feat: adapt to DSH 0.1.7-rc.1

Move the support line from 0.1.7-alpha.1 to 0.1.7-rc.1 (peer floor
`^0.1.7-rc.1`). 0.21.0-alpha.1 never reached npm, and once the code-card
labels below are fixed the same build crashes on alpha.1 (its DiffBlock
still reads the `labels.files` upstream deleted), so declaring only the
host we verify against is the honest floor — and from rc.1 on the host
enforces peers at boot anyway: a row whose `@deepseek-ai/dsh-*` peers do
not satisfy the runtime is silently disabled.

Dependencies: 28 devDependency pins and 14 peers move to 0.1.7-rc.1.
rc.1 also raised the vendored runtime (cordis 4.0.4, schemastery 3.18.4,
cordis-plugin-group 1.0.4, cordis-plugin-include 1.0.9) and publishes DSH
cross-references as exact versions, so bumping schemastery/cordis alone
left four unmet transitive peers — the three vendor packages are hoisted
into devDependencies, which is what makes `pnpm peers check` clean again.

One compile break: rc.1 added `CodeToolbarLabels` (codeLabel / wrapLabel /
unwrapLabel, all required), made DiffBlockLabels / ReadBlockLabels extend
it and deleted `DiffBlockLabels.files`. Fixing SideChatView then leaving
markdown on the legacy banner would render two different code-card styles
inside one side-chat view, so the plugin adopts the card everywhere:
`markdownTextProps()` now passes `labels.code.toolbarLabels` with the
host's own wording (codeBlock.title|wrap|unwrap, added to all 20
dictionaries; `sideChatBlockFiles` retires with the deleted footer).

Adopting the card surfaced a silent regression the suite caught: the new
toolbar shows `codeLabel` for languages the highlighter does not know, and
mermaid has no shiki grammar, so the info string no longer reaches the DOM
and the banner-text probe in mermaid.tsx matched nothing — mermaid fences
stopped being swapped for diagrams. Detection now matches the FENCE BODY
from the source that produced the render.

`tests/market-manifest.spec.ts` pins every DSH peer as a floating caret
range: an exact pin (the devDependency style) or a comparator without a
prerelease would fail rc.1's preflight and silently stop the plugin from
loading, and `pnpm peers check` cannot see that — it validates the
resolved dev tree, not the range shape the host reads.

src/client/MarkdownHtml.tsx

@@ -19,7 +19,7 @@ import { useLayoutEffect, useMemo, useRef } from 'react'
 import { createElement, type ReactNode } from 'react'
 import DOMPurify from 'dompurify'
 import { MarkdownText } from '@deepseek-ai/dsh-client-ui-primitives'
-import { markdownTextProps } from './markdown-labels.tsx'
+import { markdownTextProps, type MarkdownCopyLabels } from './markdown-labels.tsx'
 import { resolveLocalMediaDest, rewriteLocalImageUrls } from './markdown-images.ts'
 import {
   analyzeHtmlSegment,
@@ -160,7 +160,7 @@ interface MarkdownSegmentProps {
   text: string
   hasMermaid: boolean
   media: MarkdownHtmlMedia
-  codeLabels: { copyLabel: string; copiedLabel: string }
+  codeLabels: MarkdownCopyLabels
 }
 
 /**
@@ -218,7 +218,7 @@ type PreparedSegment =
 interface MarkdownDocumentProps {
   info: AnalyzedMarkdownHtml
   media: MarkdownHtmlMedia
-  codeLabels: { copyLabel: string; copiedLabel: string }
+  codeLabels: MarkdownCopyLabels
 }
 
