Merge remote-tracking branch 'origin/master' into fix/landlock-runner-failure-classification

2026-08-04 13:54:37 +08:00
parent b0f33f13f4 4b591c0abc
commit 0cd1611023
41 changed files with 775 additions and 265 deletions
--- a/packages/client/ui-conversation/README.i18n.yaml
+++ b/packages/client/ui-conversation/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-conversation/README.md
-README.md: 78572ba0ab3ce9475dba31dee8844017564e2a18
-README.zh.md: 7708e980e24f4ea4365fbbacd641a5be6c61b138
+README.md: 7d3a4b5fe07cc8858c2f2059e6f65b6e27602b4d
+README.zh.md: d93af91381157bb4e8e4b6a14ad00edecd505246
--- a/packages/client/ui-conversation/README.md
+++ b/packages/client/ui-conversation/README.md
@@ -22,7 +22,7 @@ Generic tool rows classify the built-in bash, read, search, write, edit, and run

 A tool call declaring the `terminal` render intent renders its command output inline, at both conversation render sites, through ui-primitives' `TerminalBlock`. `contract/terminal-card-model.ts` is the single derivation from the snapshot's `callView`/`resultView` pair, so the sites cannot disagree about a command, its cwd, or its exit status; it yields null — the generic path — for any other card tag, including one this client version does not know. Both sites therefore also show the card's run-state dot, which is the same `StateDot` semantic a tool row's leading icon carries, so a row and its own card always agree about one command's state. A multi-line command gets one prompt row per line, with the dot marking the call once on the first row — the exit status is the whole call's, so a dot per line would claim a per-line outcome bash does not report. The keyed `BashRow` carries the card resident below its summary row; since tool rows are no longer details-panel click targets, the card's copy and expand controls are the row's only interactions. The render-site fallback row keeps the card behind its existing expand control. Rows cap at `CHAT_TERMINAL_MAX_LINES` (8) against the panel's 16, which is what keeps a summary surface bounded — the panel stays the single-call reading surface. Inline output is licensed per render intent — the terminal and web cards, each with its own bound. A Bash execution failure that settles on the generic path instead exposes its original arguments and full error through the same bounded IN/OUT disclosure, while successful generic results such as a background-start acknowledgement remain summary-only ([decision](../../../.agents/notes/implemented/feature/2026-07-28-web-terminal-card.md)).

-A tool call declaring the `web` render intent renders its web retrieval inline, at both conversation render sites, through ui-primitives' `WebBlock`. `contract/web-card-model.ts` is the single derivation from the snapshot's `resultView`, mirroring the terminal card, so the sites cannot disagree about what a web call shows; it yields null — the generic path — for a running call, a non-web result view, a generic result view, a `card` tag this client version does not know, or a web card whose `kind` this client version does not know (a newer host's value, which the wire cannot be trusted to be `search` or `fetch`). The keyed `WebRow` registers one component under both `web_search` and `web_fetch`, discriminating on the tool name only for its icon and title; it composes the shared `ToolRow`, feeding the card as ToolRow's `web` body, so the retrieval is the row's collapsed-by-default expanded card (the same unified expand every card row has). A web-declaring tool without a keyed row lands on the `GenericToolCard` fallback, which routes the card through ToolRow the same way, and the details panel renders it at the primitive's full source allowance and, below the card, the flattened model-visible result content — a fetch body is readable only there, since its card carries only the URL and status. Rows cap at `CHAT_WEB_MAX_SOURCES` (8) against the panel's 16, the same summary-versus-reading split the terminal card draws ([decision](../../../.agents/notes/implemented/feature/2026-07-30-web-result-card-frontend.md)).
+A tool call declaring the `web` render intent renders its web retrieval inline, at both conversation render sites, through ui-primitives' `WebBlock`. `contract/web-card-model.ts` is the single derivation from the snapshot's `resultView`, mirroring the terminal card, so the sites cannot disagree about what a web call shows; it yields null — the generic path — for a running call, a non-web result view, a generic result view, a `card` tag this client version does not know, or a web card whose `kind` this client version does not know (a newer host's value, which the wire cannot be trusted to be `search` or `fetch`). The keyed `WebRow` registers one component under both `web_search` and `web_fetch`, discriminating on the tool name only for its icon and title; it composes the shared `ToolRow`, feeding the card as ToolRow's `web` body, so the retrieval is the row's collapsed-by-default expanded card (the same unified expand every card row has). A web-declaring tool without a keyed row lands on the `GenericToolCard` fallback, which routes the card through ToolRow the same way, and the details panel renders it and, below the card, the flattened model-visible result content — a fetch body is readable only there, since its card carries only the URL and status. Both render sites show the same complete source list — the one the tool returned and the model saw — bounded only by the card's own scroll container height, with no row-versus-panel cap ([decision](../../../.agents/notes/implemented/feature/2026-07-30-web-result-card-frontend.md), [source scroll](../../../.agents/notes/implemented/feature/2026-08-03-web-search-source-scroll.md)).

 A `read` call declaring the `read` render intent renders the returned file window inline, at both conversation render sites, through ui-primitives' `ReadBlock` — the line-numbered, syntax-highlighted content the tool projects. `contract/read-card-model.ts` is the single derivation from the snapshot's `resultView`; the read card is result-side only (a call carries no file content until `execute` returns), so a running read shows its summary alone and it yields null — the generic path — for a non-read result view or a `card` tag this client version does not know. The keyed `ReadRow` composes the shared `ToolRow`, feeding the card as ToolRow's `read` body, so it is the row's collapsed-by-default expanded card; the summary stays a path link that opens the file through the host. The render-site fallback and the details panel are read-aware too. Rows cap at `CHAT_READ_MAX_LINES` (8) against the panel's 16 ([decision](../../../.agents/notes/implemented/feature/2026-07-30-web-read-card-frontend.md)).

--- a/packages/client/ui-conversation/README.zh.md
+++ b/packages/client/ui-conversation/README.zh.md
@@ -20,7 +20,7 @@ Think 行默认保持折叠，并在不展开思维链的情况下暴露实时

 声明 `terminal` 渲染意图的工具调用，会在两个对话渲染点上都通过 ui-primitives 的 `TerminalBlock` 内联渲染其命令输出。`contract/terminal-card-model.ts` 是从快照的 `callView`／`resultView` 对推导的唯一位置，因此两个渲染点不可能在命令、cwd 或退出状态上产生分歧；对任何其他 card 标签——包括当前客户端版本不认识的标签——它返回 null，落回通用路径。因此两个渲染点也都显示卡片的运行状态点，它与工具行行首图标承载同一套 `StateDot` 语义，所以一行与其自身的卡片对同一条命令的状态总是一致。多行命令的每一行各占一个提示行，状态点只在第一行为整次调用标记一次——退出状态属于整次调用，因此每行一枚就会声称一个 bash 并不报告的逐行结果。键控的 `BashRow` 把卡片常驻在摘要行下方；由于工具行已不再是详情面板的点击目标，卡片的复制与展开控件就是该行唯一的交互。渲染点兜底行则保持其既有的展开控件。行的上限是 `CHAT_TERMINAL_MAX_LINES`（8），面板为 16，正是这一点让摘要面保持有界——面板仍是单次调用的阅读面。内联输出按渲染意图开放——终端卡片与 web 卡片，各有自己的上限。若 Bash 执行失败时落在通用路径，则改用同样有界的 IN/OUT 展开区暴露原始参数和完整错误；后台启动确认等成功的通用结果仍只显示摘要（[决策](../../../.agents/notes/implemented/feature/2026-07-28-web-terminal-card.md)）。

