Model often emits | --- | --- | --- | rows as visual dividers between
table body rows. fixTables() now tracks whether the header separator has
been seen; any subsequent all-separator pipe row is dropped rather than
passed through to marked.js where it renders as a data row with --- content.

Existing fixes (missing separator injection, mixed row repair) are preserved.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>