Can't add dependencies to a specific invocation of a recipe with arguments

I'm playing with just for the first time and decided to experiment by rewriting this simple Makefile I'm currently using:

```Makefile
default: ign/cluster-1.ign

ign/cluster-1.ign: ign/system.ign ign/ssh.ign ign/k8s.ign
ign/%.ign: %.butane | igndir
butane -s $< -d $(@D) > $@

.PHONY: igndir
igndir:
mkdir -p ign
```

This generates ignition files from butane files. It also encapsulates the dependency that the cluster-1 ignition imports the system, ssh, and k8s ignitions, so they must be built first. This was my Justfile attempt:

```
default: (ign cluster-1)

ign cluster-1: (ign system) (ign ssh) (ign k8s)
ign IGN: igndir
butane -s "{{IGN}}.butane" -d . > "ign/{{IGN}}.ign"

@igndir:
mkdir -p ign
```

Unfortunately this dies with:

```
error: Recipe `ign` first defined on line 3 is redefined on line 4
|
4 | ign IGN: igndir
| ^^^
```

This is idiomatic and very powerful in make, and consequently I use it extensively. I couldn't see an obvious way to do this in just. I don't want a new recipe; I want to declare that when this recipe is called for 'cluster-1' specifically it has some additional dependencies.

Is there some other more idiomatic way of doing this in just?

The issue names no files or tests. Start by tracing how just parses recipe definitions and handles dependencies for parameterized invocations, then look for related parser or dependency tests. Done means the requested invocation-specific dependency behavior is supported with coverage, or the limitation and idiomatic alternative are clearly documented.

Written by the indexing model from the issue text.