diff --git a/packages/client/ui-primitives/README.i18n.yaml b/packages/client/ui-primitives/README.i18n.yaml
index 74c0cf2516..d6c7014509 100644
--- a/packages/client/ui-primitives/README.i18n.yaml
+++ b/packages/client/ui-primitives/README.i18n.yaml
@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/client/ui-primitives/README.md
-README.md: 29d7b5e20dbc3a53fe4b85e219b0c957c05ed873
-README.zh.md: 92d256f7f1d413a9792aa54f50317c2a15dd09a0
+README.md: 99d5f8b238ce78d83de0b5247d194b308dd6fac0
+README.zh.md: 468aa75e88580d6ed5e78666ad34c18b22a85dd3
diff --git a/packages/client/ui-primitives/README.md b/packages/client/ui-primitives/README.md
index 29d7b5e20d..99d5f8b238 100644
--- a/packages/client/ui-primitives/README.md
+++ b/packages/client/ui-primitives/README.md
@@ -6,7 +6,7 @@ Pure React atoms (zero cordis): StateDot, ic_ds_* icons, Button/Pill/Menu/Modal/
 
 ## Markdown rendering
 
-`MarkdownText` renders GFM from untrusted assistant output through React elements. It omits raw HTML, neutralizes relative and non-HTTP(S)/mailto links, opens HTTP(S) links with safe external-link attributes, and renders image alt text without loading remote resources; `MessageText` remains the literal-text primitive for user-authored content. Element spacing, tables, links, and inline code use the same `--dsw-alias-markdown-*` / `--dsw-font-markdown-*` tokens as deepsuite `@deepseek/md`. Fenced blocks render through `CodeBlock` (language banner, copy control, shiki for the registered grammars).
+`MarkdownText` renders GFM from untrusted assistant output through React elements. It omits raw HTML, neutralizes relative and non-HTTP(S)/mailto links, opens HTTP(S) links with safe external-link attributes, and renders image alt text without loading remote resources; `MessageText` remains the literal-text primitive for user-authored content. `extractMarkdownPlainText` removes Markdown presentation markup for compact labels while preserving raw HTML as literal text. Element spacing, tables, links, and inline code use the same `--dsw-alias-markdown-*` / `--dsw-font-markdown-*` tokens as deepsuite `@deepseek/md`. Fenced blocks render through `CodeBlock` (language banner, copy control, shiki for the registered grammars).
 
 ## Model Experience
 
diff --git a/packages/client/ui-primitives/README.zh.md b/packages/client/ui-primitives/README.zh.md
index 92d256f7f1..468aa75e88 100644
--- a/packages/client/ui-primitives/README.zh.md
+++ b/packages/client/ui-primitives/README.zh.md
@@ -6,7 +6,7 @@
 
 ## Markdown 渲染
 
-`MarkdownText` 通过 React 元素渲染来自不受信任 assistant 输出的 GFM。它会省略原始 HTML，使相对链接及非 HTTP(S)/mailto 链接失效，以安全的外部链接属性打开 HTTP(S) 链接，并只渲染图片 alt 文本而不加载远程资源；`MessageText` 仍是用户创作内容使用的字面文本原语。元素间距、表格、链接与行内代码使用与 deepsuite `@deepseek/md` 相同的 `--dsw-alias-markdown-*` / `--dsw-font-markdown-*` token。围栏代码块通过 `CodeBlock` 渲染（语言横幅、复制控件，以及对已注册语法使用 shiki）。
+`MarkdownText` 通过 React 元素渲染来自不受信任 assistant 输出的 GFM。它会省略原始 HTML，使相对链接及非 HTTP(S)/mailto 链接失效，以安全的外部链接属性打开 HTTP(S) 链接，并只渲染图片 alt 文本而不加载远程资源；`MessageText` 仍是用户创作内容使用的字面文本原语。`extractMarkdownPlainText` 会移除 Markdown 呈现标记以用于紧凑标签，同时将原始 HTML 保留为字面文本。元素间距、表格、链接与行内代码使用与 deepsuite `@deepseek/md` 相同的 `--dsw-alias-markdown-*` / `--dsw-font-markdown-*` token。围栏代码块通过 `CodeBlock` 渲染（语言横幅、复制控件，以及对已注册语法使用 shiki）。
 
 ## 模型体验
 
diff --git a/packages/client/ui-primitives/src/markdown/plain-text.ts b/packages/client/ui-primitives/src/markdown/plain-text.ts
index a3e20c1179..af449dc774 100644
--- a/packages/client/ui-primitives/src/markdown/plain-text.ts
+++ b/packages/client/ui-primitives/src/markdown/plain-text.ts
@@ -1,6 +1,6 @@
 /**
  * Markdown-to-plain-text projection for compact summaries and labels.
- * Parsing shares the renderer's GFM grammar; raw HTML is omitted, links
+ * 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.
  */
 
