fix(web): bound the SGR state and follow real terminal widths

Nine findings, one critical. Terminal cases verified in a real terminal first.

CRITICAL: cells held the accumulated SGR history, so every state boundary
re-emitted the whole chain — output switching color without a full reset
emitted O(n^2) characters. Measured: 3200 such cells produced 25 MB, and the
reviewer's ~90 KB alternating-color case is well under bash's own output cap.
State is now a normalized record (foreground, background, attribute set) with
one canonical sequence per boundary, so the emitted text is linear in cells;
the 90 KB case parses in 36 ms. That also makes the attribute closers every
chalk-based tool writes actually close: `\x1b[1mbold\x1b[22mplain` leaves the
following write PLAIN, which a real terminal confirms.

Width follows emoji presentation, not the U+2600-U+27BF block: `A✓B` redrawn
with `XY` shows `XYB`, so the check every progress line writes is ONE column.
Taking the block as wide misaligned exactly the output this card exists for.

Writing over either half of a wide pair blanks the other, since a terminal
cannot leave one cell of a two-cell glyph standing.

`line\n\x1b[0m` does not end in a newline as a string yet its last parsed line
holds nothing visible, so the terminator check now reads the parsed lines — it
had added a blank row and inflated the collapse count.

A line with no cursor movement no longer builds a column buffer at all; only
its SGR is folded, so an `ls -R` or a 5k-line log allocates nothing per
character.

The `.terminalDescription` rule had been inserted into an existing grouped
selector, silently giving `.codeBody` description typography and changing its
bottom margin from 4px to 0 — a pre-existing surface this PR does not own.
Split out, `.codeBody`'s margin restored.

Three comments contradicted their code: the fixture's exit-marker line (still
claiming recovery from a marker deliberately removed), `bash-sample`'s header
(still routing a click to the details panel, and calling the consumer's cap the
block's own), and a DetailsPanel comment stacked above the wrong rule. The
ui-primitives README documented only the CR/BS half of the replay, so a reader
would expect `OK0%` where `100%\r\x1b[KOK` renders `OK`.

.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: f580e3c8c17b8701ae223ea3ed910fa57b915278
-2026-07-28-web-terminal-card.zh.md: eb48fd3a1bcff9599b138630113460fe867a6aef
+2026-07-28-web-terminal-card.md: 14896b1d88e5cfd2e4c58830c7a1bca1e54ed823
+2026-07-28-web-terminal-card.zh.md: 16c9004f8f80b720b25b76ba5c04f308b0fccbaf

