Stage S-1c: WORD's buffer is per VM; input buffers allotted at VM init, below all compiled code (FABRIC-3.9.0 §8.1)

- The static word_scratch_addr shared by every VM is gone: WORD builds in
  vm->word_buf (257 bytes: count + 255 + NUL). A token over 255 chars is
  refused whole (delimiter restored, >IN unconsumed, vm->error), logged at
  LOG_ERROR and counted -- no more silent cut to 62 chars.
- Pre-existing corruption found by the probe: TIB/>IN/SPAN (and WORD's
  scratch) were allotted lazily at HERE; POST's restore_dict_state(),
  FORGET and COLD rolled HERE below them and compiled the dictionary over
  them (Hera's TIB lay under ACL-RECHECK's body; QUERY/WORD wrote into
  code). Per Captain Bob, all four are now allotted first in both
  vm_init()s (offsets 0-1305); COLD's clamp never goes below them.

Probe (reverted), identical on amd64/aarch64/riscv64: 0 colon bodies inside
the buffers; per-VM isolation; 62/100/255-char tokens full length; 300
refused and counted; interpreter sane after full-width TIB writes.
3-ISA acceptance passes; M7.1a hash and dict_hash set unchanged (here
0xd8 -> 0x5f8).

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

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