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-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: 43266c05baca8d78406f35106db82ffa8e48f744
-README.zh.md: ff3bc69492e5124b00528ae52280898d18f3bd65
+README.md: 6e30892b3fb657d22a06b74f9176c04552a969ff
+README.zh.md: e194f982f399c4c11749a04a28b10e189adc33bf

packages/client/ui-primitives/README.md

@@ -2,7 +2,7 @@
 
 English | [中文](README.zh.md)
 
-Pure React atoms (zero cordis): StateDot, ic_ds_* icons, Button/Pill/Menu/Modal/Input, the markdown family (MessageText/MarkdownText/JsonBlock), the read-only JsonTree inspector, the `useAnchoredMaxHeight` hook that clamps a bottom-anchored overlay to the viewport space above its anchor (re-measured on resize, scroll, and a caller-supplied dependency), TerminalBlock, DiffBlock, SearchBlock, and WebBlock. Contract: api-contracts v3 §8.
+Pure React atoms (zero cordis): StateDot, ic_ds_* icons, Button/Pill/Menu/Modal/Input, the markdown family (MessageText/MarkdownText/JsonBlock), the read-only JsonTree inspector, the `useAnchoredMaxHeight` hook that clamps a bottom-anchored overlay to the viewport space above its anchor (re-measured on resize, scroll, and a caller-supplied dependency), TerminalBlock, DiffBlock, ReadBlock, SearchBlock, and WebBlock. Contract: api-contracts v3 §8.
 
 ## Markdown rendering
 
@@ -12,6 +12,10 @@ Pure React atoms (zero cordis): StateDot, ic_ds_* icons, Button/Pill/Menu/Modal/
 
 `TerminalBlock` renders a shell command as a terminal surface: one prompt row per line of the command (the shortened `cwd` label on the first row only, since the view knows one working directory and a `cd` moves later lines elsewhere, then that line), the command's output, a status pill for a non-zero exit code or a terminating signal, and a copy control that writes the raw `output` prop. A run-state `StateDot` marks the call once, on the first row, out of flow in a gutter the card reserves as its own left padding, so the dot sits inside the card box yet left of the prompt text. It reaches three of `StateDot`'s states — the chase while `running`, red for the same exit status that renders the pill, green otherwise — so a card states whether its command is still running rather than leaving that to be inferred from the presence of output; it carries one visually hidden text label because `StateDot` is `aria-hidden`. One dot regardless of line count is deliberate: the exit status is the whole call's, so a dot per line would claim a per-line outcome the view does not carry. Command text is `white-space: pre`, so repeated spaces, tabs, and an indented continuation render verbatim while the row stays single-line and ellipsizes. ANSI escape sequences are parsed with the `anser` runtime dependency into React spans; cursor movements replay into a per-line column buffer before inert controls are stripped, since carriage return and backspace only MOVE the cursor: `100%` + CR + `OK` alone shows `OK0%`, while the `\x1b[K` a spinner writes with its redraw erases the tail so `100%\r\x1b[KOK` shows `OK`. Erase-in-line is honored in all three parameter forms, the cursor advances by terminal columns (8-column tab stops, two for emoji and CJK, none for a combining mark), and SGR state is normalized per cell as a terminal stores it, threading across lines and closing at the state the line ended in; basic-16 foreground colors map onto `--dsw-*` tokens, while 256-palette and truecolor values pass through as literal rgb. Output keeps `white-space: pre` with horizontal scrolling, so column-aligned output holds its alignment instead of soft-wrapping, and collapses to a head slice plus a tail slice past `maxLines` (default 16, the TUI transcript's split arithmetic) behind an expand button. Rationale: [the web terminal card note](../../../.agents/notes/implemented/feature/2026-07-28-web-terminal-card.md).
 
+## Read rendering
+
+`ReadBlock` renders a returned file window as a line-numbered, syntax-highlighted code surface: a bold path (or presenter-supplied title) banner with a copy control, then the content lines with their file line numbers in a gutter (a windowed read keeps the file's own numbering, so a read past an offset starts above 1). A `totalLines` exceeding the window count draws a `showing N of M` note, and the body collapses to a head slice plus a tail slice past `maxLines` (default 16, the TerminalBlock split arithmetic) behind an expand button. Highlighting runs through the same shiki path as `CodeBlock`. Rationale: [the web read card note](../../../.agents/notes/implemented/feature/2026-07-30-web-read-card.md).
+
 ## Diff rendering
 
 `DiffBlock` renders a file mutation as an inline diff surface: one bold path header per file, the removed lines (`- `, error token) above the added lines (`+ `, success token), a `⋯` gap before a same-file second hunk, and a dim `└ +A -R · N file(s)` footer. Lines are `white-space: pre` with horizontal scrolling, so a source line holds its indentation instead of soft-wrapping, and the body collapses to a head slice plus a tail slice past `maxLines` (default 16, `TerminalBlock`'s split arithmetic) behind an expand button. A create (`oldText: null`) has no removed side. The copy control writes the prefixed diff text (path headers, `- `/`+ ` lines, the gap) so a multi-file copy stays attributable, and floats in the top-right corner rather than on a banner row of its own. Geometry mirrors `CodeBlock`/`TerminalBlock`. The `+`/`-` block form mirrors the TUI transcript's diff card so a diff reads the same across front ends. Rationale: [the web diff card note](../../../.agents/notes/implemented/feature/2026-07-30-web-diff-card.md).

