fix: improve deno compatibility

[fvsch]

Deno requires permissions for a bunch of APIs.

One that feels a bit scary is --allow-env, while this package only looks at the env for color support metadata and other minor stuff.

This skips this kind of access in Deno, so that servitsy can run with:

deno run --allow-net --allow-read --allow-sys='uid,networkInterfaces' npm:servitsy

I need to investigate:

1. can the --allow-sys part can be reduced further?
2. can --allow-net be more precise?
3. would it be possible to do --allow-read=./some-folder and use that as the root folder?

[fvsch]

1. can the --allow-sys part can be reduced further?

Doesn't seem like it. The uid part is when checking user access to the root directory (or to any file we try to serve). The networkInterfaces part is when trying to determine the local network address.

2. can --allow-net be more precise?

Yes, but you’d need to combine with a specific --host and --port args, which is a bit hard.

3. would it be possible to do --allow-read=./some-folder and use that as the root folder?

First part is possible, but you can't use Deno.permissions to list allowed paths, you can only check if a specific path is allowed.