fix: fallback to COMP_LINE for project parsing

[thde]

Fixes shell completion not finding resources when using --project flag and updateds kong-completion to v0.0.11.

When completing positional arguments in nested subcommands, the posener/complete library slices args.All as it descends through subcommands, making the --project flag unavailable to the predictor.

I also added tests using complete.New() to verify the actual completion behavior.

Manual Test

COMP_LINE="nctl exec --project ninetest application " go run .

[thirdeyenick]

Thanks! Looking good. Just a question: is the COMP_LINE env variable a shell specific thing or is this the same for any shell?

[thde]

Thanks! Looking good. Just a question: is the COMP_LINE env variable a shell specific thing or is this the same for any shell?

It's a package specific one. So it works the same for all shells.

[thirdeyenick]

Thanks! Looking good. Just a question: is the COMP_LINE env variable a shell specific thing or is this the same for any shell?

It's a package specific one. So it works the same for all shells.

Thx!

[thde]

Well that wasn't really correct. It's standard for Bash, but the library configures it as well for fish and uses bash completion for zsh.