fix(web-cards): restore AT status text, guard file-link keys, add read docs

Address review of the ToolRow card refactor:
- ToolRow renders a visually-hidden run-state label (row.running/failed/stopped
  locale keys) so a running/failed/interrupted row is not a colour-only signal;
  the StateDot and the sweep are both aria-hidden. Restores the stopped-state
  text assertion in diff-card.spec at the ToolRow layer.
- The file-link button stops Enter/Space from bubbling to DisclosureRow's
  whole-row keydown, which would preventDefault the key and toggle expand
  instead of opening the file (the keyboard analogue of the click stopPropagation).
- search-row passes output={model.output} unconditionally, matching the other
  three card rows (ToolRow renders the card over the output when present).
- Assert locale: 'conversation' in the search/web/diff registration tests.
- Add the read render-intent paragraph to the ui-conversation README and a
  ReadBlock atom entry + Read section to ui-primitives (both languages).
- Update the grep fixture sample lines to the post-refactor SearchRow shape.
Refresh the code-mode-round, steering, and search-card goldens for the added
status text and updated sample lines.

packages/client/ui-conversation/src/client/chat/ToolRow.module.css

@@ -289,3 +289,15 @@
   --dsl-terminal-output-max-height: 224px;
   border: 1px solid var(--dsw-alias-border-l1);
 }
+
+/* Visually hidden run-state label for assistive technology: the StateDot and
+   the running sweep are aria-hidden / colour-only, so the text carries the
+   running/failed/interrupted state to a screen reader. */
+.visuallyHidden {
+  position: absolute;
+  width: 1px;
+  height: 1px;
+  overflow: hidden;
+  clip: rect(0 0 0 0);
+  white-space: nowrap;
+}

packages/client/ui-conversation/src/client/chat/ToolRow.tsx

@@ -19,7 +19,7 @@
 // independent); an error row's collapsed summary is the failure's first line in
 // the error color.
 
-import { useState, type MouseEvent, type ReactNode } from 'react'
+import { useState, type KeyboardEvent, type MouseEvent, type ReactNode } from 'react'
 import clsx from 'clsx'
 import {
   CodeBlock, DiffBlock, ReadBlock, SearchBlock, StateDot, TerminalBlock, WebBlock,
@@ -118,6 +118,19 @@ function leadingFor(state: ToolRowState, icon: ReactNode): ReactNode {
   }
 }
 
+/** Visually hidden run-state label: the StateDot and the CSS sweep are both
+ *  aria-hidden / colour-only, so assistive technology needs this text to know a
+ *  row is running, failed, or interrupted. null in the ok state (the icon and
+ *  summary already describe a settled row). */
+function stateStatus(state: ToolRowState, t: TranslateNS<'conversation'>): string | null {
+  switch (state) {
+    case 'running': return t('row.running')
+    case 'error': return t('row.failed')
+    case 'stopped': return t('row.stopped')
+    default: return null
+  }
+}
+
 export function ToolRow({
   t,
   variant,
@@ -151,6 +164,9 @@ export function ToolRow({
   const card = terminalBody ?? diffBody ?? readBody ?? searchBody ?? webBody
   const expandable = body !== null || outputText !== null || card !== null
   const open = expanded && expandable
+  // The run-state label AT needs: the StateDot and the running sweep are both
+  // aria-hidden / colour-only, so a stopped or running row is otherwise silent.
+  const status = stateStatus(state, t)
   // An error row's collapsed summary IS the failure: the first error line in
   // the error color outranks both the args summary and a terminal description.
   const failureLine = state === 'error' ? errorSummary ?? null : null
@@ -164,6 +180,13 @@ export function ToolRow({
     event.stopPropagation()
     if (filePath !== undefined) onOpenFile?.(filePath)
   }
+  // Keep Enter/Space on the focused path link from bubbling to the row's
+  // keydown handler, which would preventDefault() the key and toggle expand
+  // instead of activating the link — the keyboard analogue of openFile's
+  // stopPropagation. The native button still fires its own onClick from the key.
+  const fileLinkKeyDown = (event: KeyboardEvent<HTMLButtonElement>) => {
+    if (event.key === 'Enter' || event.key === ' ') event.stopPropagation()
+  }
   // Think reasoning is prose, not an input payload: expanded, it renders as
   // plain indented text (no IN/OUT card) and the inline summary — the body's
   // own first line — yields to avoid repeating itself.
@@ -176,6 +199,7 @@ export function ToolRow({
   // of losing it with the icon.
   return (
     <div className={css.root} data-variant={variant} data-tool={toolName} data-state={state}>
+      {status !== null && <span className={css.visuallyHidden}>{status}</span>}
       <DisclosureRow
         rowClassName={css.row}
         leadingClassName={css.leading}
@@ -198,6 +222,7 @@ export function ToolRow({
                 type="button"
                 className={css.fileLink}
                 onClick={openFile}
+                onKeyDown={fileLinkKeyDown}
               >
                 {summaryText}
               </button>

packages/client/ui-conversation/src/client/locales.ts

@@ -77,6 +77,9 @@ export const zh = {
   'bash.running': '运行中',
   'bash.failed': '失败',
   'bash.stopped': '已停止',
+  'row.running': '运行中',
+  'row.failed': '失败',
+  'row.stopped': '已停止',
   'queue.count': '{n} 条排队消息',
   'queue.edit': '编辑排队消息',
   'queue.edit.unsupported': '包含非文本内容，暂不支持编辑',
@@ -171,6 +174,9 @@ export const en = {
   'bash.running': 'Running',
   'bash.failed': 'Failed',
   'bash.stopped': 'Stopped',
+  'row.running': 'Running',
+  'row.failed': 'Failed',
+  'row.stopped': 'Stopped',
   'queue.count': '{n} queued messages',
   'queue.edit': 'Edit queued message',
   'queue.edit.unsupported': 'Contains non-text content; editing is not supported yet',

packages/client/ui-conversation/src/client/toolviews/search-row.tsx

@@ -48,7 +48,10 @@ export function SearchRow({ toolName, block, inspect, t }: SearchRowProps) {
       // A settled call with no search card (errored search, nested run_code
       // sub-dispatch, legacy generic result) has its text nowhere else to go;
       // ToolRow's Output section carries it, and errorSummary its first line.
-      output={search === null ? model.output : null}
+      // When a card is present ToolRow renders it instead of the output, so
+      // passing model.output unconditionally is safe and keeps the four card
+      // rows symmetric.
+      output={model.output}
       errorSummary={model.errorSummary}
       search={search}
       state={model.state}