names.s gives each distinct identifier a 1-byte ID (1-255), comparing
case-insensitively across both PETSCII letter ranges. The table lives in
bank 1: 64 hash-chain heads plus 20-byte records holding the original
spelling. name_declare replaces the first-use spelling with the first
declaration's spelling, so forward references keep the declared form.
A full table returns NAMES_ERR_FULL and writes nothing.

Verified in x128: the C128 dump equals a host model byte for byte across
case variants, an 8-name collision chain with an identical-hash pair, and
a 260-name overflow, with a guard after the table intact. A mutation that
skips the text compare is caught. D120 (proposed): 255-name limit.

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