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

@@ -20,7 +20,7 @@ The component's contract:
 - **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 the card reserves as its OWN left padding, so it neither indents its command nor depends on the command's text metrics to line up. The reservation is padding rather than margin because every render site rewrites `margin` wholesale to set its own indent, which silently cancelled a margin-based gutter and let a container clip the dot. 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.
-- **ANSI color.** `anser` splits the SGR runs; `ui-primitives/src/ansi.ts` resolves each run into an inline style rendered as React spans. A foreground-only run maps the basic 16 colors onto `--dsw-*` theme tokens so authored color stays legible under both themes; a run that paints its own background keeps anser's literal rgb for both so its intended contrast survives, as do 256-palette, truecolor, and the two basic colors this design system has no token for. Sequences that carry no color (OSC strings, non-CSI escapes, inert C0 controls) are stripped before parsing so they never reach the DOM as literal characters. Cursor movements resolve before that strip, into a per-line column buffer rather than by string surgery, because carriage return and backspace only MOVE the cursor — neither erases anything, so what a reader sees is whatever each column last had written to it. `100%` then a carriage return and `OK` shows `OK0%`, since the redraw is shorter than the frame beneath it; a trailing `abc` plus a backspace still shows `abc`, since nothing overwrote the `c`; `abc` plus two backspaces and `XY` shows `aXY`. Each of these was checked against a real terminal, because the earlier truncate-and-delete approximations looked right and were not. SGR state is stamped per column as a terminal stores it per cell, so a partial overwrite keeps each surviving character's own color: red `bad`, three backspaces, then `ok` shows `okd` with the `d` still red. A CSI sequence occupies no column and changes only the state later writes are stamped with, which is also why a carriage return does not reset color, and why SGR state threads from one line to the next rather than closing at each newline. Erase-in-line is part of the same replay, because `\r\x1b[K` is the single idiom every spinner and progress bar writes — modelling the `\r` alone left the previous frame's tail standing, which is text the terminal never showed. Only `m` accumulates into a cell's style; a cursor or erase sequence must not, or the state string grows per redraw and emits boundaries anser has to discard. A run also has to CLOSE: the replay converges to the state the scan ended in, not the last written cell's, because a reset after the final write changes no cell yet ends the run — without that a line finishing in `\x1b[0m` leaked its color onto every later line. The cursor advances by terminal columns, so a tab reaches the next 8-column stop, a wide character takes two (its spacer blanking rather than closing the gap once the lead cell is overwritten), and a combining mark takes none: `a\tb` then a redraw of `XY` shows `XY      b`, since a two-character redraw cannot reach column 8.
+- **ANSI color.** `anser` splits the SGR runs; `ui-primitives/src/ansi.ts` resolves each run into an inline style rendered as React spans. A foreground-only run maps the basic 16 colors onto `--dsw-*` theme tokens so authored color stays legible under both themes; a run that paints its own background keeps anser's literal rgb for both so its intended contrast survives, as do 256-palette, truecolor, and the two basic colors this design system has no token for. Sequences that carry no color (OSC strings, non-CSI escapes, inert C0 controls) are stripped before parsing so they never reach the DOM as literal characters. Cursor movements resolve before that strip, into a per-line column buffer rather than by string surgery, because carriage return and backspace only MOVE the cursor — neither erases anything, so what a reader sees is whatever each column last had written to it. `100%` then a carriage return and `OK` shows `OK0%`, since the redraw is shorter than the frame beneath it; a trailing `abc` plus a backspace still shows `abc`, since nothing overwrote the `c`; `abc` plus two backspaces and `XY` shows `aXY`. Each of these was checked against a real terminal, because the earlier truncate-and-delete approximations looked right and were not. SGR state is stamped per column as a terminal stores it per cell, so a partial overwrite keeps each surviving character's own color: red `bad`, three backspaces, then `ok` shows `okd` with the `d` still red. A CSI sequence occupies no column and changes only the state later writes are stamped with, which is also why a carriage return does not reset color, and why SGR state threads from one line to the next rather than closing at each newline. Erase-in-line is part of the same replay, because `\r\x1b[K` is the single idiom every spinner and progress bar writes — modelling the `\r` alone left the previous frame's tail standing, which is text the terminal never showed. Only `m` accumulates into a cell's style; a cursor or erase sequence must not, or the state string grows per redraw and emits boundaries anser has to discard. SGR is held per cell as a NORMALIZED record (foreground, background, attribute set), not as the sequence history: accumulating raw sequences made every state boundary re-emit the whole chain, so output that switches color without a full reset emitted O(n^2) characters — 3200 such cells produced 25 MB and a `RangeError` well under bash's own output cap. The record also lets the attribute closers every chalk-based tool writes (`39`, `49`, `22`, `24`, …) actually close their attribute, and each boundary emits one canonical sequence for the state it opens. A run also has to CLOSE: the replay converges to the state the scan ended in, not the last written cell's, because a reset after the final write changes no cell yet ends the run — without that a line finishing in `\x1b[0m` leaked its color onto every later line. The cursor advances by terminal columns, so a tab reaches the next 8-column stop, a wide character takes two (its spacer blanking rather than closing the gap once the lead cell is overwritten), and a combining mark takes none. Width follows emoji PRESENTATION rather than the U+2600-U+27BF block: `\u2713`, the check every progress line writes, is one column, so treating the block as wide misaligned exactly the output this card exists for. Writing over either half of a wide pair blanks the other, since a terminal cannot leave one cell of a two-cell glyph standing: `a\tb` then a redraw of `XY` shows `XY      b`, since a two-character redraw cannot reach column 8.
 - **Exit status and copy.** A non-zero exit code or a signal renders a status pill, matching the exit-status distinction the bash tool's own renderer draws; a clean exit renders none, and settled empty output renders a dimmed placeholder — judged on the parsed lines the card renders, not on the raw text, since output that is only escapes or control bytes survives a `trim()` yet parses to nothing visible and would otherwise draw blank rows plus a copy control for invisible bytes. The copy control copies the raw output text, not the rendered tree, so the prompt line and the pill stay out of the clipboard.
 
