Merge remote-tracking branch 'origin/master' into mergebot/pr908

# Conflicts:
#	packages/client/ui-conversation/README.i18n.yaml
#	packages/client/ui-trajectory/src/client/views.module.css

packages/client/ui-primitives/src/markdown/plain-text.ts

@@ -0,0 +1,124 @@
+/**
+ * Markdown-to-plain-text projection for compact summaries and labels.
+ * Parsing shares the renderer's GFM grammar; raw HTML stays literal, links
+ * keep their labels, images keep alt text, and code keeps its source text.
+ */
+
+import { fromMarkdown } from 'mdast-util-from-markdown'
+import { gfmFromMarkdown } from 'mdast-util-gfm'
+import { gfm } from 'micromark-extension-gfm'
+
+/** Amount of parsed Markdown content returned by the extractor. */
+export type MarkdownPlainTextMode = 'all' | 'first-line' | 'first-paragraph'
+
+/** Options for {@link extractMarkdownPlainText}. */
+export interface MarkdownPlainTextOptions {
+  /** Projection boundary; defaults to the complete document. */
+  mode?: MarkdownPlainTextMode
+}
+
+interface MarkdownNode {
+  type: string
+  value?: string
+  alt?: string
+  children?: MarkdownNode[]
+}
+
+function inlineText(node: MarkdownNode): string {
+  switch (node.type) {
+    case 'text':
+    case 'inlineCode':
+    case 'code':
+      return node.value ?? ''
+    case 'image':
+    case 'imageReference':
+      return node.alt ?? ''
+    case 'break':
+      return '\n'
+    case 'html':
+      return node.value ?? ''
+    default:
+      return node.children?.map(inlineText).join('') ?? ''
+  }
+}
+
+function compactInline(text: string): string {
+  return text.replace(/\s+/g, ' ').trim()
+}
+
+function blockText(node: MarkdownNode): string {
+  switch (node.type) {
+    case 'root':
+    case 'blockquote':
+      return node.children?.map(blockText).filter(Boolean).join('\n\n') ?? ''
+    case 'paragraph':
+    case 'heading':
+      return compactInline(inlineText(node))
+    case 'code':
+      return node.value?.trim() ?? ''
+    case 'list':
+      return node.children?.map(blockText).filter(Boolean).join('\n') ?? ''
+    case 'listItem':
+      return node.children?.map(blockText).filter(Boolean).join(' ') ?? ''
+    case 'table':
+      return node.children?.map(blockText).filter(Boolean).join('\n') ?? ''
+    case 'tableRow':
+      return node.children?.map(blockText).join('\t') ?? ''
+    case 'tableCell':
+      return compactInline(inlineText(node))
+    case 'html':
+      return node.value ?? ''
+    case 'thematicBreak':
+    case 'definition':
+      return ''
+    default:
+      return compactInline(inlineText(node))
+  }
+}
+
+function findFirstParagraph(node: MarkdownNode): string | undefined {
+  if (node.type === 'paragraph') {
+    const text = compactInline(inlineText(node))
+    if (text !== '') return text
+  }
+  for (const child of node.children ?? []) {
+    const text = findFirstParagraph(child)
+    if (text !== undefined) return text
+  }
+  return undefined
+}
+
+function fullText(root: MarkdownNode): string {
+  return blockText(root)
+    .split('\n')
+    .map(line => line.trim())
+    .join('\n')
+    .replace(/\n{3,}/g, '\n\n')
+    .trim()
+}
+
+/**
+ * Parse GFM Markdown, remove its presentation markup, and preserve raw HTML literally.
+ * @param markdown - Markdown source.
+ * @param options - Optional extraction boundary.
+ * @returns Plain text for the whole document, first visible line, or first semantic paragraph.
+ */
+export function extractMarkdownPlainText(
+  markdown: string,
+  options: MarkdownPlainTextOptions = {},
+): string {
+  const { mode = 'all' } = options
+  const root = fromMarkdown(markdown, {
+    extensions: [gfm()],
+    mdastExtensions: [gfmFromMarkdown()],
+  }) as MarkdownNode
+  const all = fullText(root)
+  switch (mode) {
+    case 'all':
+      return all
+    case 'first-line':
+      return all.split('\n').find(line => line !== '') ?? ''
+    case 'first-paragraph':
+      return findFirstParagraph(root) ?? all.split('\n').find(line => line !== '') ?? ''
+  }
+}