 /**

src/client/SideChatView.tsx

@@ -121,6 +121,11 @@ interface ThreadCache {
 interface RowLabels {
   copyLabel: string
   copiedLabel: string
+  /** Code-card chrome (DSH 0.1.7-rc.1's fence toolbar): the markdown rows read
+   *  these three straight off this object, the diff / read cards mix them in. */
+  codeLabel: string
+  wrapLabel: string
+  unwrapLabel: string
   thinkLabel: string
   injectionLabel: string
   terminal: TerminalBlockLabels
@@ -345,9 +350,18 @@ export function SideChatView(props: {
       expand: (hidden: number) => t('sideChatBlockExpand', { hidden }),
       expandAria: (hidden: number) => t('sideChatBlockExpandAria', { hidden }),
     }
+    // DSH 0.1.7-rc.1 widened the diff / read cards into code cards and DELETED
+    // `DiffBlockLabels.files`, so the old "N files" footer is gone and these
+    // three strings are required by both cards.
+    const codeCard = {
+      codeLabel: t('codeBlockTitle'),
+      wrapLabel: t('codeBlockWrap'),
+      unwrapLabel: t('codeBlockUnwrap'),
+    }
     return {
       copyLabel: t('copy'),
       copiedLabel: t('copied'),
+      ...codeCard,
       thinkLabel: t('sideChatThink'),
       injectionLabel: t('sideChatInjection'),
       terminal: {
@@ -362,8 +376,8 @@ export function SideChatView(props: {
         done: t('sideChatBlockDone'),
         noOutput: t('sideChatBlockNoOutput'),
       },
-      diff: { ...shared, files: (count: number) => t('sideChatBlockFiles', { count }) },
-      read: { ...shared, window: (shown: number, total: number) => t('sideChatBlockWindow', { shown, total }) },
+      diff: { ...shared, ...codeCard },
+      read: { ...shared, ...codeCard, window: (shown: number, total: number) => t('sideChatBlockWindow', { shown, total }) },
     }
   }, [])
 

src/client/TextEditor.tsx

@@ -363,7 +363,13 @@ export function TextEditor(props: FileViewerProps) {
     // eslint-disable-next-line react-hooks/exhaustive-deps
     [scope.sessionId, scope.cwd, path],
   )
-  const codeLabels = { copyLabel: t('copy'), copiedLabel: t('copied') }
+  const codeLabels = {
+    copyLabel: t('copy'),
+    copiedLabel: t('copied'),
+    codeLabel: t('codeBlockTitle'),
+    wrapLabel: t('codeBlockWrap'),
+    unwrapLabel: t('codeBlockUnwrap'),
+  }
 
   /**
    * Selection popup for the markdown preview: a mouse-up inside the preview

src/client/changes/DiffPane.tsx

@@ -108,7 +108,13 @@ function PaneToggle(props: { on: boolean; label: string; title?: string; onClick
  *  lifted out); the plain path stays byte-for-byte for documents without
  *  any. */
 function MdReadingView(props: { text: string }) {
-  const codeLabels = { copyLabel: t('copy'), copiedLabel: t('copied') }
+  const codeLabels = {
+    copyLabel: t('copy'),
+    copiedLabel: t('copied'),
+    codeLabel: t('codeBlockTitle'),
+    wrapLabel: t('codeBlockWrap'),
+    unwrapLabel: t('codeBlockUnwrap'),
+  }
   const hasMermaid = splitMermaidBlocks(props.text).some((block) => block.kind === 'mermaid')
   return (
     <div className={css.paneBody}>

src/client/locales-ar.ts

@@ -361,7 +361,9 @@ export const ar: Record<string, string> = {
   sideChatBlockFailed: 'فشل',
   sideChatBlockDone: 'اكتمل',
   sideChatBlockNoOutput: '(لا يوجد إخراج)',
-  sideChatBlockFiles: '{count} ملفات',
+  codeBlockTitle: 'كتلة التعليمات البرمجية',
+  codeBlockWrap: 'التفاف الأسطر',
+  codeBlockUnwrap: 'بدون التفاف للأسطر',
   sideChatBlockWindow: '{shown} من {total} سطرًا',
   sideChatConnDisconnected: 'انقطع الاتصال',
   sideChatConnReconnect: 'إعادة الاتصال',

src/client/locales-de.ts

@@ -346,7 +346,9 @@ export const de: Record<string, string> = {
   sideChatBlockFailed: 'Fehlgeschlagen',
   sideChatBlockDone: 'Fertig',
   sideChatBlockNoOutput: '(keine Ausgabe)',
-  sideChatBlockFiles: '{count} Dateien',
+  codeBlockTitle: 'Codeblock',
+  codeBlockWrap: 'Zeilen umbrechen',
+  codeBlockUnwrap: 'Zeilen nicht umbrechen',
   sideChatBlockWindow: '{shown} von {total} Zeilen',
   sideChatConnDisconnected: 'Verbindung verloren',
   sideChatConnReconnect: 'Neu verbinden',