-声明 `web` 渲染意图的工具调用，会在两个对话渲染点上都通过 ui-primitives 的 `WebBlock` 内联渲染其 web 检索。`contract/web-card-model.ts` 是从快照的 `resultView` 推导的唯一位置，镜像终端卡片，因此两个渲染点不可能对一次 web 调用的显示产生分歧；对运行中的调用、非 web 的 result view、generic result view、本客户端版本不认识的 `card` 标签，或本客户端版本不认识 `kind` 的 web 卡片（更新的 host 发来的值，wire 上不可信其为 `search` 或 `fetch`），它返回 null，落回通用路径。键控的 `WebRow` 把一个组件注册在 `web_search` 与 `web_fetch` 两个键下，仅根据工具名判别以选取图标与标题；它组合共享的 `ToolRow`，把卡片作为 ToolRow 的 `web` body 传入，因此检索成为该行默认折叠的展开卡片（与每个卡片行相同的统一展开交互）。没有自己键控行的 web 声明工具落到 `GenericToolCard` 兜底，它以同样方式经 ToolRow 渲染卡片，详情面板则以原语的完整 source 额度渲染它，并在卡片下方渲染摊平的模型可见结果内容——fetch 正文只在此处可读，因为其卡片只携带 URL 和状态。行的上限是 `CHAT_WEB_MAX_SOURCES`（8），面板为 16，与终端卡片所画的摘要面对阅读面的同一划分（[决策](../../../.agents/notes/implemented/feature/2026-07-30-web-result-card-frontend.md)）。
+声明 `web` 渲染意图的工具调用，会在两个对话渲染点上都通过 ui-primitives 的 `WebBlock` 内联渲染其 web 检索。`contract/web-card-model.ts` 是从快照的 `resultView` 推导的唯一位置，镜像终端卡片，因此两个渲染点不可能对一次 web 调用的显示产生分歧；对运行中的调用、非 web 的 result view、generic result view、本客户端版本不认识的 `card` 标签，或本客户端版本不认识 `kind` 的 web 卡片（更新的 host 发来的值，wire 上不可信其为 `search` 或 `fetch`），它返回 null，落回通用路径。键控的 `WebRow` 把一个组件注册在 `web_search` 与 `web_fetch` 两个键下，仅根据工具名判别以选取图标与标题；它组合共享的 `ToolRow`，把卡片作为 ToolRow 的 `web` body 传入，因此检索成为该行默认折叠的展开卡片（与每个卡片行相同的统一展开交互）。没有自己键控行的 web 声明工具落到 `GenericToolCard` 兜底，它以同样方式经 ToolRow 渲染卡片，详情面板渲染它，并在卡片下方渲染摊平的模型可见结果内容——fetch 正文只在此处可读，因为其卡片只携带 URL 和状态。两个渲染点显示同一份完整来源列表——工具返回、模型看到的那一份——仅受卡片自身滚动容器的高度约束，不存在行与面板的两级上限（[决策](../../../.agents/notes/implemented/feature/2026-07-30-web-result-card-frontend.md)、[来源滚动](../../../.agents/notes/implemented/feature/2026-08-03-web-search-source-scroll.md)）。

 声明 `read` 渲染意图的 `read` 调用，会在两个对话渲染点上都通过 ui-primitives 的 `ReadBlock` 内联渲染返回的文件窗口——工具投影出的带行号、语法高亮的内容。`contract/read-card-model.ts` 是从快照的 `resultView` 推导的唯一位置；read 卡片是仅结果侧的(调用在 `execute` 返回前不携带文件内容)，所以运行中的 read 只显示摘要，且对非 read 的 result view 或本客户端版本不认识的 `card` 标签返回 null，落回通用路径。键控的 `ReadRow` 组合共享的 `ToolRow`，把卡片作为 ToolRow 的 `read` body 传入，因此它是该行默认折叠的展开卡片；摘要仍是一个经 host 打开文件的路径链接。渲染点兜底行与详情面板同样感知 read。行的上限是 `CHAT_READ_MAX_LINES`（8），面板为 16（[决策](../../../.agents/notes/implemented/feature/2026-07-30-web-read-card-frontend.md)）。

--- a/packages/client/ui-conversation/src/client/chat/ToolRow.tsx
+++ b/packages/client/ui-conversation/src/client/chat/ToolRow.tsx
@@ -30,7 +30,6 @@ import type { TranslateNS } from '@deepseek-ai/dsh-client-ui-slots'
 import { CHAT_DIFF_MAX_LINES, type DiffCardModel } from '../contract/diff-card-model.ts'
 import { CHAT_READ_MAX_LINES, type ReadCardModel } from '../contract/read-card-model.ts'
 import { CHAT_SEARCH_MAX_LINES, type SearchCardModel } from '../contract/search-card-model.ts'
-import { CHAT_WEB_MAX_SOURCES } from '../contract/web-card-model.ts'
 import { terminalBlockLabels, type TerminalCardModel } from '../contract/terminal-card-model.ts'
 import type { ToolRowState, ToolRowVariant } from '../contract/tool-call-model.ts'
 import { DisclosureRow } from './DisclosureRow.tsx'
@@ -276,7 +275,7 @@ export function ToolRow({
                    </>
                  )
                  : webBody !== null
-                    ? <WebBlock {...webBody} maxSources={CHAT_WEB_MAX_SOURCES} className={css.webBody} />
+                    ? <WebBlock {...webBody} className={css.webBody} />
                    : isThink
                      ? <div className={css.thinkBody}>{body}</div>
                      : (
--- a/packages/client/ui-conversation/src/client/contract/web-card-model.ts
+++ b/packages/client/ui-conversation/src/client/contract/web-card-model.ts
@@ -15,16 +15,6 @@
 import type { WebBlockProps } from '@deepseek-ai/dsh-client-ui-primitives'
 import type { ToolCallBlock } from './tool-call-model.ts'

