feat(v4.0.0): five nodes from nothing -- Hera asks for nodes, births and joins them

MESH.md step 5, in the fabric under test; the products are still one
node each until steps 8 and 9.

manage.c: what Hera asks of whoever holds the fabric, eleven requests by
KERNEL-WORD -- NODE-ME -BORN -WIRE -UNWIRE -SLEEP -WAKE -KILL -PARITY and
CAPSULE-OPEN -CELL -LINE. Nucleus: PORT!, SEND-ON, AWAIT, (SEAL).
capsules/v4/hera.4th: BIRTH and UNIT, the unit rule in FORTH and nowhere
else. The dictionary hash moves to the engine (v4_image_dict_hash).

test_host_unit.c, 34 checks, 64-bit: Hera is born empty, takes the
nucleus through her port, FORTH-79, POST and her capsule; 10 UNIT; four
nodes are born, each takes the nucleus and FORTH-79 through its port from
Hera and passes POST 538/538; four parities, one dictionary hash; they
talk, and a message between two corners not wired goes by Hera.

All v4 tests at both widths and under ASan+UBSan. hosted-check on three
ISAs. Bare metal: logs/20261006-143934 (amd64), -144204 (aarch64),
-144601 (riscv64).

Open, recorded in MESH.md: not run at 32 bits; a node that never answers
leaves Hera waiting; the capsules are read from files in the test, not
from the baked directory.

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

docs/v4.0.0/MESH.md

@@ -289,11 +289,11 @@ checked in this step.
 
 ## 9. Birth, and Hera
 
-**Proposal.** Hera asks, through the port where her requests go
-(`ENGINE.md` 3.3), for a node to be added and wired; she then sends the
-newborn its capsules through the port that joins them. Putting a node to
-sleep, waking it, and removing it are requests of the same kind. Only
-Hera's requests are honoured.
+**Proposal, built as step 5 (section 10).** Hera asks, through the port
+where her requests go (`ENGINE.md` 3.3), for a node to be added and wired;
+she then sends the newborn its capsules through the port that joins them.
+Putting a node to sleep, waking it, and removing it are requests of the
+same kind. Only Hera's requests are honoured.
 
 The unit rule (ruling 5) is Hera's, in capsule code: it is what she does
 with those requests. The engine and the host do not know it.
@@ -420,6 +420,62 @@ Each is tested, committed and pushed before the next.
    `FILL` now have fewer cases; nothing stops any other text doing what
    those cases did.
 5. **Birth and Hera's requests (section 9); the unit of five.**
+   **Done 2026-10-06, in the fabric under test; the products are still one
+   node each until steps 8 and 9.** Section 9's proposal, as built:
+   - *What Hera asks* (`v4/include/v4/manage.h`, `v4/src/manage.c`). Eleven
+     requests, each a word on her made with `KERNEL-WORD`, written to the
+     port her requests go to: `NODE-ME`, `NODE-BORN`, `NODE-WIRE`,
+     `NODE-UNWIRE`, `NODE-SLEEP`, `NODE-WAKE`, `NODE-KILL`, `NODE-PARITY`;
+     and `CAPSULE-OPEN`, `CAPSULE-CELL`, `CAPSULE-LINE`, by which she reads
+     a capsule the host has found and checked. A node is named to the host
+     by its place in the fabric; its number, which messages go by, is the
+     nodes' own. Only the node the host has wired to this is answered.
+   - *What a node needs to do it* (`v4/capsule/quit.v4`): `PORT! ( w port
+     -- )`, a cell written to a port as it is; `SEND-ON ( baddr u node port
+     -- )`, text by a port named, for a neighbour with no number yet;
+     `AWAIT ( node -- how )`, blocked until that node's word of how text
+     ended comes, keeping every other message for later; `(SEAL)`, what is
+     in the dictionary now is the system.
+   - *Hera's capsule* (`capsules/v4/hera.4th`, blocks 8000 to 8004), FORTH.
+     `BIRTH ( number port -- place )`: a node is asked for and wired to
+     that port; the nucleus is sent it cell by cell; it is told its number,
+     its console and that Hera is on its port 2; FORTH-79 and POST are sent
+     it a line at a time, each waited for; it seals; its parity is
+     recorded. `UNIT ( n -- )`: four births, on ports 2 to 5, and the four
+     joined in a square, each told of the two beside it. The unit rule is
+     there and nowhere else.
+   `v4/tests/test_host_unit.c`, 34 checks, 64-bit: Hera is born empty and
+   takes the nucleus through her port, then FORTH-79, POST (538 of 538) and
+   her capsule from the console; `10 UNIT`; four nodes are born, each
+   passes POST, the host records four parities with one dictionary hash;
+   all five wait and execute nothing; text for each outer node is done
+   there and what it prints comes back; `COLD` on one comes back to the
+   nucleus and FORTH-79; one outer node sends text to the one beside it,
+   and to the one across from it by way of Hera. Acceptance 1 and 2, in
+   the fabric. All v4 tests at both widths and under ASan and UBSan. The
+   single-node products are unchanged but for the nucleus's new words:
+   `hosted-check` on three ISAs; bare metal `logs/20261006-143934`
+   (amd64), `-144204` (aarch64), `-144601` (riscv64).
+   **What stands in, in the test only:** the capsules are read from the
+   files the build bakes in, and the nucleus capsule is written from the
+   nucleus as the test assembles it, not found in the baked directory with
+   its hash and signature checked; that is the host's part and comes with
+   step 8. Each node has a disk of its own attached at birth, as the boot's
+   one node has; storage through the ports is step 6.
+   **Not done, and open:**
+   - The test is not run on 32-bit cells: the POST capsule's expected
+     results are 64-bit v3's and the nucleus capsule is `nucleus-64`. POST
+     has never been run at 32 bits.
+   - A node that never answers leaves Hera waiting for ever in `AWAIT`;
+     she cannot then kill it. What she does about a birth that does not
+     finish is not decided.
+   - What an outer node prints while Hera is giving birth waits in Hera's
+     400 cells until she is idle, and is lost if there is more than they
+     hold. POST prints one line.
+   - An outer node has no port to the kernel, so no kernel words: no
+     `BYE`, and nothing it asks is honoured, as ruled.
+   - The suite now takes about four minutes, eight under the sanitizers:
+     five POSTs.
 6. **Storage (section 8).**
 7. **A second unit; scaling while running; sleep, wake and kill by
    command.**