add %peer-not "poison pill" peer

arvo/gall.hoon

@@ -242,6 +242,9 @@
       ::  to this returning pump.
       ::
       +>
+    ?:  ?=($peer-not -.q.caz)
+      ::  short circuit error
+      (mo-give %unto %reap (some p.q.caz))
     =^  num  +>.$  (mo-bale him)
     =+  ^=  roc  ^-  rook
         ?-  -.q.caz
@@ -532,6 +535,8 @@
       %+  mo-pass
         [%sys %val (scot %p q.q.pry) dap ~]
       [%f %exec our ~ (mo-beak dap) %cast p.cub %$ q.cub]
+    ?:  ?=($peer-not -.cub)
+      (mo-give %unto %reap (some p.cub))
     ap-abet:(ap-club:(ap-abed:ap dap pry) cub)
   ::
   ++  mo-club                                           ::  local action
@@ -713,6 +718,7 @@
         $peer   (ap-peer +.cub)
         $puff   !!
         $punk   !!
+        $peer-not   !!
         $pull   ap-pull
         $pump   ap-fall
       ==

arvo/zuse.hoon

@@ -2946,6 +2946,7 @@
       {$pull $~}                                        ::  unsubscribe
       {$punk p/mark q/cage}                             ::  translated poke
       {$pump $~}                                        ::  pump yes+no
+      {$peer-not p/tang}                                ::  poison pill peer
   ==                                                    ::
 ++  cuft                                                ::  internal gift
   $%  {$coup p/(unit tang)}                             ::  poke result