ui : wrap markdown tables in a scroll container

Markdown tables render as a bare <table>, which keeps its content-driven minimum width and can stretch the chat column past the window. The table-wrapper CSS already existed, but nothing produced the wrapper.

Add a rehype plugin that wraps each table in div.table-wrapper, following the existing enhance-* plugins.

Assisted-by: pi:deepseek-ai/DeepSeek-V4.1-Flash

tools/ui/src/lib/components/app/content/MarkdownContent/markdown-processor.ts

@@ -11,6 +11,7 @@ import { rehypeEnhanceCodeBlocks } from './plugins/rehype/enhance-code-blocks';
 import { rehypeEnhanceLinks } from './plugins/rehype/enhance-links';
 import { rehypeEnhanceMermaidBlocks } from './plugins/rehype/enhance-mermaid-blocks';
 import { rehypeEnhanceSvgBlocks } from './plugins/rehype/enhance-svg-blocks';
+import { rehypeEnhanceTables } from './plugins/rehype/enhance-tables';
 import { rehypeFileBadge } from './plugins/rehype/file-badge';
 import { rehypeMermaidPre } from './plugins/rehype/mermaid-pre';
 import { rehypeRtlSupport } from './plugins/rehype/rehype-rtl-support';
@@ -73,6 +74,7 @@ function buildPipeline({
 			languages: lowlightAll
 		}) // Add syntax highlighting
 		.use(rehypeRestoreTableHtml) // Restore limited HTML (e.g. <br>, <ul>) inside Markdown tables
+		.use(rehypeEnhanceTables) // Wrap tables in a horizontal scroll container
 		.use(rehypeEnhanceLinks) // Add target="_blank" to links
 		.use(rehypeFileBadge) // Render file:// anchors as inline badge chips
 		.use(rehypeMermaidPre) // Convert mermaid blocks to <pre class="mermaid">

tools/ui/src/lib/components/app/content/MarkdownContent/plugins/rehype/enhance-tables.ts

@@ -0,0 +1,34 @@
+/**
+ * Rehype plugin to wrap tables in a horizontal scroll container.
+ *
+ * A bare <table> keeps its content-driven minimum width, which propagates up
+ * the layout and can stretch the chat column past the window. Wrapping in
+ * div.table-wrapper makes the wrapper the scroll container (styled in
+ * markdown-content.css), so wide tables scroll in place instead.
+ */
+
+import type { Element, ElementContent, Root } from 'hast';
+import type { Plugin } from 'unified';
+import { visit } from 'unist-util-visit';
+
+export const rehypeEnhanceTables: Plugin<[], Root> = () => {
+	return (tree: Root) => {
+		visit(tree, 'element', (node: Element, index, parent) => {
+			if (node.tagName !== 'table' || !parent || index === undefined) return;
+
+			// already wrapped (e.g. nested tables in raw HTML input)
+			const parentClass = parent.type === 'element' ? parent.properties?.className : undefined;
+
+			if (Array.isArray(parentClass) && parentClass.includes('table-wrapper')) return;
+
+			const wrapper: Element = {
+				children: [node as ElementContent],
+				properties: { className: ['table-wrapper'] },
+				tagName: 'div',
+				type: 'element'
+			};
+
+			parent.children[index] = wrapper;
+		});
+	};
+};