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>

v4/tests/host_map.h

@@ -81,6 +81,7 @@
 #define MQ_HEAD      (BUF0_W - 35)              /* the messages waiting to be dealt with: where the oldest begins, */
 #define MQ_TAIL      (BUF0_W - 36)              /*   where the next will go, */
 #define MQ_COUNT     (BUF0_W - 37)              /*   and how many cells they take */
+#define AWAIT_FROM   (BUF0_W - 39)              /* the node whose word of how text ended is waited for */
 #define GATE_PORT    (BUF0_W - 38)              /* the port address a message is about to be begun on */
 #define NEAR         (BUF0_W - 64)              /* for each port, the number of the node on the other end; 0: not told */
 #define MQ_HDR       (BUF0_W - 56)              /* a message being taken in: its seven words and the port it came on */
@@ -194,6 +195,7 @@ static int host_load(v4_text *tx, v4_node *n, const char *const *files, unsigned
     v4_text_constant(tx, "-PORTS", -(v4_cell)V4_PORTS);
     v4_text_constant(tx, "(NEAR)", NEAR);
     v4_text_constant(tx, "(GATE-PORT)", GATE_PORT);
+    v4_text_constant(tx, "(AWAIT-FROM)", AWAIT_FROM);
     v4_text_constant(tx, "(MQ)", MQ_W);
     v4_text_constant(tx, "(MQ-END)", MQ_W + MQ_CELLS);
     v4_text_constant(tx, "-MQ-ROOM", -(v4_cell)(MQ_CELLS - 7));   /* cells taken + a text's words + this is below zero while the message fits */