src/client/locales-fr.ts

@@ -353,7 +353,9 @@ export const fr: Record<string, string> = {
   sideChatBlockFailed: 'Échec',
   sideChatBlockDone: 'Terminé',
   sideChatBlockNoOutput: '(aucune sortie)',
-  sideChatBlockFiles: '{count} fichiers',
+  codeBlockTitle: 'Bloc de code',
+  codeBlockWrap: 'Retour à la ligne',
+  codeBlockUnwrap: 'Ne pas retourner à la ligne',
   sideChatBlockWindow: '{shown} sur {total} lignes',
   sideChatConnDisconnected: 'Connexion perdue',
   sideChatConnReconnect: 'Reconnecter',

src/client/locales-hi.ts

@@ -360,7 +360,9 @@ export const hi: Record<string, string> = {
   sideChatBlockFailed: 'विफल',
   sideChatBlockDone: 'पूर्ण',
   sideChatBlockNoOutput: '(कोई आउटपुट नहीं)',
-  sideChatBlockFiles: '{count} फ़ाइलें',
+  codeBlockTitle: 'कोड ब्लॉक',
+  codeBlockWrap: 'पंक्तियाँ लपेटें',
+  codeBlockUnwrap: 'पंक्तियाँ न लपेटें',
   sideChatBlockWindow: 'कुल {total} में से {shown} पंक्तियाँ',
   sideChatConnDisconnected: 'कनेक्शन टूट गया',
   sideChatConnReconnect: 'फिर से कनेक्ट करें',

src/client/locales-id.ts

@@ -358,7 +358,9 @@ export const id: Record<string, string> = {
   sideChatBlockFailed: 'Gagal',
   sideChatBlockDone: 'Selesai',
   sideChatBlockNoOutput: '(tanpa output)',
-  sideChatBlockFiles: '{count} file',
+  codeBlockTitle: 'Blok kode',
+  codeBlockWrap: 'Bungkus baris',
+  codeBlockUnwrap: 'Jangan bungkus baris',
   sideChatBlockWindow: '{shown} dari {total} baris',
   sideChatConnDisconnected: 'Koneksi terputus',
   sideChatConnReconnect: 'Sambungkan ulang',

src/client/locales-it.ts

@@ -351,7 +351,9 @@ export const it: Record<string, string> = {
   sideChatBlockFailed: 'Non riuscito',
   sideChatBlockDone: 'Completato',
   sideChatBlockNoOutput: '(nessun output)',
-  sideChatBlockFiles: '{count} file',
+  codeBlockTitle: 'Blocco di codice',
+  codeBlockWrap: 'A capo automatico',
+  codeBlockUnwrap: 'Nessun a capo',
   sideChatBlockWindow: '{shown} di {total} righe',
   sideChatConnDisconnected: 'Connessione persa',
   sideChatConnReconnect: 'Riconnetti',

src/client/locales-ja.ts

@@ -360,7 +360,9 @@ export const ja: Record<string, string> = {
   sideChatBlockFailed: '失敗',
   sideChatBlockDone: '完了',
   sideChatBlockNoOutput: '（出力なし）',
-  sideChatBlockFiles: '{count} 個のファイル',
+  codeBlockTitle: 'コードブロック',
+  codeBlockWrap: '折り返しを有効にする',
+  codeBlockUnwrap: '折り返しを無効にする',
   sideChatBlockWindow: '全 {total} 行中 {shown} 行を表示',
   sideChatConnDisconnected: '接続が切断されました。クリックで再接続',
   sideChatConnReconnect: '再接続',

src/client/locales-ko.ts

@@ -352,7 +352,9 @@ export const ko: Record<string, string> = {
   sideChatBlockFailed: '실패',
   sideChatBlockDone: '완료',
   sideChatBlockNoOutput: '(출력 없음)',
-  sideChatBlockFiles: '파일 {count}개',
+  codeBlockTitle: '코드 블록',
+  codeBlockWrap: '줄 바꿈',
+  codeBlockUnwrap: '줄 바꿈 해제',
   sideChatBlockWindow: '전체 {total}줄 중 {shown}줄 표시',
   sideChatConnDisconnected: '연결이 끊겼습니다',
   sideChatConnReconnect: '다시 연결',

