graph-store: add dm validator

pkg/arvo/app/dm-hook.hoon

@@ -49,12 +49,12 @@
         %add-nodes
       ?>  ?=([@ %inbox] resource.q.update)
       ?:  =(our.bowl src.bowl)
-        (incoming-add nodes.q.update)
         (outgoing-add nodes.q.update)
+      (incoming-add nodes.q.update)
     ==
   ==
   ::
-  ++  incoming-add
+  ++  outgoing-add
     |=  nodes=(map index:store node:store)
     ^-  (list card)
     %-  zing
@@ -73,7 +73,7 @@
     :+  %add-nodes  [our.bowl %inbox]
     (~(gas by *(map index:store node:store)) [index node] ~)
   ::
-  ++  outgoing-add
+  ++  incoming-add
     |=  nodes=(map index:store node:store)
     ^-  (list card)
     ?>  =(1 ~(wyt by nodes))

pkg/arvo/mar/graph/validator/dm.hoon

@@ -0,0 +1,23 @@
+/-  *post, met=metadata-store, graph=graph-store, hark=hark-graph-hook
+|_  i=indexed-post
+++  grow
+  |%
+  ++  noun  i
+  ++  notification-kind
+    ^-  (unit notif-kind:hark)
+    ?+  index.p.i  ~
+      [@ ~]  `[%message [0 1] %count %none]
+    ==
+  ::
+  --
+++  grab
+  |%
+  ++  noun
+    |=  p=*
+    =/  ip  ;;(indexed-post p)
+    ?>  ?=(?([@ ~] [@ @ ~]) index.p.ip)
+    ip
+  --
+::
+++  grad  %noun
+--