Import-list triage (done)

Cluster a module's unresolved imports by library and by first-touch order, so the output is a ranked work list rather than an alphabetical dump.

Done, and by a better route than the one imagined here: orbistoun-cli worklist ranks by observed call count across every run, not by first-touch order in a static dump. What a module might call and what it actually called turn out to be very different lists, and only the second one says where to spend an hour.