-/**
- * Sources the chat row's web body shows before collapsing the middle — half
- * the primitive's own default, which the details panel keeps. A chat row is a
- * summary surface inside the message flow: the flow must stay scannable across
- * many calls, while the details panel is the single-call reading surface. A
- * design constant of this UI's row geometry, not a deployment choice, so it is
- * fixed here rather than a plugin Config field.
- */
-export const CHAT_WEB_MAX_SOURCES = 8
-
 /**
 * Derive the web-card props for a tool call, or null when this call is not a
 * web card and belongs on the generic path.
--- a/packages/client/ui-conversation/src/client/skeleton/DetailsPanel.tsx
+++ b/packages/client/ui-conversation/src/client/skeleton/DetailsPanel.tsx
@@ -180,13 +180,12 @@ function OutputBody({ material, cwd, t }: { material: CallMaterial; cwd: string
    )
  }
  const web = webCardModel(material.block)
-  // Full source-list allowance here (the panel is the single-call reading
-  // surface); the chat rows cap it at CHAT_WEB_MAX_SOURCES. Below the card the
-  // panel also renders the flattened result content — the model-visible text
-  // the card does not carry verbatim (a web_fetch card shows only the URL and
-  // status, so its fetched body lives only here; a search card's answer and
-  // sources are structured, so the flattened form repeats them as the raw text
-  // the model saw).
+  // The card shows every source the tool returned (the same list the model saw),
+  // scrolling within its own capped height. Below the card the panel also renders
+  // the flattened result content — the model-visible text the card does not carry
+  // verbatim (a web_fetch card shows only the URL and status, so its fetched body
+  // lives only here; a search card's answer and sources are structured, so the
+  // flattened form repeats them as the raw text the model saw).
  if (web !== null) {
    const settled = 'kind' in material.block ? material.block : null
    const body = settled === null ? '' : resultText(settled)
--- a/packages/client/ui-conversation/tests/web-card.spec.tsx
+++ b/packages/client/ui-conversation/tests/web-card.spec.tsx
@@ -17,7 +17,7 @@ import type {
 import type { ToolResultView } from '@deepseek-ai/dsh-client-connection/client'
 import { bindSnapshotSelector } from '@deepseek-ai/dsh-client-web-react'
 import type { SelectionTarget, ToolRowOwnerProps } from '@deepseek-ai/dsh-client-ui-conversation/client'
-import { CHAT_WEB_MAX_SOURCES, webCardModel } from '../src/client/contract/web-card-model.ts'
+import { webCardModel } from '../src/client/contract/web-card-model.ts'
 import { createChatStore } from '../src/client/stores.ts'
 import { GenericToolCard } from '../src/client/chat/GenericToolCard.tsx'
 import { DetailsPanel } from '../src/client/skeleton/DetailsPanel.tsx'
@@ -135,8 +135,7 @@ describe('chat row web body', () => {
    fireEvent.click(view.container.querySelector('[data-expandable]')!)
  }

-  it('the WebRow collapses to the summary row, expanding to the search card capped tighter than the panel', () => {
-    expect(CHAT_WEB_MAX_SOURCES).toBeLessThan(16)
+  it('the WebRow collapses to the summary row, expanding to the full search card', () => {
    const view = render(<WebRow {...rowProps(settledSearch(), 'web_search')} />)
    // Collapsed: the summary row alone, no card in the DOM.
    expect(view.getByText('Search')).toBeTruthy()
--- a/packages/client/ui-primitives/README.i18n.yaml
+++ b/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: 7318acd9b9a6047b1144789bcd2655132237f6c5
-README.zh.md: e326846dc2099472bc0a81dff093ff24b614559b
+README.md: 00e9560f43c83e1edc61c185a4fc562c6c923e8b
+README.zh.md: 21226ab211106b7722139828762605cb71a4b498
--- a/packages/client/ui-primitives/README.md
+++ b/packages/client/ui-primitives/README.md
@@ -30,7 +30,7 @@ Pure React atoms (zero cordis): StateDot, ic_ds_* icons, Button/Pill/Menu/Modal/

 ## Web retrieval

-`WebBlock` renders a completed web retrieval, one component for both kinds of the `web` render intent (discriminated by `kind`). A `search` shows an optional provider answer (through `MarkdownText`) above an ordered citation list: each source is a safe external link labelled by its title, or its hostname, falling back to the raw URL when the URL does not parse or has no hostname (a `file:`/`data:` URL) so a label is never blank; its snippet and publication date render below it. Only http(s) URLs become anchors (`target`/`rel` set) — the http(s) subset of the allowlist `MarkdownText` applies to untrusted links (it also permits `mailto:`, excluded here); any other URL renders as plain text. A long list caps at `maxSources` (default 16, the TerminalBlock split arithmetic) with a head/tail collapse; the collapsed tail keeps each source's original citation number via `<li value>`, and the expand control is a marker-less `<li>` so the `<ol>` stays valid HTML. When a search legitimately returns no answer and no sources, the card shows an explicit empty-state note rather than a blank `<ol>` (the chat row does not surface the raw result content). A `fetch` shows a compact summary: the linked final URL and its HTTP status. Both mark a capped retrieval. Rationale: [the web result card note](../../../.agents/notes/implemented/feature/2026-07-30-web-result-card-frontend.md).
+`WebBlock` renders a completed web retrieval, one component for both kinds of the `web` render intent (discriminated by `kind`). A `search` shows an optional provider answer (through `MarkdownText`) above an ordered citation list: each source is a safe external link labelled by its title, or its hostname, falling back to the raw URL when the URL does not parse or has no hostname (a `file:`/`data:` URL) so a label is never blank; its snippet and publication date render below it. Only http(s) URLs become anchors (`target`/`rel` set) — the http(s) subset of the allowlist `MarkdownText` applies to untrusted links (it also permits `mailto:`, excluded here); any other URL renders as plain text. The whole list renders in one fixed-height scroll container (`max-height: 320px`, `overflow-y: auto`), so a list taller than that scrolls vertically in place instead of growing the card; `<li value>` pins each source's citation number, contiguous from 1, rather than leaving it to the `<ol>`'s implicit count. When a search legitimately returns no answer and no sources, the card shows an explicit empty-state note rather than a blank `<ol>` (the chat row does not surface the raw result content). A `fetch` shows a compact summary: the linked final URL and its HTTP status. Both mark a capped retrieval. Rationale: [the web result card note](../../../.agents/notes/implemented/feature/2026-07-30-web-result-card-frontend.md) and [the source scroll note](../../../.agents/notes/implemented/feature/2026-08-03-web-search-source-scroll.md).

 ## Model Experience

@@ -45,5 +45,5 @@ None; this package neither assembles nor sends a provider request.
 - **Glyph-level icons are redrawn approximations** — the fish logo (and the sparkle held by ui-conversation) come from font glyphs whose vector geometry is not exportable from the local design data; hand-authored recreations stand in until an exact export path exists.
 - **Pill and Input have no design source** — both atoms are self-defined; the sidebar search field and view-tab strip that resemble them are consumer-owned compositions, not these atoms.
 - **StateDot `Active` variant is a hidden placeholder in the design** — not implemented; the four shipped states (done/warning/ongoing/error) are the complete P-I surface.
- **User-facing copy localizes through label props, defaulting to the original Chinese literals** — the atoms are zero-cordis and cannot reach `ctx.locale`, so `HoverCard` (`copyLabel`/`copiedLabel`), `TerminalBlock` (`labels`), `JsonTree` (`labels`), `CodeBlock` (`copyLabel`/`copiedLabel`), `MarkdownText` (`codeLabels`), `JsonBlock` (`truncatedLabel`), `ConnectionBanner` (`label`), and `Modal` (`closeLabel`) take their copy as optional props with the previous hardcoded strings as defaults. Localized plugins pass dictionary-driven labels from their own `t` seat; a consumer that passes nothing renders exactly the pre-localization output. `WebBlock` does not yet follow this pattern: its source expand/collapse controls, source-list and fetch truncation notes, and empty-search note stay inline Chinese, pending the same label-prop treatment.
+- **User-facing copy localizes through label props, defaulting to the original Chinese literals** — the atoms are zero-cordis and cannot reach `ctx.locale`, so `HoverCard` (`copyLabel`/`copiedLabel`), `TerminalBlock` (`labels`), `JsonTree` (`labels`), `CodeBlock` (`copyLabel`/`copiedLabel`), `MarkdownText` (`codeLabels`), `JsonBlock` (`truncatedLabel`), `ConnectionBanner` (`label`), and `Modal` (`closeLabel`) take their copy as optional props with the previous hardcoded strings as defaults. Localized plugins pass dictionary-driven labels from their own `t` seat; a consumer that passes nothing renders exactly the pre-localization output. `WebBlock` does not yet follow this pattern: its source-list and fetch truncation notes and its empty-search note stay inline Chinese, pending the same label-prop treatment.
 - **`TerminalBlock` is not a terminal emulator** — it renders settled or still-running command output, not an interactive session: SGR color and attributes are honored, and so are the in-line cursor movements a progress line uses — carriage return, backspace, erase-in-line, tab stops and character width. Absolute cursor positioning, screen clearing, and alternate-screen sequences are stripped. Basic-16 magenta and cyan have no token equivalent and stay literal rgb.
--- a/packages/client/ui-primitives/README.zh.md
+++ b/packages/client/ui-primitives/README.zh.md
@@ -30,7 +30,7 @@

