gen: +desk-requests, counts pending clay requests

Gives a summation of pending clay requests for a given desk, specifying
the number of local and incoming-from-foreign requests, and for the
latter, how many of those are awaiting the next revision of a desk
(read: are currently |sync-ing from the desk).

pkg/arvo/gen/desk-requests.hoon

@@ -0,0 +1,28 @@
+::  +desk-requests: count pending requests for a desk
+::
+:-  %say
+|=  $:  [now=@da eny=@uvJ bec=beak]
+        [=desk ~]
+        ~
+    ==
+:-  %tang
+^-  tang
+=/  cul=(list [@p rave:clay])
+  %~  tap  in
+  .^  (set [@p rave:clay])
+    /cx/(scot %p p.bec)//(scot %da now)/cult/[desk]
+  ==
+::
+=/  [loc=_cul inc=_cul]
+  (skid cul |=([=@p rave:clay] =(p p.bec)))
+=/  syc=_cul
+  =/  nex=@ud
+    +(ud:.^(cass:clay %cw /(scot %p p.bec)/[desk]/(scot %da now)))
+  (skim inc |=([@p =rave:clay] =([%sing %w ud+nex /] rave)))
+::
+%-  flop
+:~  leaf+"total:     {<(lent cul)>}"
+    leaf+"- local:     {<(lent loc)>}"
+    leaf+"- incoming:  {<(lent inc)>}"
+    leaf+"  - for next:  {<(lent syc)>}"
+==