ames: improve scry interface

No longer abuse the desk field, instead making use of the path. Reject
any scries outside of the local ship, empty desk and current time as
invalid.

pkg/arvo/app/dbug.hoon

@@ -491,11 +491,11 @@
 ++  v-ames
   |%
   ++  peers
-    (scry (map ship ?(%alien %known)) %a %peers ~)
+    (scry (map ship ?(%alien %known)) %ax %$ /peers)
   ::
   ++  peer
     |=  who=ship
-    (scry ship-state:ames %a %peer /(scot %p who))
+    (scry ship-state:ames %ax %$ /peers/(scot %p who))
   ::
   ++  peer-to-json
     =,  ames

pkg/arvo/sys/vane/ames.hoon

@@ -691,35 +691,37 @@
   --
 ::  +scry: dereference namespace
 ::
-::    The ones producing vases are expected to be used like this:
-::
-::    &tang [(sell .^(vase %a /=peer=/~zod)) ~]
-::
 ++  scry
   |=  [fur=(unit (set monk)) ren=@tas why=shop syd=desk lot=coin tyl=path]
   ^-  (unit (unit cage))
-  ?.  =(lot [%$ %da now])  ~
-  ?.  =(%$ ren)  [~ ~]
-  ?.  =([%& our] why)
-    [~ ~]
-  ?+    syd  ~
-      %peers
-    ?^  tyl  [~ ~]
+  ::  only respond for the local identity, %$ desk, current timestamp
+  ::
+  ?.  ?&  =(&+our why)
+          =([%$ %da now] lot)
+          =(%$ syd)
+      ==
+    ~
+  ::  /ax/peers                    (map ship ?(%alien known))
+  ::  /ax/peers/[ship]             ship-state
+  ::  /ax/bones/[ship]             [snd=(set bone) rcv=(set bone)]
+  ::  /ax/snd-bones/[ship]/[bone]  vase
+  ::
+  ?.  ?=(%x ren)  ~
+  ?+    tyl  [~ ~]
+      [%peers ~]
     :^  ~  ~  %noun
     !>  ^-  (map ship ?(%alien %known))
     (~(run by peers.ames-state) head)
   ::
-      %peer
-    ?.  ?=([@ ~] tyl)  [~ ~]
-    =/  who  (slaw %p i.tyl)
+      [%peers @ ~]
+    =/  who  (slaw %p i.t.tyl)
     ?~  who  [~ ~]
     ?~  peer=(~(get by peers.ames-state) u.who)
       [~ ~]
     ``noun+!>(u.peer)
   ::
-      %bones
-    ?.  ?=([@ ~] tyl)  [~ ~]
-    =/  who  (slaw %p i.tyl)
+      [%bones @ ~]
+    =/  who  (slaw %p i.t.tyl)
     ?~  who  [~ ~]
     =/  per  (~(get by peers.ames-state) u.who)
     ?.  ?=([~ %known *] per)  [~ ~]
@@ -728,11 +730,10 @@
       [snd=~(key by snd) rcv=~(key by rcv)]
     ``noun+!>(res)
   ::
-      %snd-bone
-    ?.  ?=([@ @ ~] tyl)  [~ ~]
-    =/  who  (slaw %p i.tyl)
+      [%snd-bones @ @ ~]
+    =/  who  (slaw %p i.t.tyl)
     ?~  who  [~ ~]
-    =/  ost  (slaw %ud i.t.tyl)
+    =/  ost  (slaw %ud i.t.t.tyl)
     ?~  ost  [~ ~]
     =/  per  (~(get by peers.ames-state) u.who)
     ?.  ?=([~ %known *] per)  [~ ~]