 ## Web 检索

-`WebBlock` 渲染一次已完成的 web 检索，用一个组件绘制 `web` 渲染意图的两种 kind（由 `kind` 判别）。`search` 在有序引用列表上方显示可选的 provider answer（通过 `MarkdownText`）：每个 source 是一个安全外链，以其标题为标签，或以其主机名为标签，当 URL 无法解析或没有主机名（`file:`/`data:` URL）时回退到原始 URL，因此标签绝不为空；其下渲染 snippet 与发布日期。只有 http(s) URL 会成为锚点（设置 `target`/`rel`）——这是 `MarkdownText` 对不受信任链接所用 allowlist 的 http(s) 子集（该 allowlist 还允许 `mailto:`，此处排除）；任何其他 URL 渲染为纯文本。长列表在 `maxSources`（默认 16，即 TerminalBlock 的切分算术）处折叠为头部/尾部；折叠的尾部通过 `<li value>` 保留每个 source 原始的引用编号，展开控件是无 marker 的 `<li>`，使 `<ol>` 保持为合法 HTML。当一次 search 合法地返回无 answer 且无 source 时，卡片显示一个明确的空状态提示，而不是空的 `<ol>`（chat 行不呈现原始 result content）。`fetch` 显示一个紧凑摘要：带链接的最终 URL 及其 HTTP 状态。两者都会标记一次被截断的检索。原理：[Web result 卡片笔记](../../../.agents/notes/implemented/feature/2026-07-30-web-result-card-frontend.md)。
+`WebBlock` 渲染一次已完成的 web 检索，用一个组件绘制 `web` 渲染意图的两种 kind（由 `kind` 判别）。`search` 在有序引用列表上方显示可选的 provider answer（通过 `MarkdownText`）：每个 source 是一个安全外链，以其标题为标签，或以其主机名为标签，当 URL 无法解析或没有主机名（`file:`/`data:` URL）时回退到原始 URL，因此标签绝不为空；其下渲染 snippet 与发布日期。只有 http(s) URL 会成为锚点（设置 `target`/`rel`）——这是 `MarkdownText` 对不受信任链接所用 allowlist 的 http(s) 子集（该 allowlist 还允许 `mailto:`，此处排除）；任何其他 URL 渲染为纯文本。整份列表渲染在一个定高滚动容器里（`max-height: 320px`、`overflow-y: auto`），因此超出该高度的列表在原地纵向滚动，而不是把卡片撑高；`<li value>` 固定每个 source 的引用编号，从 1 起连续，而不依赖 `<ol>` 的隐式计数。当一次 search 合法地返回无 answer 且无 source 时，卡片显示一个明确的空状态提示，而不是空的 `<ol>`（chat 行不呈现原始 result content）。`fetch` 显示一个紧凑摘要：带链接的最终 URL 及其 HTTP 状态。两者都会标记一次被截断的检索。原理：[Web result 卡片笔记](../../../.agents/notes/implemented/feature/2026-07-30-web-result-card-frontend.md)与[来源滚动笔记](../../../.agents/notes/implemented/feature/2026-08-03-web-search-source-scroll.md)。

 ## 模型体验

@@ -45,5 +45,5 @@
 - **字形级图标是重新绘制的近似版本**：鱼形标志（以及 ui-conversation 持有的闪光图标）来自字体字形，而本地设计数据无法导出其矢量几何；在获得精确导出路径前，使用手工重建版本代替。
 - **Pill 与 Input 没有设计来源**：两个原子组件均自行定义；与其相似的侧边栏搜索字段和视图标签条由消费方组合，不是这些原子组件。
 - **StateDot 的 `Active` 变体是设计中的隐藏占位符**：尚未实现；已交付的四种状态（done/warning/ongoing/error）构成完整的 P-I 表层。
- **面向用户的文案经 label props 本地化，默认值为原中文字面量**：这些原子组件是 zero-cordis 的，拿不到 `ctx.locale`，因此 `HoverCard`（`copyLabel`/`copiedLabel`）、`TerminalBlock`（`labels`）、`JsonTree`（`labels`）、`CodeBlock`（`copyLabel`/`copiedLabel`）、`MarkdownText`（`codeLabels`）、`JsonBlock`（`truncatedLabel`）、`ConnectionBanner`（`label`）和 `Modal`（`closeLabel`）都把文案作为可选 props 接收，默认值即此前的硬编码字符串。已本地化的插件用自己的 `t` 席位传入字典驱动的 label；什么都不传的消费者渲染与本地化之前逐字节一致。`WebBlock` 尚未跟进这一模式：它的来源展开/收起控件、来源列表与 fetch 截断提示、以及空搜索提示仍是内联中文，待同样的 label-prop 处理。
+- **面向用户的文案经 label props 本地化，默认值为原中文字面量**：这些原子组件是 zero-cordis 的，拿不到 `ctx.locale`，因此 `HoverCard`（`copyLabel`/`copiedLabel`）、`TerminalBlock`（`labels`）、`JsonTree`（`labels`）、`CodeBlock`（`copyLabel`/`copiedLabel`）、`MarkdownText`（`codeLabels`）、`JsonBlock`（`truncatedLabel`）、`ConnectionBanner`（`label`）和 `Modal`（`closeLabel`）都把文案作为可选 props 接收，默认值即此前的硬编码字符串。已本地化的插件用自己的 `t` 席位传入字典驱动的 label；什么都不传的消费者渲染与本地化之前逐字节一致。`WebBlock` 尚未跟进这一模式：它的来源列表与 fetch 截断提示、以及空搜索提示仍是内联中文，待同样的 label-prop 处理。
 - **`TerminalBlock` 不是终端模拟器**：它渲染已结束或仍在运行的命令输出，而不是交互式会话：SGR 颜色与属性会被遵循，进度行所用的行内光标移动同样被遵循——回车、退格、行内擦除、制表位与字符宽度。绝对光标定位、清屏与备用屏幕序列会被剥离。基础 16 色中的洋红与青色没有对应 token，保持字面 rgb。
--- a/packages/client/ui-primitives/src/WebBlock.module.css
+++ b/packages/client/ui-primitives/src/WebBlock.module.css
@@ -1,7 +1,8 @@
 /* Geometry mirrors CodeBlock/TerminalBlock (12px radius, code-block surface,
   16px vertical margin) so a web card, a terminal card, and a fenced code block
-   read as one family. A source list is prose, not aligned output, so it wraps
-   normally rather than scrolling horizontally like a terminal card's output. */
+   read as one family. A source list is prose, not aligned output, so each row
+   wraps horizontally rather than scrolling sideways like a terminal card; the
+   list as a whole scrolls vertically within a capped height (see .sources). */

