Through the path an application actually takes — nsswitch, files, then DNS —
because the resolv.conf module is half of what is being tested and only that
path goes through it. Asking a server directly would prove less.
Both machines resolve, from their own copy: a mesh where one machine answers
for all of them stops resolving when that machine does, which is the
arrangement this design refuses everywhere else.
The manifests are read from mesh-control's examples rather than written here,
so what is proven is what ships. And dnsmasq joins the base image, read back
through --version like the others: a machine that cannot answer names applies
the resolver data, reports success, and resolves nothing.