- src/core/math-delims.ts: pure preprocessing for the \(...\)/\[...\] math
contract — balanced delimiters rewrite to the two-dollar forms remark-math
parses ($ is never math). Skips code fences/spans, escaped delimiters, and
leaves unbalanced (mid-stream) delimiters untouched. Display math renders
as a block: mid-paragraph gets blank-line padding; indented (list items)
degrades to inline so list continuations don't half-parse.
- message.tsx: transform in the render path (children-memoized); math plugin
now singleDollarTextMath: false — the currency hazard dies structurally.
remark-breaks via the cjk remarkPluginsAfter slot (the bare remarkPlugins
prop would replace the [remark-gfm, codeMeta] defaults).
- mermaid: dark theme + sans font via Streamdown's mermaid prop; dark-styled
error fallback (components/mermaid-error.tsx) with error, source in
<details>, and retry.
- globals.css (appended): @source for streamdown dist — its internal UI
chrome (code blocks, mermaid containers, tables) was entirely unstyled
because Tailwind v4 never scans node_modules; --color-sidebar → card; wide
mermaid SVGs capped to the column; .katex-display scrolls.
- tests/render-markdown.test.tsx: 26 tests (transform unit + render). The
math describe block in render-cards.test.tsx is updated to the new
contract ($...$ now renders as literal text — pinned).
