DTOB wire constants — keep in sync with vendor/dtob/lib/dtob.h and lexer.c.
The scanner in serve follows the same rules as lexer_next (blast skip, ctrl layout, custom range).
.dif entry scanning — tokenizer must stay aligned with vendor/dtob/src/lexer.c
(lexer_next): same ctrl layout, blast skip (DTOB_CODE_BLAST), and one TOK_DATA
blob per primitive payload. Chunked reads use NeedMore; the C lexer is not called here.