fix(v4.0.0): step 6e review round 2 -- only the message looked at is taken, moved or dropped; the kernel's port has no queue in a fabric; an answer nobody awaits is not a loss

- Engine: a wire keeps whether the message at its mark is the one last
  looked at; a node's take, move and drop of any other answer 3 and write
  nothing (MESH.md 7d.3).  A wire cut and made again between a look and a
  take no longer has a NACK done as text, or 256 cells written where one
  was looked for.
- Engine: v4_fabric_wire_kernel wires a kernel to a port with no queues;
  a message for it is refused at once, error 18, on a mesh as on the
  products.
- The result of a drop is looked at; a take that does not take has the
  message dropped, or gone past: nothing goes round.
- An answer nobody waits for is let go uncounted; (LOST) counts what should
  have been delivered or acted on and was not.  The flood's account is
  exact.
- Error 18 from under a word that was printing empties the data stack, as
  a fault does: that word's own values are not left there.
- Tests: the take and drop windows cut at every step, with and without
  another message put; a refusal owed to a stuck node whose wire is full.

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

docs/v4.0.0/MESH.md

@@ -800,6 +800,17 @@ the engine and happens whole.
 - Each wire has a mark for the node that reads it: the message that
   look, take, move and drop are about. First and next move it; with no
   message there, those four answer 3.
+- **Take, move and drop are done only on the message last looked at.**
+  A node looks, decides, and then takes; the wire may have been cut and
+  made again in between, and another message put where that one was. So
+  the wire keeps whether the message at its mark is the one last looked
+  at: a look that finds a message makes it so, and first, next, the
+  message's going, and the cutting of the wire undo it. Take, move and
+  drop of anything else answer 3 and change nothing, and a take writes
+  the cells of the message looked at and no more. *(Added 2026-10-08, fix
+  round 2 of tasks 2 and 3: a NACK was done as text, and a text of 1,024
+  characters taken where a NACK had been looked at overwrote the node's
+  variables.)*
 - Only 8 and 9 block. A node blocked there executes nothing.
 - **Sleep is woken by a message coming, not by one being there.** A node
   may leave a message for itself on a wire -- text it will not begin
@@ -877,9 +888,12 @@ waiting, the words that turned it, the list of NACKs owed, and
 ### 7d.5 The products
 
 The lone node on the hosted and bare-metal products is given the same
-addresses by its host (`v4/system/boot.c`): its two wires are the
-console and the kernel. Nothing else changes for it: the kernel's
-requests stay a word at a time.
+addresses by its host (`v4/system/boot.c`): its one wire is the
+console's. **The kernel's port has no queue** *(ruled 2026-10-08)*, on
+the products and in a fabric (`v4_fabric_wire_kernel`): the kernel is
+asked by words written to its port, as before, and takes no messages. A
+message for that port is refused at once -- error 18, "No one on that
+port".
 
 ### 7d.6 What will be limits