fix(v4): (DOWN) calls the GONE hook and puts (ONE) back; the hand-on swept

Found by the depth sweep: a hook that sent a message about another node
overwrote (ONE), which AWAIT reads after believing a GONE, so the wait went
on.  (DOWN) now calls the hook through (RUN) and restores (ONE).

AWAIT ended by a GONE that is handed on: works to 26 values and 21 calls
deep, then a stack error and nothing else, at both widths.  Removal sweep:
node 11 or 12 removed, or the wire cut, at every step: 0 wrong.  hosted
dict_hash=0x248b4edc47f4357e on all three ISAs.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

capsules/v4/sys/quit.f18

@@ -84,10 +84,20 @@ macro R-CLEAR   RSTACK-DEPTH b! a !b   endmacro
 \ there is one, is given the number of the node that is gone, in (ONE), so
 \ that the GONE goes on down the birth graph (MESH.md 9a.2, ruling 7;
 \ capsules/v4/centre.4th, GONE-DOWN).  0 there, as at switch-on: nothing.
-\ As (DEFINED) does (dict.f18): the xt goes on the return stack and ;
-\ goes there, so the word returns to whoever called this.
+\ The word is called, not jumped to, and (ONE) is put back when it
+\ returns: what called this -- AWAIT, with the node it waits on -- reads
+\ (ONE) after, and a GONE the word sends writes it.  (Found by the depth
+\ sweep of MESH.md 9a.6: a word that handed on a GONE about another node
+\ left AWAIT waiting for ever.)
+
+\ ( n xt -- )   the word whose xt it is, given n.  It returns to whoever
+\ called this, as (DEFINED) does (dict.f18).
+: (RUN)   push ;
+
 : (DOWN)
-  (GONE-HOOK) b! @b if NONE  (ONE) a! @  SWAP push ;
+  (GONE-HOOK) b! @b if NONE
+  drop  (ONE) a! @  dup push  (GONE-HOOK) b! @b  (RUN)
+  pop (ONE) a! ! ;
   NONE: drop ;
 
 \ ( -- flag )   A GONE has been taken: its seven words are in (IN), the