src/client/locales-nl.ts

@@ -358,7 +358,9 @@ export const nl: Record<string, string> = {
   sideChatBlockFailed: 'Mislukt',
   sideChatBlockDone: 'Voltooid',
   sideChatBlockNoOutput: '(geen uitvoer)',
-  sideChatBlockFiles: '{count} bestanden',
+  codeBlockTitle: 'Codeblok',
+  codeBlockWrap: 'Regels afbreken',
+  codeBlockUnwrap: 'Regels niet afbreken',
   sideChatBlockWindow: '{shown} van {total} regels',
   sideChatConnDisconnected: 'Verbinding verbroken',
   sideChatConnReconnect: 'Opnieuw verbinden',

src/client/locales-pl.ts

@@ -362,7 +362,9 @@ export const pl: Record<string, string> = {
   sideChatBlockFailed: 'Niepowodzenie',
   sideChatBlockDone: 'Zakończono',
   sideChatBlockNoOutput: '(brak wyniku)',
-  sideChatBlockFiles: 'Pliki: {count}',
+  codeBlockTitle: 'Blok kodu',
+  codeBlockWrap: 'Zawijanie wierszy',
+  codeBlockUnwrap: 'Bez zawijania wierszy',
   sideChatBlockWindow: '{shown} z {total} wierszy',
   sideChatConnDisconnected: 'Połączenie utracone',
   sideChatConnReconnect: 'Połącz ponownie',

src/client/locales-pt.ts

@@ -343,7 +343,9 @@ export const pt: Record<string, string> = {
   sideChatBlockFailed: 'Falhou',
   sideChatBlockDone: 'Concluído',
   sideChatBlockNoOutput: '(sem saída)',
-  sideChatBlockFiles: '{count} arquivos',
+  codeBlockTitle: 'Bloco de código',
+  codeBlockWrap: 'Quebrar linhas',
+  codeBlockUnwrap: 'Não quebrar linhas',
   sideChatBlockWindow: '{shown} de {total} linhas',
   sideChatConnDisconnected: 'Conexão perdida',
   sideChatConnReconnect: 'Reconectar',

src/client/locales-ru.ts

@@ -358,7 +358,9 @@ export const ru: Record<string, string> = {
   sideChatBlockFailed: 'Ошибка',
   sideChatBlockDone: 'Готово',
   sideChatBlockNoOutput: '(нет вывода)',
-  sideChatBlockFiles: 'Файлов: {count}',
+  codeBlockTitle: 'Блок кода',
+  codeBlockWrap: 'Переносить строки',
+  codeBlockUnwrap: 'Не переносить строки',
   sideChatBlockWindow: '{shown} из {total} строк',
   sideChatConnDisconnected: 'Соединение потеряно',
   sideChatConnReconnect: 'Переподключиться',

src/client/locales-sv.ts

@@ -343,7 +343,9 @@ export const sv: Record<string, string> = {
   sideChatBlockFailed: 'Misslyckades',
   sideChatBlockDone: 'Klar',
   sideChatBlockNoOutput: '(ingen utdata)',
-  sideChatBlockFiles: '{count} filer',
+  codeBlockTitle: 'Kodblock',
+  codeBlockWrap: 'Radbrytning',
+  codeBlockUnwrap: 'Ingen radbrytning',
   sideChatBlockWindow: '{shown} av {total} rader',
   sideChatConnDisconnected: 'Anslutningen bröts',
   sideChatConnReconnect: 'Anslut igen',

src/client/locales-th.ts

@@ -360,7 +360,9 @@ export const th: Record<string, string> = {
   sideChatBlockFailed: 'ล้มเหลว',
   sideChatBlockDone: 'เสร็จสิ้น',
   sideChatBlockNoOutput: '(ไม่มีเอาต์พุต)',
-  sideChatBlockFiles: '{count} ไฟล์',
+  codeBlockTitle: 'บล็อกโค้ด',
+  codeBlockWrap: 'ตัดบรรทัดอัตโนมัติ',
+  codeBlockUnwrap: 'ไม่ตัดบรรทัด',
   sideChatBlockWindow: '{shown} จาก {total} บรรทัด',
   sideChatConnDisconnected: 'การเชื่อมต่อขาดหาย',
   sideChatConnReconnect: 'เชื่อมต่อใหม่',

