[TechNomadCode]

Slice 19: a Markdown table in the assistant's reply shows as a real table, the way opencode's desktop app shows one (markdown.css, Tables, at 50c5fce), instead of a labelled card per row.

• The header's named cells are column headers in medium weight over a stronger hairline; rows are apart by faint hairlines; no vertical lines; cells top-aligned with 12px padding. No pipe or Markdown mark shows as typed.
• <br> stays a line break inside its cell; an empty cell stays empty; a row with more cells than the header keeps them, and every row is padded so the hairlines run the full width.
• A table wider than the chat scrolls sideways inside the message, never the page. While it scrolls, its box is a named region in the tab order ("Table, scrolls sideways"), so the keyboard reaches it (axe's scrollable-region-focusable); a table that fits adds no tab stop.
• Unlike opencode's, each cell is at least 144px wide, so a wide table scrolls instead of squeezing its columns to a word per line (docs/decisions.md, Design).
• A second commit records the owner's choice for slice 20: opencode's "Thinking" row, then "Thought 7s" (docs/decisions.md, docs/plan.md).

For the measurement lane: this changes the parser in src/lib/markdown.ts, which only the browser uses; the model never sees its output. Nothing in src/server changes.

Tests: the parser's and the renderer's unit tests are rewritten for tables; two new end-to-end tests in tests/e2e/chat.spec.ts open a kept conversation holding a wide and a narrow table, at 1440px and 375px, with the accessibility check. Local: verify (468 unit tests) and test:e2e (66) passed.