 Geometry, radius, and fonts mirror `CodeBlock`, so a terminal card and a fenced code block match visually; `white-space: pre` plus horizontal scroll is the deliberate divergence. The clipboard write both components need moved out of `CodeBlock` into a package-internal `src/clipboard.ts`, unexported so it stays an implementation detail of the two blocks.

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

@@ -20,7 +20,7 @@ Web client 却对它视而不见。`packages/client/ui-conversation/src/client/c
 - **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以**自身左内边距**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。该预留用 padding 而非 margin，是因为每个渲染点都会整条重写 `margin` 来设定自己的缩进——那会静默取消基于 margin 的落区，并让容器把状态点裁掉。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。
-- **ANSI 颜色。** `anser` 切分 SGR 分段；`ui-primitives/src/ansi.ts` 把每段解析为内联样式，渲染成 React span。只设前景色的分段把基本 16 色映射到 `--dsw-*` 主题 token，使作者指定的颜色在两种主题下都可读；自行绘制背景的分段则前后景都保留 anser 给出的字面 rgb，以保住它意图中的对比度，256 色板、truecolor 以及本设计系统没有对应 token 的两种基本色同样如此。不承载颜色的转义序列（OSC 串、非 CSI 转义、无显示意义的 C0 控制符）在解析前被剥除，因此绝不会以字面字符抵达 DOM。光标移动在该剥除之前先行结算，且落在逐行的列缓冲里而不是靠字符串手术，因为回车与退格**只移动**光标——两者都不擦除任何东西，所以读者看到的就是每一列最后被写入的内容。`100%` 后接回车再接 `OK` 显示为 `OK0%`，因为这次重绘比它下面的帧更短；末尾 `abc` 加一个退格仍显示 `abc`，因为没有任何东西覆盖过那个 `c`；`abc` 加两个退格再接 `XY` 显示 `aXY`。这些用例都对照真实终端核实过，因为先前「截断加删除」的近似看起来是对的，实际并不对。SGR 状态按列打戳，与终端按单元格存储颜色的方式一致，因此部分覆盖会保留每个存活字符自身的颜色：红色 `bad`、三个退格、再写 `ok`，显示为 `okd` 且那个 `d` 仍是红的。CSI 序列不占列，只改变后续写入被打上的状态——这也正是回车不会重置颜色的原因，以及 SGR 状态会从一行延续到下一行、而不是在每个换行处关闭的原因。行内擦除属于同一次重放，因为 `\r\x1b[K` 是每个 spinner 与进度条都会写的同一个惯用法——只建模 `\r` 会让上一帧的尾巴留在原处，那是终端从未显示过的文本。只有 `m` 会累加进单元格样式；光标或擦除序列不能累加，否则状态串会随每次重绘线性增长，并发出 anser 只能丢弃的边界。一个分段也必须**收束**：重放收敛到扫描结束时的状态，而不是最后一个被写入单元格的状态——因为最后一次写入之后的 reset 不改变任何单元格，却结束了该分段；没有这一步，以 `\x1b[0m` 结尾的行会把颜色泄漏到其后所有行。光标按终端列推进，因此制表符前进到下一个 8 列制表位、宽字符占两列（其续列在首列被覆盖后变为空白而非合拢），组合标记不占列：`a\tb` 之后用 `XY` 重绘显示为 `XY      b`，因为两个字符的重绘到不了第 8 列。