src/client/locales-tr.ts

@@ -360,7 +360,9 @@ export const tr: Record<string, string> = {
   sideChatBlockFailed: 'Başarısız',
   sideChatBlockDone: 'Tamamlandı',
   sideChatBlockNoOutput: '(çıktı yok)',
-  sideChatBlockFiles: '{count} dosya',
+  codeBlockTitle: 'Kod bloğu',
+  codeBlockWrap: 'Satırları kaydır',
+  codeBlockUnwrap: 'Satırları kaydırma',
   sideChatBlockWindow: '{total} satırdan {shown} satır',
   sideChatConnDisconnected: 'Bağlantı koptu',
   sideChatConnReconnect: 'Yeniden bağlan',

src/client/locales-vi.ts

@@ -360,7 +360,9 @@ export const vi: Record<string, string> = {
   sideChatBlockFailed: 'Thất bại',
   sideChatBlockDone: 'Hoàn tất',
   sideChatBlockNoOutput: '(không có đầu ra)',
-  sideChatBlockFiles: '{count} tệp',
+  codeBlockTitle: 'Khối mã',
+  codeBlockWrap: 'Ngắt dòng',
+  codeBlockUnwrap: 'Không ngắt dòng',
   sideChatBlockWindow: '{shown} trong {total} dòng',
   sideChatConnDisconnected: 'Mất kết nối',
   sideChatConnReconnect: 'Kết nối lại',

src/client/locales-zh-HK.ts

@@ -375,7 +375,9 @@ export const zhHK: Record<string, string> = {
   sideChatBlockFailed: '失敗',
   sideChatBlockDone: '完成',
   sideChatBlockNoOutput: '（無輸出）',
-  sideChatBlockFiles: '{count} 個檔案',
+  codeBlockTitle: '程式碼區塊',
+  codeBlockWrap: '自動換行',
+  codeBlockUnwrap: '取消自動換行',
   sideChatBlockWindow: '共 {total} 行 · 顯示 {shown} 行',
   sideChatConnDisconnected: '連線已中斷',
   sideChatConnReconnect: '重新連線',

src/client/locales-zh-MO.ts

@@ -375,7 +375,9 @@ export const zhMO: Record<string, string> = {
   sideChatBlockFailed: '失敗',
   sideChatBlockDone: '完成',
   sideChatBlockNoOutput: '（無輸出）',
-  sideChatBlockFiles: '{count} 個檔案',
+  codeBlockTitle: '程式碼區塊',
+  codeBlockWrap: '自動換行',
+  codeBlockUnwrap: '取消自動換行',
   sideChatBlockWindow: '共 {total} 行 · 顯示 {shown} 行',
   sideChatConnDisconnected: '連線已中斷',
   sideChatConnReconnect: '重新連線',

src/client/locales-zh-TW.ts

@@ -375,7 +375,9 @@ export const zhTW: Record<string, string> = {
   sideChatBlockFailed: '失敗',
   sideChatBlockDone: '完成',
   sideChatBlockNoOutput: '（無輸出）',
-  sideChatBlockFiles: '{count} 個檔案',
+  codeBlockTitle: '程式碼區塊',
+  codeBlockWrap: '自動換行',
+  codeBlockUnwrap: '取消自動換行',
   sideChatBlockWindow: '共 {total} 行 · 顯示 {shown} 行',
   sideChatConnDisconnected: '連線已中斷',
   sideChatConnReconnect: '重新連線',

src/client/locales.ts

@@ -372,7 +372,9 @@ export const zh = {
   sideChatBlockFailed: '失败',
   sideChatBlockDone: '完成',
   sideChatBlockNoOutput: '（无输出）',
-  sideChatBlockFiles: '{count} 个文件',
+  codeBlockTitle: '代码块',
+  codeBlockWrap: '自动换行',
+  codeBlockUnwrap: '取消自动换行',
   sideChatBlockWindow: '共 {total} 行 · 显示 {shown} 行',
   sideChatConnDisconnected: '连接已断开，点击立即重连',
   sideChatConnReconnect: '重新连接',
@@ -805,7 +807,9 @@ export const en: Record<keyof typeof zh, string> = {
   sideChatBlockFailed: 'Failed',
   sideChatBlockDone: 'Done',
   sideChatBlockNoOutput: '(no output)',
-  sideChatBlockFiles: '{count} files',
+  codeBlockTitle: 'Code block',
+  codeBlockWrap: 'Wrap lines',
+  codeBlockUnwrap: 'Do not wrap lines',
   sideChatBlockWindow: '{shown} of {total} lines',
   sideChatConnDisconnected: 'Disconnected, reconnect now',
   sideChatConnReconnect: 'Reconnect',

