The native <code filetype=markdown> colorizes pipes but never aligns tables.
Add a pure segmenter (segmentMarkdown) that splits assistant text into prose
runs (native renderable) and GFM table blocks, plus an MdTable grid renderer:
per-column widths (free-code's stringWidth+padAligned), :--- / :--: / ---:
alignment, bold header, dim │ separators, a ┼ header rule, width-aware column
shrink on resize. Incomplete tables (no separator yet, e.g. mid-stream) stay
prose until they close. +5 unit tests (85 pass); verified live with a 3-col table.
c6e72a8454