Replace the hardcoded isToolMarkupPipe (matching |, |, ␂, \x02, !) and
isToolCDATAOpenSeparator (exclusion-based) with a single isToolMarkupSeparator
that treats any Unicode punctuation outside structural characters as a valid
DSML separator. This eliminates the need for a per-character allowlist — novel
separators like ※ are automatically supported without code changes. Also
removes the unused cdataPattern regexp and updates docs to use "non-structural
separator" terminology.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>