 .block {
  --dsl-web-radius: 12px;
@@ -27,13 +28,29 @@
  margin-bottom: 0;
 }

-/* The citation list: ordered so each source reads as a numbered reference. */
+/* The citation list: ordered so each source reads as a numbered reference. The
+   whole list — the sources the tool returned, matching what the model saw —
+   renders here; a max-height caps the card so a long list scrolls in place
+   rather than growing the card unbounded. The height is a design constant of the
+   card's geometry, not a deployment choice, so it lives here rather than a plugin
+   config field.
+
+   `overflow-y` makes this a scroll container, which also clips inline-start
+   overflow: a marker wider than `padding-left` loses its leading digits with no
+   way to scroll them back. Markers are right-aligned to the content edge, so the
+   padding must fit the widest one the list can produce. `searchMaxResults` is an
+   unbounded positive integer, so the padding is sized in `em` — against this
+   element's own font, the one a marker inherits — to hold a three-digit marker
+   (`999. ` measures 2.35em in the app font stack) plus the gap the one-digit
+   case already had. */
 .sources {
  margin: 0;
-  padding-left: 20px;
+  padding-left: 2.5em;
  display: flex;
  flex-direction: column;
  gap: 10px;
+  max-height: 320px;
+  overflow-y: auto;
 }

 .source {
@@ -65,26 +82,6 @@
  font: var(--dsw-font-xs-13);
 }

-.expandItem {
-  list-style: none;
-}
-
-.expand {
-  display: block;
-  width: 100%;
-  padding: 0;
-  border: none;
-  background-color: transparent;
-  color: var(--dsw-alias-label-tertiary);
-  cursor: pointer;
-  font: inherit;
-  text-align: left;
-}
-
-.expand:hover {
-  color: var(--dsw-alias-label-secondary);
-}
-
 .truncated {
  margin-top: 8px;
  color: var(--dsw-alias-label-tertiary);
--- a/packages/client/ui-primitives/src/WebBlock.tsx
+++ b/packages/client/ui-primitives/src/WebBlock.tsx
@@ -9,22 +9,20 @@
 // allowlist MarkdownText applies to untrusted assistant-authored links (it also
 // permits mailto, excluded here); an unparseable or non-http URL renders as
 // plain text. Geometry, radius, and fonts mirror CodeBlock/TerminalBlock so a
-// web card reads as one family with them; a long source list caps at maxSources
-// with a head/tail collapse using the same arithmetic as TerminalBlock's output
-// cap.
+// web card reads as one family with them; the whole source list renders inside a
+// fixed-height scroll container (its `.sources` max-height), so a long list
+// scrolls in place rather than growing the card — and that container's
+// `padding-left` must stay wide enough for the widest `<li>` marker, since a
+// scroll container clips inline-start overflow irrecoverably. The card draws every source the
+// view carries: the tool already cut the list to its source cap, and `truncated`
+// reports that cut. A content-only transform downstream of the tool — spill-policy
+// replacing an oversized result's text while leaving its presentationMeta whole —
+// can still narrow what the model reads below this list.

-import { useCallback, useState } from 'react'
 import clsx from 'clsx'
 import { MarkdownText } from './markdown/MarkdownText.tsx'
 import css from './WebBlock.module.css'

-/**
- * Sources shown before the height cap collapses the middle of a citation list.
- * Matches TerminalBlock's default output budget so both cards cut a long body
- * at the same place; the chat row narrows it through the maxSources prop.
- */
-export const DEFAULT_WEB_MAX_SOURCES = 16
-
 /**
 * One citeable source drawn in a search card: the projection of the contract's
 * `WebSource`, with the optional fields kept optional so a provider that
@@ -50,8 +48,6 @@ export interface WebSearchBlockProps {
  sources: WebSourceView[]
  /** True when the tool cut the source list to its result cap. */
  truncated: boolean
-  /** Sources shown before the middle collapses (default {@link DEFAULT_WEB_MAX_SOURCES}). */
-  maxSources?: number | undefined
  /** Extra class merged onto the wrapper (callers position; this component draws). */
  className?: string | undefined
 }
@@ -65,13 +61,6 @@ export interface WebFetchBlockProps {
  statusCode: number
  /** True when the provider or the output cap cut the fetched content. */
  truncated: boolean
-  /**
-   * Accepted and ignored, so both card kinds take one uniform prop set (a fetch
-   * card has no source list to cap) — the same way TerminalBlock accepts one
-   * `maxLines` across its arms. Lets a render site spread `maxSources` onto
-   * either kind without a per-kind conditional.
-   */
-  maxSources?: number | undefined
  /** Extra class merged onto the wrapper (callers position; this component draws). */
  className?: string | undefined
 }
@@ -137,9 +126,9 @@ function SafeLink({ url, label, className }: { url: string; label: string; class

 /**
 * One source row in a search card: the safe link plus its snippet and date. The
- * `<li value>` pins the source's original 1-based position, so a collapsed list
- * whose tail is drawn after the head still numbers each source by its real
- * citation index rather than by its position in the visible subset.
+ * `<li value>` pins the source's 1-based citation index explicitly rather than
+ * relying on the `<ol>`'s implicit numbering, so a row reads by its real index
+ * even inside the scroll container.
 * @param props.source - the source to render.
 * @param props.ordinal - the source's 1-based position in the full list.
 * @returns the source list item.
@@ -159,21 +148,12 @@ function SourceItem({ source, ordinal }: { source: WebSourceView; ordinal: numbe
 }

