feat(v4): word accounts at call -- the word ID in the header, the kernel's records, the Stadium charged per tick (#189)

ENGINE step 4 Phase 2 (plan docs/v4.0.0/plans/2026-11-13-engine-step4-phase2-word-accounts.md). Rulings,
Captain Bob 2026-11-13: "ID field in the header"; "Per heartbeat tick"; the ACL "All of it in Phase 4".

- The word ID, at xt-4 before the flags (ENGINE.md 3b). The system's words are numbered as they are
  assembled, by a new directive, #id, (and #ids, the count), in the C assembler (text.c) and in the
  machine ROM's (capsules/v4/rom), which counts in the system's own (NEXT-ID). (HEADER) numbers later
  words; FORGET gives back the IDs it frees, always the newest; COLD resets to (BOOT-ID); (SEAL) records
  it. All 313 system headers carry the cell.
- The kernel's records (v4/mesh.h): (TELL-DEFINED) and (TELL-FORGOTTEN), requests -19/-20 on port 0,
  which the kernel puts in (WORD-DEFINED)/(WORD-FORGOTTEN) when it seals a node, and reads the system's
  own words once. A bit per address marks a word's xt (calls into the ROM or headerless code are not
  words); at call, the bit test and a count. v4_mesh_charge hands the owner the calls since.
- The Stadium: stadium_words_charge -- N calls as N of stadium_word_dispatch's dispatches, shared by calls
  when the reservoir is short; sk_v4.c charges every node's words at the tick beside its opcodes, and
  stadium_word_forget before an ID is used again.
- Tests first: test_text.c, test_host_dict.c, test_host_quit.c (numbering, FORGET, COLD),
  test_mesh_boot.c (44 checks), kernel/tests/test_stadium_words.c; qemu_session.py: Hera's words
  admitted after POST.
- amd64: Stadium words: promotions=141 after POST, CONSERVED; POST 539/539; word_count=377;
  dict_hash 0xa854ba15b437d288 (the new cell); the boot 142 s against Phase 1's 153 s.
- v4 test, test-32: all pass; v4-checks: 80 programs under the sanitizers, 0 failures; the hosted
  builds alike. docs/reference/v4-dictionary.tsv: the two new words; FABRIC-3 XLVIII.24.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017RzZgrf7V7Zk2iczBXDRbm

v4/tests/host_map.h

@@ -212,6 +212,8 @@ enum { V4_ROM_ERRORS(ROM_ERR_ENUM_) ROM_ERR_END_ };
 #define WORD_FORGOTTEN (BUF0_W - 12)             /* the xt of the word that is told when entries go, or 0 */
 #define LOG_LEVEL    (BUF0_W - 5)               /* the level at or below which a message is printed */
 #define BOOT_CELLS   (BVARS + 14)               /* (BOOT): DP and LATEST as the loader left them, 2 cells */
+#define NEXT_ID      (BVARS + 10)               /* (NEXT-ID): the word ID the next entry is given (#189, Phase 2) */
+#define BOOT_ID      (BVARS + 11)               /* (BOOT-ID): (NEXT-ID) as the loader left it, which COLD comes back to */
 #define BUF0_W       (BVARS - (v4_cell)(V4_BLOCK_SLOTS * V4_BLOCK_CELLS))   /* the block window: the kernel's slots, 256 cells each (v4/blocks.h) */
 /* The ports and the addresses after them, through V4_PORT_HAVE (node.h, MESH.md 7d.3), are not memory and must be where
  * no variable is: after the output buffer, which ends at BUF0_W - 144, and before OUT_HDR, the first variable above it.
@@ -285,6 +287,8 @@ static unsigned host_branch_slots(void)
     X("(W)", WVARS) \
     X("(X)", XVARS) \
     X("(BOOT)", BOOT_CELLS) \
+    X("(NEXT-ID)", NEXT_ID) \
+    X("(BOOT-ID)", BOOT_ID) \
     X("(LOG-LEVEL)", LOG_LEVEL) \
     X("(ACL-HOOK)", ACL_HOOK) \
     X("SCR", SCR) \
@@ -430,6 +434,9 @@ static int host_load(v4_text *tx, v4_node *n, const char *const *files, unsigned
     n->mem[VOC_LINK] = 0;
     /* and the text interpreted is the terminal's */
     n->mem[SRC] = TIB;
+    /* the word IDs the source's headers took (#id,), as end.f18 stores them on the machine (#189, Phase 2) */
+    n->mem[NEXT_ID] = tx->next_id;
+    n->mem[BOOT_ID] = tx->next_id;
     return 1;
 }