fix(web): label only the first prompt row with the working directory

A multi-line command repeated the cwd label on every prompt row, which
states something the view does not know: it carries ONE working directory —
where the call started — and a `cd` in the command moves later lines
elsewhere. `cd ~` then `ls` rendered both rows labelled with the session
workspace while `ls` actually listed the home directory.

The label now appears on the first row only, and later rows keep a bare `$`
so they still read as prompts. Same reasoning as the run-state dot: neither
a per-line directory nor a per-line exit status exists to report.

The built-bundle snapshot records the effect on fixture turn 60's two-line
command (`fixture echo done` becomes `$ echo done`).

.agents/notes/implemented/feature/2026-07-28-web-terminal-card.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 .agents/notes/implemented/feature/2026-07-28-web-terminal-card.md
-2026-07-28-web-terminal-card.md: 8e4701b49373af3495c6f424c4ae2777f5bfcb75
-2026-07-28-web-terminal-card.zh.md: 07341ca942864281390f3820db88388fd61cef0e
+2026-07-28-web-terminal-card.md: 4bf5ee4e7899dceacbc56aced3289647ee42cd82
+2026-07-28-web-terminal-card.zh.md: a7baf5a84364994e938f7c12c368c8202832544a

.agents/notes/implemented/feature/2026-07-28-web-terminal-card.md

@@ -16,7 +16,7 @@ The Web client ignored it. `packages/client/ui-conversation/src/client/contract/
 
 The component's contract:
 
-- **Prompt lines, one per command line.** Each line of the command gets its own row: label, then that line verbatim. A `command` carrying two shell commands on two lines therefore reads as the two commands it is, instead of collapsing into one ellipsized row. The label is the cwd's last path segment, or `~` when the cwd equals the `home` prop — a browser has no `$HOME`, so the caller supplies the absolute home directory and the collapse simply does not apply without it. A view with no cwd renders a plain `$`. A trailing newline is a terminator, not an empty final command.
+- **Prompt lines, one per command line.** Each line of the command gets its own row: label, then that line verbatim. A `command` carrying two shell commands on two lines therefore reads as the two commands it is, instead of collapsing into one ellipsized row. The label is the cwd's last path segment, or `~` when the cwd equals the `home` prop — a browser has no `$HOME`, so the caller supplies the absolute home directory and the collapse simply does not apply without it. A view with no cwd renders a plain `$`. A trailing newline is a terminator, not an empty final command. Only the FIRST row carries the label: the view knows one working directory — where the call started — and a later line may run somewhere else entirely, since a `cd` in the command is enough to move it. Repeating the label down the rows would state a directory per line that nothing here knows, which is the same reason the run-state dot appears once. Later rows keep a bare `$` so they still read as prompts.
 - **One run-state dot for the call, on the first row.** `StateDot` in three of its four states: the chase while running, red for the exit status that also renders the pill, green for a clean settle — the same indicator a tool row's leading icon uses, so a row and its own card cannot disagree about one command. The dot exists because the first question a reader has about a shell command is whether it is still running, and without it that had to be inferred from the absence of output — which a settled command producing no output also looks like. It sits out of flow in a gutter reserved to the left of the card surface, so it neither indents its command nor depends on the command's own text metrics to line up with it. Exactly one dot, whatever the line count: the exit status the view carries is the whole call's, and bash reports no per-command status, so a dot per line would assert of a line that succeeded inside a failing call that the line itself failed. The single visually hidden text label carries the same scope, since `StateDot` is `aria-hidden` and one label per row would read to assistive technology as several distinct outcomes.
 - **No soft wrapping.** Output lines are `white-space: pre` inside a horizontally scrolling box. Column alignment survives; a long line scrolls instead of folding.
 - **Height cap with an expand control.** Output longer than `DEFAULT_TERMINAL_MAX_LINES` (16) lines shows `ceil(max/2)` head lines plus the remaining tail lines, with a button in between that reports the hidden count and expands. The count is of parsed lines after the trailing output terminator is dropped, so an N-line output ending in a newline is N lines. The split arithmetic is the same as the TUI transcript's collapsed tool card (`packages/ui/tui/src/components/transcript.ts`), so one command's head and tail slices agree between the two front ends.

.agents/notes/implemented/feature/2026-07-28-web-terminal-card.zh.md

@@ -16,7 +16,7 @@ Web client 却对它视而不见。`packages/client/ui-conversation/src/client/c
 
 该组件的契约：
 
-- **提示符行，每条命令行一行。** 命令的每一行各占一行：标签，其后原样跟随该行。因此一个在两行上承载两条 shell 命令的 `command` 就读作它本身的两条命令，而不是被压成一行并省略号截断。标签取 cwd 的最后一段路径，当 cwd 等于 `home` prop 时取 `~`——浏览器没有 `$HOME`，因此由调用方提供绝对家目录，不提供时该折叠不生效。视图不带 cwd 时渲染一个纯 `$`。末尾换行是终止符，不是一条空的末命令。
+- **提示符行，每条命令行一行。** 命令的每一行各占一行：标签，其后原样跟随该行。因此一个在两行上承载两条 shell 命令的 `command` 就读作它本身的两条命令，而不是被压成一行并省略号截断。标签取 cwd 的最后一段路径，当 cwd 等于 `home` prop 时取 `~`——浏览器没有 `$HOME`，因此由调用方提供绝对家目录，不提供时该折叠不生效。视图不带 cwd 时渲染一个纯 `$`。末尾换行是终止符，不是一条空的末命令。只有**第一行**携带该标签：视图只知道一个工作目录——调用开始处的那个——而后面的行完全可能在别处运行，命令里一个 `cd` 就足以改变它。把标签在各行重复，等于陈述一个此处无人知晓的逐行目录，这与运行状态点只出现一次是同一个理由。其余行保留一个裸 `$`，因此它们仍读作提示符。
 - **整次调用一枚运行状态点，位于第一行。** 它是 `StateDot` 四种状态中的三种：运行期间为追逐动画，与渲染状态徽章相同的退出状态为红色，干净落定为绿色——与工具行行首图标使用同一个指示器，因此一行与其自身的卡片不可能对同一条命令产生分歧。该状态点存在的理由是：读者对一条 shell 命令的第一个问题就是它是否仍在运行；没有它时，这一点只能从「没有输出」推断，而一条落定后无输出的命令看起来也一样。它以脱离文档流的方式落在卡片表面左侧预留的落区里，因此既不会缩进其命令，也不依赖命令自身的文本度量来与之对齐。无论有多少行，都只有一枚：视图携带的退出状态属于整次调用，而 bash 不报告逐条命令的状态，因此每行一枚状态点就等于在断言——一条在失败调用中其实成功了的命令行自身失败了。那一处视觉隐藏的文本标签具有相同的作用域，因为 `StateDot` 是 `aria-hidden`，而每行一个标签会被辅助技术读成好几个各自独立的结果。
 - **不软换行。** 输出行使用 `white-space: pre`，置于横向滚动的容器内。列对齐得以保留；长行滚动，而非折行。
 - **高度上限与展开控件。** 输出超过 `DEFAULT_TERMINAL_MAX_LINES`（16）行时，显示 `ceil(max/2)` 行首部加余下的尾部行数，中间是一个按钮，报告被隐藏的行数并可展开。计数针对的是剥除输出末尾终止符之后解析出的行，因此以换行结尾的 N 行输出就是 N 行。切分算法与 TUI transcript 折叠态工具卡片（`packages/ui/tui/src/components/transcript.ts`）完全一致，因此同一条命令的首尾切片在两个前端之间吻合。