Stage S-1b: dictionary word ids grow with the dictionary; a word that can't get an id is refused whole (FABRIC-3.9.0 §8.1)

- word_id_map / recycled_word_ids are heap tables (one shared capacity,
  64 doubling), grown all-or-nothing by allocate-copy-free. Numbering is
  unchanged, so boot parity is unchanged.
- vm_create_word() takes the id before linking; on failure it frees the
  entry, sets vm->error, logs LOG_ERROR and counts
  (vm_dictionary_word_id_refusals()). No word runs with WORD_ID_INVALID.
- Readers of the id space bound by vm->next_word_id, not DICTIONARY_SIZE.
- transition_heat gets its own capacity and grows on record (was sized
  once -- a heap overflow under a dynamic bound); every reader bounds by it.
- Stadium id->cell rows start empty and grow on dispatch; a failed grow is
  logged, counted and not admitted. S-2 (the cell pool) stays open.

Probe (reverted), identical on amd64/aarch64/riscv64: +2000 words get real
ids (capacity 4096); a word at id 2738 lands 200x in the rolling window and
is Stadium-admitted; FORGET recycles across the old boundary; an injected
grow failure refuses the word whole (NULL, error, counter, dictionary
unchanged) and the retry succeeds. 3-ISA acceptance passes; boot parity
(531, 0x572daac83b797332) and the dict_hash set unchanged.

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

src/word_source/physics_pipelining_diagnostic_words.c

@@ -206,7 +206,7 @@ static void forth_PIPELINING_SHOW_TOP_TRANSITIONS(VM *vm) {
     memset(top, 0, sizeof(TransitionPair) * top_count);
 
     /* Scan all words and keep top N */
-    for (uint32_t i = 0; i < DICTIONARY_SIZE; i++) {
+    for (uint32_t i = 0; i < m->transition_heat_cap; i++) {
         uint64_t count = m->transition_heat[i];
         if (count == 0) continue;
 
@@ -373,9 +373,10 @@ static void forth_PIPELINING_ANALYZE_WORD(VM *vm) {
     printf("=" "=" "=" "=" "=" "=" "=" "=" "=" "=" "=" "=" "=" "=" "=" "=" "=" "=" "=" "=" "\n");
 
     /* Calculate entropy / distribution spread */
-    double avg_count = (double)m->total_transitions / DICTIONARY_SIZE;
+    /* S-1b: the id space is vm->next_word_id, no longer a fixed DICTIONARY_SIZE. */
+    double avg_count = (double)m->total_transitions / (vm->next_word_id ? vm->next_word_id : 1u);
     double max_count = 0;
-    for (uint32_t i = 0; i < DICTIONARY_SIZE; i++) {
+    for (uint32_t i = 0; i < m->transition_heat_cap; i++) {
         if (m->transition_heat && m->transition_heat[i] > max_count) {
             max_count = (double)m->transition_heat[i];
         }