hark-graph-hook: cast the interior of the vase for speed
update-core
=* pos p.post.node
=+ !< notif-kind=(unit notif-kind:hook)
- (get-conversion !>([0 pos]))
+ %- get-conversion
+ !>(`indexed-post:graph-store`[0 pos])
?~ notif-kind
update-core
=/ desc=@t
