fix: the config decides where its results go

[sotashimozono]

Every driver did this:

const OUTDIR = get(ENV, "DATAVAULT_OUTDIR", joinpath(@__DIR__, "..", "out"))
vault = DataVault.Vault(CONFIG; run="phase1", outdir=OUTDIR)

Vault already resolves outdir itself:

resolved = if outdir !== nothing        # keyword
    string(outdir)
elseif haskey(ENV, "DATAVAULT_OUTDIR")  # environment
    ENV["DATAVAULT_OUTDIR"]
else
    spec.study.outdir                   # the config
end

A keyword wins, so passing one made the config's own [study] outdir permanently unreachable.
The comment above the line said "outdir precedence (DataVault resolves it): kwarg > ENV > config"
while the next line took the decision away from it. The documented order was "environment beats
config"; the real order was "the script beats everything".

Measured, both directions

DATAVAULT_OUTDIR unset    ->  out/data/example/phase1/       the config's [study] outdir
DATAVAULT_OUTDIR=/tmp/x   ->  /tmp/x/data/example/phase1/    the environment overriding it

The first of those could not happen before this change.

The drivers now pass run= only, and say why in a comment where the temptation is.

[github-actions]

📚 Docs preview: https://qatlashub.github.io/templateHPC.jl/previews/PR6/

(updates on each push to this PR)