src/client/markdown-labels.tsx

@@ -1,5 +1,5 @@
 /**
- * Copy-button / chrome labels for DSH's shared `MarkdownText` (DSH
+ * Chrome labels for DSH's shared `MarkdownText` (DSH
  * 0.1.2-alpha contract): the renderer takes a REQUIRED nested `labels` prop
  * — `labels.code.copyLabel` / `labels.code.copiedLabel` for the fence copy
  * buttons plus a screen-reader-only `labels.footnotes` heading — and the
@@ -8,15 +8,29 @@
  * dictionary's localized pair through here (re-evaluated per render).
  * `footnotes` is left empty (the heading is sr-only; give it a real string
  * only if a locale key ever earns its place in all 19 dictionaries).
+ *
+ * DSH 0.1.7-rc.1 added `labels.code.toolbarLabels` (language name + wrap
+ * toggle + copy). Supplying it is what swaps the legacy info-string banner for
+ * the host's code card, and the three strings are REQUIRED once supplied, so
+ * every site that builds the flat pair has to carry them too — the code card
+ * must look the same in the transcript, the diff card and the editor preview as
+ * it does in DSH's own chat.
  */
 import type { ComponentProps } from 'react'
 import { MarkdownText } from '@deepseek-ai/dsh-client-ui-primitives'
 
-/** The flat copy-button pair the plugin threads through its own props (e.g.
- *  MermaidMarkdownProps.codeLabels — the chunk contract stays put). */
+/** The code-card chrome the plugin threads through its own props (e.g.
+ *  MermaidMarkdownProps.codeLabels — the chunk contract carries the same
+ *  fields). */
 export interface MarkdownCopyLabels {
   copyLabel: string
   copiedLabel: string
+  /** Code-card title for an absent or unsupported language. */
+  codeLabel: string
+  /** Code-card action that enables wrapping. */
+  wrapLabel: string
+  /** Code-card action that preserves source columns with horizontal scrolling. */
+  unwrapLabel: string
 }
 
 /** MarkdownText props carrying the nested chrome labels. */
@@ -24,7 +38,15 @@ export function markdownTextProps(text: string, labels: MarkdownCopyLabels): Com
   return {
     text,
     labels: {
-      code: { copyLabel: labels.copyLabel, copiedLabel: labels.copiedLabel },
+      code: {
+        copyLabel: labels.copyLabel,
+        copiedLabel: labels.copiedLabel,
+        toolbarLabels: {
+          codeLabel: labels.codeLabel,
+          wrapLabel: labels.wrapLabel,
+          unwrapLabel: labels.unwrapLabel,
+        },
+      },
       footnotes: '',
     },
   }

src/client/mermaid-blocks.ts

@@ -9,6 +9,8 @@
  * tests/mermaid-blocks.spec.ts).
  */
 
+import type { MarkdownCopyLabels } from './markdown-labels.tsx'
+
 /** One fenced mermaid diagram lifted out of the markdown source. */
 export interface MermaidBlock {
   kind: 'mermaid'
@@ -28,7 +30,7 @@ export type MdBlock = MarkdownBlock | MermaidBlock
 export interface MermaidMarkdownProps {
   /** The full markdown source (rendered in a single MarkdownText pass). */
   text: string
-  codeLabels: { copyLabel: string; copiedLabel: string }
+  codeLabels: MarkdownCopyLabels
 }
 
 /** CommonMark opening fence: 0-3 spaces indent + a run of 3+ backticks or tildes. */

src/client/mermaid.tsx

@@ -34,6 +34,7 @@ import { markdownTextProps } from './markdown-labels.tsx'
 import { t } from './locales.ts'
 import { sanitizeSvg } from './mermaid-sanitize.ts'
 import type { MermaidMarkdownProps } from './mermaid-blocks.ts'
+import { splitMermaidBlocks } from './mermaid-blocks.ts'
 import css from './sidebar.module.css'
 