@@ -36,7 +36,7 @@ function inlineText(node: MarkdownNode): string {
     case 'break':
       return '\n'
     case 'html':
-      return ''
+      return node.value ?? ''
     default:
       return node.children?.map(inlineText).join('') ?? ''
   }
@@ -67,7 +67,7 @@ function blockText(node: MarkdownNode): string {
     case 'tableCell':
       return compactInline(inlineText(node))
     case 'html':
-      return ''
+      return node.value ?? ''
     case 'thematicBreak':
     case 'definition':
       return ''
@@ -98,7 +98,7 @@ function fullText(root: MarkdownNode): string {
 }
 
 /**
- * Parse GFM Markdown and project its user-visible plain text.
+ * 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.
diff --git a/packages/client/ui-primitives/tests/markdown-plain-text.spec.ts b/packages/client/ui-primitives/tests/markdown-plain-text.spec.ts
index 481d78bd8a..010d5803ab 100644
--- a/packages/client/ui-primitives/tests/markdown-plain-text.spec.ts
+++ b/packages/client/ui-primitives/tests/markdown-plain-text.spec.ts
@@ -34,10 +34,18 @@ describe('extractMarkdownPlainText', () => {
       .toBe('First paragraph with a link and diagram.')
   })
 
-  it('omits raw HTML and returns a useful fallback when no paragraph exists', () => {
-    const markdown = '<script>alert(1)</script>\n\n## Safe heading'
-    expect(extractMarkdownPlainText(markdown)).toBe('Safe heading')
-    expect(extractMarkdownPlainText(markdown, { mode: 'first-paragraph' })).toBe('Safe heading')
+  it('preserves raw HTML while removing Markdown presentation markup', () => {
+    const block = [
+      '<background-task-complete id="trajectory-ui-watch">',
+      'Command: pnpm test',
+      'Exit code: 0',
+      '</background-task-complete>',
+    ].join('\n')
+    expect(extractMarkdownPlainText(block)).toBe(block)
+    expect(extractMarkdownPlainText('**Status:** <span data-state="ok">ready</span>'))
+      .toBe('Status: <span data-state="ok">ready</span>')
+    expect(extractMarkdownPlainText(block, { mode: 'first-paragraph' }))
+      .toBe('<background-task-complete id="trajectory-ui-watch">')
   })
 
   it('projects GFM tables, references, hard breaks, and block structure', () => {
@@ -54,7 +62,7 @@ describe('extractMarkdownPlainText', () => {
       '[asset]: diagram.png',
     ].join('\n')
     expect(extractMarkdownPlainText(markdown)).toBe([
-      'first second with diagram and visible',
+      'first second with diagram and <span>visible</span>',
       '',
       'Name\tValue',
       'alpha\t1',
diff --git a/packages/client/ui-trajectory/tests/table.spec.tsx b/packages/client/ui-trajectory/tests/table.spec.tsx
index ee073c754e..7c0b567311 100644
--- a/packages/client/ui-trajectory/tests/table.spec.tsx
+++ b/packages/client/ui-trajectory/tests/table.spec.tsx
@@ -83,6 +83,34 @@ describe('TrajectoryTable', () => {
     expect(screen.getByText('15 tok')).toBeTruthy()
   })
 
+  it('keeps raw HTML tags in a Markdown-derived context preview', () => {
+    const html = [
+      '<background-task-complete id="trajectory-ui-watch">',
+      'Command: pnpm test',
+      'Exit code: 0',
+      '</background-task-complete>',
+    ].join('\n')
+    const turns: readonly TrajectoryTurnModel[] = [{
+      turn: 1,
+      groups: [{
+        title: 'Message',
+        cells: [{
+          index: 1,
+          kind: 'context',
+          text: '',
+          inputDetail: html,
+          timeSeconds: 0,
+        }],
+      }],
+    }]
+
+    render(<TrajectoryTable turns={turns} {...FOLD_PROPS} />)
+
+    expect(screen.getByText(
+      '<background-task-complete id="trajectory-ui-watch"> Command: pnpm test Exit code: 0 </background-task-complete>',
+    )).toBeTruthy()
+  })
+
   it('keeps running and failure semantics distinct from record roles', () => {
     const view = render(<TrajectoryTable turns={TURNS} {...FOLD_PROPS} />)
     expect(view.container.querySelector('tr[data-kind="tool"][data-running="true"]')).toBeTruthy()