packages/client/ui-primitives/README.zh.md

@@ -2,7 +2,7 @@
 
 [English](README.md) | 中文
 
-纯 React 原子组件（零 cordis）：StateDot、ic_ds_* 图标、Button/Pill/Menu/Modal/Input、markdown 家族（MessageText/MarkdownText/JsonBlock）、只读 JsonTree 检查器、`useAnchoredMaxHeight` hook（把底部锚定的浮层高度收敛到锚点上方的视口空间，并在 resize、scroll 与调用方提供的依赖变化时重新测量）、TerminalBlock、DiffBlock、SearchBlock，以及 WebBlock。契约：api-contracts v3 §8。
+纯 React 原子组件（零 cordis）：StateDot、ic_ds_* 图标、Button/Pill/Menu/Modal/Input、markdown 家族（MessageText/MarkdownText/JsonBlock）、只读 JsonTree 检查器、`useAnchoredMaxHeight` hook（把底部锚定的浮层高度收敛到锚点上方的视口空间，并在 resize、scroll 与调用方提供的依赖变化时重新测量）、TerminalBlock、DiffBlock、ReadBlock、SearchBlock，以及 WebBlock。契约：api-contracts v3 §8。
 
 ## Markdown 渲染
 
@@ -11,6 +11,10 @@
 
 `TerminalBlock` 将一条 shell 命令渲染为终端表层：命令的每一行各占一个提示行（缩短后的 `cwd` 标签只出现在第一行，因为视图只知道一个工作目录，而一个 `cd` 就会让后面的行去到别处，标签之后是该行）、命令输出、非零退出码或终止信号对应的状态胶囊，以及写入原始 `output` prop 的复制控件。一枚运行状态 `StateDot` 为整次调用标记一次，位于第一行，以脱离文档流的方式落在卡片以自身左内边距预留的落区中，因此它位于卡片盒之内、提示文字之左。它用到 `StateDot` 的三种状态——`running` 期间为追逐动画，与渲染状态胶囊相同的退出状态为红色，其余为绿色——因此卡片直接陈述其命令是否仍在运行，而不是让人从有无输出中推断；由于 `StateDot` 是 `aria-hidden`，它携带一处视觉隐藏的文本标签。无论多少行都只有一枚状态点是有意为之：退出状态属于整次调用，因此每行一枚就会声称一个视图并不携带的逐行结果。命令文本使用 `white-space: pre`，因此重复空格、制表符与缩进续行都原样呈现，同时该行仍保持单行并以省略号截断。ANSI 转义序列通过运行时依赖 `anser` 解析为 React span；光标移动在剥除无显示意义控制符之前先重放进逐行的列缓冲，因为回车与退格**只移动**光标：单是 `100%` 加回车再加 `OK` 显示为 `OK0%`，而 spinner 随重绘写出的 `\x1b[K` 会擦掉尾巴，因此 `100%\r\x1b[KOK` 显示为 `OK`。行内擦除的三种参数形式都被遵循，光标按终端列推进（8 列制表位；emoji 与 CJK 占两列；组合标记不占列），SGR 状态按单元格归一化存储，与终端一致，并跨行延续、在行结束时的状态处收束；基础 16 色前景色映射到 `--dsw-*` token，而 256 色板与真彩色值按字面 rgb 透传。输出保持 `white-space: pre` 并支持横向滚动，因此按列对齐的输出保留其对齐而不会软换行；超过 `maxLines`（默认 16，与 TUI 转录相同的切分算法）时折叠为头部切片加尾部切片，由展开按钮控制。原理：[Web 终端卡片笔记](../../../.agents/notes/implemented/feature/2026-07-28-web-terminal-card.md)。
 
+## Read 渲染
+
+`ReadBlock` 将返回的文件窗口渲染为带行号、语法高亮的代码表层：一个粗体路径（或 presenter 提供的标题）横幅加复制控件，其下是内容行，行号槽里是文件自身的行号（窗口化的 read 保留文件本身的编号，因此偏移之后的 read 从大于 1 处起始）。`totalLines` 超过窗口行数时画出 `showing N of M` 提示；超过 `maxLines`（默认 16，与 TerminalBlock 相同的切分算法）时折叠为头部切片加尾部切片，由展开按钮控制。高亮走与 `CodeBlock` 相同的 shiki 路径。原理：[Web read 卡片笔记](../../../.agents/notes/implemented/feature/2026-07-30-web-read-card.md)。
+
 ## Diff 渲染
 
 `DiffBlock` 将一次文件改动渲染为内联 diff 表层：每个文件一个粗体路径头、删除行（`- `，error token）在新增行（`+ `，success token）之上、同文件第二个 hunk 前一个 `⋯` gap，以及暗色 `└ +A -R · N file(s)` 页脚。各行使用 `white-space: pre` 并横向滚动，因此源码行保留其缩进而不软换行；超过 `maxLines`（默认 16，与 `TerminalBlock` 相同的切分算法）时折叠为头部切片加尾部切片，由展开按钮控制。新建（`oldText: null`）没有删除侧。复制控件写入带前缀的 diff 文本（路径头、`- `/`+ ` 行、gap），使多文件复制保持可归属，并浮在右上角而非占据自己的 banner 行。几何镜像 `CodeBlock`/`TerminalBlock`。`+`/`-` 块形式镜像 TUI 转录的 diff 卡片，使 diff 在两个前端读起来一致。原理：[Web diff 卡片笔记](../../../.agents/notes/implemented/feature/2026-07-30-web-diff-card.md)。