fix(v4): the final review's six minors in the ROM boot

- Text after start is refused, as text.c refuses it: before it jumps, the
  ROM reads on to the end of the source; blanks, comments and the ends of
  blobs may follow, a token is ERR-AFTER (26), "text after start".
- A token too long where a name, a target or a value is wanted is "name
  too long", as text.c says: (MISSING) reports "missing" only when no error
  came first.  `", keeps "missing", which is text.c's word for both.
- text.c's "address out of range" names the address, not the value.
- The system's source files are one list, v4/sys_files.h: boot.c, the
  harness and the nucleus test are made from it.
- The ROM's error codes and words are one list, v4/rom_errors.h: boot.c's
  messages, host_map.h's ROM_ERR_* and mkmap's ERR-* are made from it.
- node.h says what v4_node_store does with a ROM address (nothing, as for
  any address outside RAM, D-14); test_host_rom_range pins it.

ROM: 2095 words, rom_hash 0x06d0dcb7a0cb41a1.  dict_hash unchanged,
0xe5a57f3eb72ff94a.  make -C v4 test test-32 hosted-check pass.  QEMU:
amd64, aarch64, riscv64 to ok>, POST 538/538, POST: PASSED.

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

v4/tests/rom_harness.h

@@ -12,6 +12,7 @@
 
 #include "v4/testcode.h"
 #include "host_map.h"
+#include "v4/sys_files.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -105,13 +106,15 @@ static void rom_boot(v4_node *n)
 }
 
 /* THE SYSTEM, AS THE MACHINE BUILDS IT (MACHINE.md section 6, step 1).  The
- * system's source, capsules/v4/sys (V4_SYS_DIR): the map, the fourteen and
+ * system's source, capsules/v4/sys (V4_SYS_DIR): the map, v4/sys_files.h and
  * the end, each followed by a new line and V4_ROM_BLOB_END, then EOT -- what v4/system/boot.c
  * feeds the console.  rom_system_text gives it whole, *len its length;
  * rom_build_system has `n`, booted with its ROM, assemble it, and runs it to
  * its start: 1 if it started, with *words the instruction words it took. */
-static const char *const rom_system_files[] = { "core", "input", "dict", "codegen", "compile", "quit", "forth",
-                                                "numout", "words", "system", "qmath", "blocks", "log", "acl" };
+#define ROM_SYS_FILE(file) #file,
+static const char *const rom_system_files[] = { V4_SYS_FILES(ROM_SYS_FILE) };
+#undef ROM_SYS_FILE
+#define ROM_SYS_FILES ((unsigned)(sizeof rom_system_files / sizeof rom_system_files[0]))
 
 static char *rom_system_text(size_t *len)
 {
@@ -119,12 +122,12 @@ static char *rom_system_text(size_t *len)
     char *text = malloc(cap);
     unsigned i;
     if (!text) return NULL;
-    for (i = 0; i < 16; i++) {
+    for (i = 0; i < ROM_SYS_FILES + 2u; i++) {
         char path[512];
         FILE *f;
         long n;
         if (i == 0) snprintf(path, sizeof path, "%s/map-%d.f18", V4_SYS_DIR, V4_CELL_BITS);
-        else if (i <= 14) snprintf(path, sizeof path, "%s/%s.f18", V4_SYS_DIR, rom_system_files[i - 1]);
+        else if (i <= ROM_SYS_FILES) snprintf(path, sizeof path, "%s/%s.f18", V4_SYS_DIR, rom_system_files[i - 1]);
         else snprintf(path, sizeof path, "%s/end.f18", V4_SYS_DIR);
         f = fopen(path, "rb");
         if (!f) { printf("    cannot read %s\n", path); free(text); return NULL; }