 /** Monotonic id seed: every render call gets a fresh, document-unique id. */
@@ -315,20 +316,45 @@ interface MermaidMount {
 }
 
 /**
- * True when a rendered CodeBlock is a mermaid fence. The DSH CodeBlock has
- * two bodies: the shiki path carries the `language-*` class on generated
- * <code> elements, while the plain path (which is always the one mermaid
- * takes — no shiki grammar) only shows the language in the banner
- * infostring (first element of the banner row; CSS-module classes are
- * hashed, so that match is structural).
+ * Fence bodies of every mermaid fence in the source, normalized for matching
+ * against the rendered block.
+ * @param text - the markdown source the same component renders.
+ * @returns the trailing-whitespace-normalized diagram sources.
  */
-function isMermaidBlock(block: HTMLElement): boolean {
+function mermaidFenceBodies(text: string): Set<string> {
+  const bodies = new Set<string>()
+  for (const block of splitMermaidBlocks(text)) {
+    if (block.kind === 'mermaid') bodies.add(block.code.trimEnd())
+  }
+  return bodies
+}
+
+/** The block's fence body as rendered: CodeBlock trims one trailing newline. */
+function blockBody(block: HTMLElement): string {
+  return (block.querySelector('code')?.textContent ?? '').trimEnd()
+}
+
+/**
+ * True when a rendered CodeBlock is a mermaid fence.
+ *
+ * The match is by FENCE BODY, not by the header: DSH ≤ 0.1.7-alpha.1 rendered a
+ * banner whose info string said `mermaid`, but rc.1's code card shows
+ * `labels.codeLabel` for any language the highlighter does not know, and
+ * mermaid has no shiki grammar — so once the card is adopted the language word
+ * is nowhere in the DOM. The body is, in both card variants, and the component
+ * already has the source that produced it.
+ *
+ * The `language-mermaid` class stays as the first probe: the highlighted arm
+ * would carry it if a grammar ever appears for the fence.
+ * @param block - one rendered `.md-code-block`.
+ * @param bodies - {@link mermaidFenceBodies} of the source being rendered.
+ * @returns whether this block holds a mermaid diagram.
+ */
+function isMermaidBlock(block: HTMLElement, bodies: ReadonlySet<string>): boolean {
   const code = block.querySelector('code')
-  if (code !== null && [...code.classList].some(c => c.startsWith('language-mermaid'))) return true
-  const infostring = block.firstElementChild?.firstElementChild?.firstElementChild
-  return infostring !== null
-    && infostring !== undefined
-    && (infostring.textContent ?? '').trim() === 'mermaid'
+  if (code === null) return false
+  if ([...code.classList].some(c => c.startsWith('language-mermaid'))) return true
+  return bodies.has(blockBody(block))
 }
 
 /**
@@ -350,10 +376,11 @@ export function MermaidMarkdown({ text, codeLabels }: MermaidMarkdownProps): Rea
     if (container === null) return
     const mounts = mountsRef.current
     const seen = new Set<HTMLElement>()
+    const bodies = mermaidFenceBodies(text)
 
     for (const block of container.querySelectorAll<HTMLElement>('.md-code-block')) {
       const mount = mounts.get(block)
-      const isMermaid = isMermaidBlock(block)
+      const isMermaid = isMermaidBlock(block, bodies)
       if (!isMermaid) {
         // A previously swapped block that is no longer a mermaid fence:
         // restore the CodeBlock children React still manages, so the plain

src/client/service.ts

@@ -633,7 +633,7 @@ export function matchUrlTarget(tabs: readonly TabDescriptor[], url: URL): TabDes
  * The plugin version this service instance reports. Keep in lockstep with
  * `package.json`'s version — `tests/service.spec.ts` asserts the pair.
  */
-export const SIDEBAR_SERVICE_VERSION = '0.21.0-alpha.1'
+export const SIDEBAR_SERVICE_VERSION = '0.21.0-rc.1'
 
 /**
  * Monotonic capability list consumers use to gate new API usage (features