+- **ANSI 颜色。** `anser` 切分 SGR 分段；`ui-primitives/src/ansi.ts` 把每段解析为内联样式，渲染成 React span。只设前景色的分段把基本 16 色映射到 `--dsw-*` 主题 token，使作者指定的颜色在两种主题下都可读；自行绘制背景的分段则前后景都保留 anser 给出的字面 rgb，以保住它意图中的对比度，256 色板、truecolor 以及本设计系统没有对应 token 的两种基本色同样如此。不承载颜色的转义序列（OSC 串、非 CSI 转义、无显示意义的 C0 控制符）在解析前被剥除，因此绝不会以字面字符抵达 DOM。光标移动在该剥除之前先行结算，且落在逐行的列缓冲里而不是靠字符串手术，因为回车与退格**只移动**光标——两者都不擦除任何东西，所以读者看到的就是每一列最后被写入的内容。`100%` 后接回车再接 `OK` 显示为 `OK0%`，因为这次重绘比它下面的帧更短；末尾 `abc` 加一个退格仍显示 `abc`，因为没有任何东西覆盖过那个 `c`；`abc` 加两个退格再接 `XY` 显示 `aXY`。这些用例都对照真实终端核实过，因为先前「截断加删除」的近似看起来是对的，实际并不对。SGR 状态按列打戳，与终端按单元格存储颜色的方式一致，因此部分覆盖会保留每个存活字符自身的颜色：红色 `bad`、三个退格、再写 `ok`，显示为 `okd` 且那个 `d` 仍是红的。CSI 序列不占列，只改变后续写入被打上的状态——这也正是回车不会重置颜色的原因，以及 SGR 状态会从一行延续到下一行、而不是在每个换行处关闭的原因。行内擦除属于同一次重放，因为 `\r\x1b[K` 是每个 spinner 与进度条都会写的同一个惯用法——只建模 `\r` 会让上一帧的尾巴留在原处，那是终端从未显示过的文本。只有 `m` 会累加进单元格样式；光标或擦除序列不能累加，否则状态串会随每次重绘线性增长，并发出 anser 只能丢弃的边界。SGR 按单元格以**归一化记录**保存（前景、背景、属性集合），而不是序列历史：累积原始序列会让每个状态边界重新发射整条链，因此不做完整 reset 的换色输出会发射 O(n^2) 个字符——3200 个这样的单元格产生 25 MB 并最终 `RangeError`，远低于 bash 自身的输出上限。该记录也让所有 chalk 系工具写出的属性闭合码（`39`、`49`、`22`、`24` 等）真正闭合其属性，且每个边界只为它开启的状态发射一条规范序列。一个分段也必须**收束**：重放收敛到扫描结束时的状态，而不是最后一个被写入单元格的状态——因为最后一次写入之后的 reset 不改变任何单元格，却结束了该分段；没有这一步，以 `\x1b[0m` 结尾的行会把颜色泄漏到其后所有行。光标按终端列推进，因此制表符前进到下一个 8 列制表位、宽字符占两列（其续列在首列被覆盖后变为空白而非合拢），组合标记不占列。宽度依据 emoji **presentation** 而非 U+2600–U+27BF 整个区块：`\u2713`——每条进度行都会写的对勾——只占一列，把该区块整体当作双宽恰好会错位这张卡片赖以存在的那类输出。写入宽字符对的任一半都会把另一半清成空白，因为终端无法让一个双格字形只留下一格：`a\tb` 之后用 `XY` 重绘显示为 `XY      b`，因为两个字符的重绘到不了第 8 列。
 - **退出状态与复制。** 非零退出码或信号渲染一枚状态徽章，与 bash 工具自身渲染器所作的退出状态区分一致；干净退出不渲染徽章，落定后的空输出渲染一处变暗的占位文字——该判定读的是卡片实际渲染的解析行，而非原始文本，因为只含转义或控制字节的输出能通过 `trim()` 却解析不出任何可见内容，否则就会画出一片空行外加一个把不可见字节写进剪贴板的复制控件。复制控件复制的是原始输出文本而非渲染后的树，因此提示符行与徽章不会进入剪贴板。
 
 几何尺寸、圆角与字体沿用 `CodeBlock`，因此终端卡片与围栏代码块在视觉上一致；`white-space: pre` 加横向滚动是有意的分歧。两个组件都需要的剪贴板写入从 `CodeBlock` 中提取到包内部的 `src/clipboard.ts`，不对外导出，因此它仍是这两个块的实现细节。