Minification and concatenation of CSS and Javascript (with Plack?)

[Pierre M]

> does the exemple in the docs, or t/basic.t in the distribution not point
you in the right direction?  Is there something missing from the docs that
is causing you pain?
Haha! I'm remembering now what I thought last week: my files are not all in
the same folder, so I have to list them all first. I had tried <**/*.css>
and the wildcard didn't work; I left that in the code last week, and this
week assumed it did work. Sorry for a question whose answer I had.

Plack::App::MCCS <https://metacpan.org/pod/Plack::App::MCCS> seems good.
How to you use it with a Dancer2 app? (what is $app in the case of a
Dancer2 app?)