 /**
- * The search card body: the answer over the capped source list.
+ * The search card body: the answer over the full source list, which scrolls in
+ * place once it exceeds the `.sources` container height.
 * @param props - see {@link WebSearchBlockProps}.
 * @returns the search card element.
 */
-function WebSearchBlock({ answer, sources, truncated, maxSources = DEFAULT_WEB_MAX_SOURCES, className }: WebSearchBlockProps) {
-  const [expanded, setExpanded] = useState(false)
-  const onToggle = useCallback(() => { setExpanded(value => !value) }, [])
-  const hidden = sources.length - maxSources
-  const capped = hidden > 0 && !expanded
-  // Same split arithmetic as TerminalBlock's output cap, so a long body's head
-  // and tail slices agree between the two cards.
-  const headCount = Math.ceil(maxSources / 2)
-  const tailCount = maxSources - headCount
-  const head = capped ? sources.slice(0, headCount) : sources
-  const tail = capped ? sources.slice(sources.length - tailCount) : []
+function WebSearchBlock({ answer, sources, truncated, className }: WebSearchBlockProps) {
  // A provider may legitimately return no answer and no sources; the chat WebRow
  // does not show the raw result content, so without this the user would see an
  // empty card. Mirror the backend's `No results found.` render text.
@@ -187,27 +167,7 @@ function WebSearchBlock({ answer, sources, truncated, maxSources = DEFAULT_WEB_M
        <div className={css.empty}>未找到结果</div>
      ) : (
        <ol className={css.sources}>
-          {head.map((source, index) => <SourceItem key={index} source={source} ordinal={index + 1} />)}
-          {hidden > 0 && (
-            <li className={css.expandItem}>
-              <button
-                type="button"
-                className={css.expand}
-                aria-expanded={expanded}
-                aria-label={expanded ? '收起来源' : `展开其余 ${hidden} 条来源`}
-                onClick={onToggle}
-              >
-                {expanded ? '收起' : `… 其余 ${hidden} 条来源`}
-              </button>
-            </li>
-          )}
-          {tail.map((source, index) => (
-            <SourceItem
-              key={sources.length - tailCount + index}
-              source={source}
-              ordinal={sources.length - tailCount + index + 1}
-            />
-          ))}
+          {sources.map((source, index) => <SourceItem key={index} source={source} ordinal={index + 1} />)}
        </ol>
      )}
      {truncated && <div className={css.truncated}>来源列表已截断</div>}
--- a/packages/client/ui-primitives/src/index.ts
+++ b/packages/client/ui-primitives/src/index.ts
@@ -32,7 +32,7 @@ export { SearchBlock, DEFAULT_SEARCH_MAX_LINES } from './SearchBlock.tsx'
 export type {
  SearchBlockProps, SearchMatchesBlockProps, SearchPathsBlockProps, SearchFileGroup, SearchBlockLineMatch,
 } from './SearchBlock.tsx'
-export { WebBlock, DEFAULT_WEB_MAX_SOURCES } from './WebBlock.tsx'
+export { WebBlock } from './WebBlock.tsx'
 export type { WebBlockProps, WebSearchBlockProps, WebFetchBlockProps, WebSourceView } from './WebBlock.tsx'
 export { CodeBlock } from './markdown/CodeBlock.tsx'
 export type { CodeBlockProps } from './markdown/CodeBlock.tsx'
--- a/packages/client/ui-primitives/tests/web-block.spec.tsx
+++ b/packages/client/ui-primitives/tests/web-block.spec.tsx
@@ -1,19 +1,19 @@
 // @vitest-environment jsdom
 // WebBlock: both kinds of the web card. The search card's answer, its citation
 // list with the title-or-hostname label fallback and optional snippet/date, the
-// source-list height cap and its expand control, and the truncated indicator;
-// the fetch card's linked URL, status, and truncation. Safe-link attributes on
-// both kinds: an http(s) URL becomes an external anchor (target/rel), any other
-// URL renders as plain text with no href.
+// full source list under one <ol>, and the truncated indicator; the fetch
+// card's linked URL, status, and truncation. Safe-link
+// attributes on both kinds: an http(s) URL becomes an external anchor
+// (target/rel), any other URL renders as plain text with no href.

 import { afterEach, describe, expect, it } from 'vitest'
-import { cleanup, fireEvent, render } from '@testing-library/react'
-import { DEFAULT_WEB_MAX_SOURCES, WebBlock } from '../src/index.ts'
+import { cleanup, render } from '@testing-library/react'
+import { WebBlock } from '../src/index.ts'
 import type { WebSourceView } from '../src/index.ts'

 afterEach(cleanup)

-/** `count` sources with sequential hostnames, so the cap slices read distinctly. */
+/** `count` sources with sequential hostnames, so each row reads distinctly. */
 function sources(count: number): WebSourceView[] {
  return Array.from({ length: count }, (_value, index) => ({
    url: `https://site-${index}.example.com/page`,
@@ -123,58 +123,25 @@ describe('WebBlock search card', () => {
    expect(off.queryByText('来源列表已截断')).toBeNull()
  })

-  it('renders every source and no expand control under the cap', () => {
-    const view = render(<WebBlock kind="search" sources={sources(4)} truncated={false} maxSources={4} />)
-    expect(view.container.querySelectorAll('[class^="_source_"]')).toHaveLength(4)
+  it('renders every source in one <ol> with no expand control', () => {
+    // The card shows the whole list the tool returned, with no head/tail
+    // collapse and no expand button. jsdom does not resolve the CSS Modules
+    // layout, so the scroll geometry the `.sources` max-height produces is
+    // pinned by the assembled browser case in apps/web/tests/web-search-round.e2e.ts,
+    // not here.
+    const view = render(<WebBlock kind="search" sources={sources(30)} truncated={false} />)
+    expect(view.container.querySelectorAll('li[class^="_source_"]')).toHaveLength(30)
    expect(view.container.querySelector('[aria-expanded]')).toBeNull()
-  })
-
-  it('slices head and tail over the cap and expands on click', () => {
-    const view = render(<WebBlock kind="search" sources={sources(10)} truncated={false} maxSources={4} />)
-    // maxSources 4: head = ceil(4/2) = 2, tail = 4 - 2 = 2, 6 hidden.
-    expect([...view.container.querySelectorAll('[class^="_sourceLink_"]')].map(n => n.textContent))
-      .toEqual(['Source 0', 'Source 1', 'Source 8', 'Source 9'])
-    const toggle = view.getByRole('button', { name: '展开其余 6 条来源' })
-    expect(toggle.getAttribute('aria-expanded')).toBe('false')
-    expect(toggle.textContent).toBe('… 其余 6 条来源')
-
-    fireEvent.click(toggle)
-    expect(view.container.querySelectorAll('[class^="_source_"]')).toHaveLength(10)
-    const collapse = view.getByRole('button', { name: '收起来源' })
-    expect(collapse.getAttribute('aria-expanded')).toBe('true')
-    expect(collapse.textContent).toBe('收起')
-
-    fireEvent.click(collapse)
-    expect(view.container.querySelectorAll('[class^="_source_"]')).toHaveLength(4)
-  })
-
-  it('numbers a collapsed tail by each source original position, not its visible slot', () => {
-    // maxSources 4 over 10 sources: the tail is sources 8 and 9, which must read
-    // as citations 9 and 10 (via <li value>), not renumbered 3 and 4.
-    const view = render(<WebBlock kind="search" sources={sources(10)} truncated={false} maxSources={4} />)
-    const items = [...view.container.querySelectorAll('li[class^="_source_"]')]
-    expect(items.map(li => li.getAttribute('value'))).toEqual(['1', '2', '9', '10'])
-  })
-
-  it('keeps the expander out of the ordered-list numbering', () => {
-    // The expander is a marker-less <li>, so it is valid inside <ol> and does not
-    // consume a citation number between the head and tail sources.
-    const view = render(<WebBlock kind="search" sources={sources(10)} truncated={false} maxSources={4} />)
+    expect(view.container.querySelector('button')).toBeNull()
+    // Every direct child of the <ol> is a source <li> (no marker-less expander).
    const ol = view.container.querySelector('ol')!
-    // Every direct child is an <li> (no bare <button> child — invalid HTML).
    expect([...ol.children].every(child => child.tagName === 'LI')).toBe(true)
  })

