fix: update the mockup metadata for the run page

The metadata didn't include the nodes as standalone sections, and the
multiplicity was not found, since it was moved from each instance up to
the node.
fix: correct run JIT overview
change: default port for UI dev is now 8082

So that now the SlipStreamServer in dev mode runs at 8080 and the UI at
8082 and they can run both in parallel.

NB: In my personal setting the legacy UI (i.e. the one that is still in
prod) runs at 8081, so that I can have all three running in parallel.