strandio: fail when http request gets cancelled

Instead of waiting for a proper response. Iris doesn't currently retry!

Also updates docket to detect this case and retry appropriately.

pkg/arvo/sys/vane/iris.hoon

@@ -332,6 +332,7 @@
     ::
     ::    TODO: We should gracefully retry on restart instead of just sending a
     ::    cancel.
+    ::    TODO  we might not want to do that though!
     ::
     =/  moves=(list move)
       %+  turn  ~(tap by connection-by-duct.state.ax)

pkg/base-dev/lib/strandio.hoon

@@ -386,6 +386,14 @@
   |=  tin=strand-input:strand
   ?+  in.tin  `[%skip ~]
       ~  `[%wait ~]
+    ::
+      [~ %sign [%request ~] %iris %http-response %cancel *]
+    ::NOTE  iris does not (yet?) retry after cancel, so it means failure
+    :-  ~
+    :+  %fail
+      %http-request-cancelled
+    ['http request was cancelled by the runtime']~
+    ::
       [~ %sign [%request ~] %iris %http-response %finished *]
     `[%done client-response.sign-arvo.u.in.tin]
   ==

pkg/garden/app/docket.hoon

@@ -292,7 +292,7 @@
         ?+    p.cage.sign  `state
             %thread-fail
           =+  !<([=term =tang] q.cage.sign)
-          ?.  =(term %cancelled)
+          ?.  |(=(term %cancelled) =(term %http-request-cancelled))
             =.  charges  (new-chad:cha hung+'glob-failed')
             :-  ~[add-fact:cha]
             ((slog leaf+"docket: thread failed;" leaf+<term> tang) state)