-  it('renders the head slice alone when the cap leaves no tail', () => {
-    const view = render(<WebBlock kind="search" sources={sources(5)} truncated={false} maxSources={1} />)
-    expect([...view.container.querySelectorAll('[class^="_sourceLink_"]')].map(n => n.textContent)).toEqual(['Source 0'])
-    expect(view.getByRole('button', { name: '展开其余 4 条来源' })).toBeTruthy()
-  })
-
-  it('caps at the documented default when maxSources is absent', () => {
-    const view = render(<WebBlock kind="search" sources={sources(DEFAULT_WEB_MAX_SOURCES + 1)} truncated={false} />)
-    expect(view.container.querySelectorAll('[class^="_source_"]')).toHaveLength(DEFAULT_WEB_MAX_SOURCES)
-    expect(view.getByRole('button', { name: '展开其余 1 条来源' })).toBeTruthy()
+  it('numbers every source by its 1-based citation index via <li value>', () => {
+    const view = render(<WebBlock kind="search" sources={sources(4)} truncated={false} />)
+    const items = [...view.container.querySelectorAll('li[class^="_source_"]')]
+    expect(items.map(li => li.getAttribute('value'))).toEqual(['1', '2', '3', '4'])
  })
 })

--- a/packages/session-persistence/session-persistence-jsonl/src/index.ts
+++ b/packages/session-persistence/session-persistence-jsonl/src/index.ts
@@ -22,7 +22,7 @@ import {
  encodeSegment, eventLines, logPath, logSuffix, parseHeaderMeta, projectDir, scanLog, sessionDir, toHeaderLine,
  type JsonlCompression,
 } from './format.ts'
-import { compressZstdFrame, decompressZstdFrame, scanZstdFrames } from './zstd.ts'
+import { compressZstdFrame, decompressZstdFrame, decompressZstdPrefix, scanZstdFrames } from './zstd.ts'
 import { ensureDurableDirectoryWin32, publishNewFileWin32 } from './win32.ts'

 export type { JsonlCompression } from './format.ts'
@@ -232,7 +232,7 @@ export class SessionPersistenceJsonl extends SessionPersistence implements Persi
    let recoveredPlaintext: Buffer = Buffer.alloc(0)
    try {
      signal?.throwIfAborted()
-      recoveredPlaintext = await decompressZstdFrame(buffer.subarray(tornStart))
+      recoveredPlaintext = await decompressZstdPrefix(buffer.subarray(tornStart))
    } catch {
      /* v8 ignore next -- decoder failure plus concurrent abort is timing-dependent */
      if (signal?.aborted) signal.throwIfAborted()
--- a/packages/session-persistence/session-persistence-jsonl/src/zstd.ts
+++ b/packages/session-persistence/session-persistence-jsonl/src/zstd.ts
@@ -14,6 +14,9 @@ const zstdDecompressAsync = promisify(zstdDecompress)
 const CHECKSUM_OPTIONS: ZstdOptions = {
  params: { [constants.ZSTD_c_checksumFlag]: 1 },
 }
+const INCOMPLETE_FRAME_OPTIONS: ZstdOptions = {
+  finishFlush: constants.ZSTD_e_flush,
+}

 /** Byte range occupied by one structurally complete Zstandard frame. */
 export interface ZstdFrameRange {
@@ -106,11 +109,21 @@ export async function compressZstdFrame(input: Buffer | string): Promise<Buffer>
 }

 /**
- * Decompress one complete frame or the available prefix of a torn final frame.
- * Complete-frame checksums are validated by Node's decoder.
- * @param input - bytes beginning at a Zstandard frame boundary.
- * @returns plaintext produced from the available input.
+ * Decompress one complete frame and validate its checksum.
+ * @param input - one structurally complete Zstandard frame.
+ * @returns the frame plaintext.
 */
 export async function decompressZstdFrame(input: Buffer): Promise<Buffer> {
  return zstdDecompressAsync(input)
 }
+
+/**
+ * Recover available plaintext from a structurally incomplete final frame.
+ * `ZSTD_e_flush` deliberately suppresses final-frame and checksum completion;
+ * callers must establish the torn frame boundary before using this helper.
+ * @param input - available bytes from a known incomplete Zstandard frame.
+ * @returns plaintext produced from the available input.
+ */
+export async function decompressZstdPrefix(input: Buffer): Promise<Buffer> {
+  return zstdDecompressAsync(input, INCOMPLETE_FRAME_OPTIONS)
+}
--- a/packages/session-persistence/session-persistence-jsonl/tests/zstd.compat.spec.ts
+++ b/packages/session-persistence/session-persistence-jsonl/tests/zstd.compat.spec.ts
@@ -1,5 +1,5 @@
 import { describe, expect, it } from 'vitest'
-import { compressZstdFrame, decompressZstdFrame, scanZstdFrames } from '../src/zstd.ts'
+import { compressZstdFrame, decompressZstdFrame, decompressZstdPrefix, scanZstdFrames } from '../src/zstd.ts'

 describe('JSONL Zstandard compatibility', () => {
  it('round-trips concatenated checksummed frames through the built-in Node API', async () => {
@@ -19,6 +19,6 @@ describe('JSONL Zstandard compatibility', () => {
    const eventFrame = encoded.subarray(frames[1]!.start, frames[1]!.end)
    const missingChecksumByte = eventFrame.subarray(0, -1)
    expect(scanZstdFrames(missingChecksumByte)).toEqual({ frames: [], tornStart: 0 })
-    expect((await decompressZstdFrame(missingChecksumByte)).toString()).toContain('"type":"turn/start"')
+    expect((await decompressZstdPrefix(missingChecksumByte)).toString()).toContain('"type":"turn/start"')
  })
 })
--- a/packages/session-persistence/session-persistence-jsonl/tests/zstd.spec.ts
+++ b/packages/session-persistence/session-persistence-jsonl/tests/zstd.spec.ts
@@ -8,7 +8,7 @@ import SessionStore, { SessionId } from '@deepseek-ai/dsh-session'
 import type { SessionEvent } from '@deepseek-ai/dsh-session'
 import SessionPersistenceJsonl from '@deepseek-ai/dsh-session-persistence-jsonl'
 import { logPath, scanLog, sessionDir, toHeaderLine, type JsonlCompression } from '../src/format.ts'
-import { compressZstdFrame, decompressZstdFrame, scanZstdFrames } from '../src/zstd.ts'
+import { compressZstdFrame, decompressZstdFrame, decompressZstdPrefix, scanZstdFrames } from '../src/zstd.ts'
 import { runPersistenceContract, meta, oneTurnLog } from '../../session-persistence/tests/contract.ts'
 import { runCoordinatorContract, type CoordinatorFixture } from '../../session-persistence/tests/coordinator-contract.ts'

