docs(v4.0.0): messaging -- a v4 node is handed text and sends by asking

Records kernel-Hermes as built and the ruling of 2026-10-05; the open
question of a node's safe moment; and the stated intent to pull Artemis up
into the kernel later, as Hermes was.

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

docs/v4.0.0/V3-PARITY.md

@@ -187,6 +187,42 @@ ACL, migration and the Stadium touch stay where they are.
 array behind its four block registers (D-19), which skips the address
 space, the metadata, the owner, the ACL and the Stadium.
 
+## 1e. Messaging (discussed and ruled 2026-10-05)
+
+**v3, as built** (`FABRIC-3.5.md` sections III, XLIII, XLV;
+`kernel/include/starkernel/vm/kernel_hermes.h`):
+
+- Hermes is the kernel, not a VM: the routing layer between the Stadium
+  floor and the HAL.
+- A message is a patron. Its heat is the Stadium cell it occupies; sending
+  draws a slot's worth from the sender's reservoir; a ledger of held,
+  pulled, returned and consumed is audited for conservation.
+- Publish and subscribe: one permanent common channel every VM joins at
+  birth; a private channel by request and grant or deny, with ACK/NACK.
+- Who may open a channel with whom is ACL policy: kernel-Hermes asks
+  `ACL.4th` and does not decide.
+- A payload is FORTH text, one block at most; larger is chunked.
+- Hermes delivers into no one. It queues the payload for the target and
+  publishes the fact. The target drains its own queue at its outermost
+  interpret checkpoint by interpreting the text; the switcher reads the
+  same fact to choose which VM runs.
+
+**Ruling (Captain Bob, "yes"):** a v4 node receives by being handed text
+to interpret, and sends by asking. Everything else stays in kernel-Hermes:
+heat, channels, the ACL question, queues, the ledger, the switcher.
+
+**Open.** v3's safe moment is a per-word checkpoint in the inner loop, at
+the outermost interpret level. A v4 node has no inner loop. What a node's
+safe moment is has to be defined; it is also where the switcher moves
+control, so it decides how the fleet shares the processor.
+
+**Intent stated, for later (Captain Bob, 2026-10-05):** "When Artemis time
+comes, we're going to pull that up into the kernel as well." As Hermes
+became kernel-Hermes. Not this step. Today Artemis the VM is
+`capsules/artemis/init.4th`: 550 lines, 77 words — a flat-pool disk manager
+(header, free map, allocator, format and resume, Stadium admission for
+allocated blocks, K total, cooling, reap, self-tests).
+
 ## 2. Row 3: physics and per-word heat
 
 ### 2.1 What v3 does