What are you trying to do?

I want to have a pretty name for my tailnet. My reason is fairly arbitrary: I have the iOS widget, and I don't like seeing "hakusaro.github" on my homescreen. I want it to say something cool like "socks".

### How should we solve this?

Can you add a feature to allow aliasing or renaming the tailnet? Even if renaming the tailnet isn't supported, it should be possible to have some kind of user-visible alias, right?

### What is the impact of not solving this?

I'm really sad.

### Anything else?

_No response_

No files, tests, or entry points are identified in the issue. Start by tracing how the iOS widget obtains and displays the tailnet name, then determine whether the requested alias should apply only there or across user-visible tailnet surfaces; done means an agreed scope and a working user-visible alias or rename.

Written by the indexing model from the issue text.