@@ -69,7 +69,7 @@ async function tornFrame(
    const candidate = frame.subarray(0, end)
    if (scanZstdFrames(candidate).tornStart !== 0) continue
    try {
-      const decoded = (await decompressZstdFrame(candidate)).toString('utf8')
+      const decoded = (await decompressZstdPrefix(candidate)).toString('utf8')
      if (accepts(decoded)) return candidate
    } catch {
      // Some early cuts precede the first decodable block; keep searching for
--- a/packages/support/acp-snapshot/src/harness.ts
+++ b/packages/support/acp-snapshot/src/harness.ts
@@ -43,16 +43,22 @@ const WAIT_POLL_INTERVAL_MS = 10
 * reference, since a committed file cannot know the id in advance.
 *
 * `promptAndCancel` starts a prompt without awaiting completion, waits for a
- * readiness condition, then cancels and awaits completion. `waitForFile`
- * observes a cwd-relative marker; the default observes the durable turn start.
+ * readiness condition, then cancels and awaits completion. Its optional
+ * `waitForFile` observes a cwd-relative marker; otherwise it waits for the
+ * durable turn start. The standalone `waitForFile` holds the next script step
+ * behind the same marker.
 * `promptAndWaitForAgentMessage` arms an exact text-chunk waiter before sending
 * the prompt, then keeps the application live until that later update arrives.
 * `waitForTurnStart` waits for an open durable turn, optionally at or beyond a
 * specified turn number. `waitForTurnEnd` holds the subprocess open until the
 * selected session's latest complete raw-JSONL turn boundary is `turn/end`.
+ * `waitForSubagentTurnEnd` waits until one background child has persisted a
+ * closed model-work turn after its own descriptor; child progress has no ACP
+ * update to wait on.
 * `waitForTitleAfterTurnEnd` additionally waits for a later durable title.
- * `waitForSubagentTurnEnd` applies the same work-turn boundary to one
- * background child, whose progress has no ACP update to wait on.
+ * `waitForEventAfterTurnEnd` waits until a complete record of the given event
+ * type follows the latest closed turn — for scenarios whose asserted state
+ * (e.g. a goal pause) is appended only after cancellation reaches idle.
 * A standalone `cancel` may also wait for a cwd-relative readiness marker.
 * All wait timeouts default to 10s.
 */
@@ -73,6 +79,7 @@ export type InputStep =
  | { op: 'waitForTurnEnd'; timeoutMs?: number }
  | { op: 'waitForSubagentTurnEnd'; child?: number; timeoutMs?: number }
  | { op: 'waitForTitleAfterTurnEnd'; timeoutMs?: number }
+  | { op: 'waitForEventAfterTurnEnd'; type: string; timeoutMs?: number }
  | { op: 'cancel'; waitForFile?: { path: string; timeoutMs?: number } }

 /** A scenario's `input.json`: an ordered list of input steps. */
@@ -296,6 +303,7 @@ export async function runScenario(input: InputScript, opts: RunOptions): Promise
        (id, timeoutMs) => waitForPersistedTurnEnd(sessionsRoot, id, timeoutMs),
        (child, timeoutMs) => waitForPersistedChildTurnEnd(sessionsRoot, child, timeoutMs),
        (id, timeoutMs) => waitForPersistedTitleAfterTurnEnd(sessionsRoot, id, timeoutMs),
+        (id, type, timeoutMs) => waitForPersistedEventAfterTurnEnd(sessionsRoot, id, type, timeoutMs),
      )
      // A permission exchange happens while a step's request is in flight, so
      // by the time the step settles any script bug it exposed is captured —
@@ -371,6 +379,7 @@ async function runStep(
  waitForTurnEnd: (sessionId: string, timeoutMs?: number) => Promise<void>,
  waitForChildTurnEnd: (child: number, timeoutMs?: number) => Promise<void>,
  waitForTitleAfterTurnEnd: (sessionId: string, timeoutMs?: number) => Promise<void>,
+  waitForEventAfterTurnEnd: (sessionId: string, type: string, timeoutMs?: number) => Promise<void>,
 ): Promise<void> {
  switch (step.op) {
    case 'initialize':
@@ -460,6 +469,12 @@ async function runStep(
      await waitForTitleAfterTurnEnd(sessionId, step.timeoutMs)
      return
    }
+    case 'waitForEventAfterTurnEnd': {
+      const sessionId = getSessionId()
+      if (sessionId === undefined) throw new Error('snapshot-harness: waitForEventAfterTurnEnd before newSession')
+      await waitForEventAfterTurnEnd(sessionId, step.type, step.timeoutMs)
+      return
+    }
    case 'waitForTurnStart': {
      const sessionId = getSessionId()
      if (sessionId === undefined) throw new Error('snapshot-harness: waitForTurnStart before newSession')
@@ -576,6 +591,21 @@ async function waitForPersistedTitleAfterTurnEnd(
  }, { interval: WAIT_POLL_INTERVAL_MS, timeout: timeoutMs })
 }

+/** Wait until a complete record of `type` follows the latest closed turn. */
+async function waitForPersistedEventAfterTurnEnd(
+  root: string,
+  sessionId: string,
+  type: string,
+  timeoutMs = DEFAULT_WAIT_TIMEOUT_MS,
+): Promise<void> {
+  await vi.waitFor(async () => {
+    const log = (await harvestSessionLogs(root)).find(candidate => candidate.id === sessionId)
+    if (log === undefined || !latestEventFollowsTurnEnd(log.content, type)) {
+      throw new Error(`snapshot-harness: session "${sessionId}" did not persist ${type} after turn/end within ${timeoutMs}ms`)
+    }
+  }, { interval: WAIT_POLL_INTERVAL_MS, timeout: timeoutMs })
+}
+
 /** Wait for a cwd-relative marker proving an external action reached readiness. */
 async function waitForWorkspaceFile(
  cwd: string,
@@ -604,6 +634,13 @@ function latestTitleFollowsTurnEnd(content: string): boolean {
  return turnEnd >= 0 && complete.lastIndexOf('\n{"type":"session/title",') > turnEnd
 }

+/** Return whether a complete record of `type` occurs after the last complete turn end. */
+function latestEventFollowsTurnEnd(content: string, type: string): boolean {
+  const complete = content.slice(0, content.lastIndexOf('\n') + 1)
+  const turnEnd = complete.lastIndexOf('\n{"type":"turn/end",')
+  return turnEnd >= 0 && complete.lastIndexOf(`\n{"type":"${type}",`) > turnEnd
+}
+
 /** Return the latest open turn number, validating the persisted boundary record. */
 function latestOpenTurn(content: string): number | undefined {
  const complete = content.slice(0, content.lastIndexOf('\n') + 1)
--- a/packages/support/acp-snapshot/tests/harness.spec.ts
+++ b/packages/support/acp-snapshot/tests/harness.spec.ts
@@ -844,6 +844,55 @@ describe('runScenario', () => {
    )).rejects.toThrow(/did not persist session\/title after turn\/end within 20ms/)
  })

+  it('waitForEventAfterTurnEnd holds the app for a typed post-boundary record and times out otherwise', { timeout: 20_000 }, async () => {
+    const late = await scenario({
+      prompt: 'hang-until-cancel',
+      persistLogsOnCancel: true,
+      logs: [{
+        file: 'project/main/session.jsonl',
+        lines: [
+          { type: 'session', version: 0, id: '{{SID}}', createdAt: 1, delegationDepth: 0 },
+          { type: 'turn/end', seq: 1, time: 2, data: { turn: 1, reason: { kind: 'aborted' } } },
+          { type: 'user/message', seq: 2, time: 3, data: { content: [{ type: 'text', text: 'late goal state' }], source: { kind: 'user' } } },
+        ],
+      }],
+    })
+    const result = await runScenario(
+      {
+        steps: [
+          ...boot,
+          { op: 'promptAndCancel', text: 'hang' },
+          { op: 'waitForEventAfterTurnEnd', type: 'user/message' },
+        ],
+      },
+      { agent: AGENT, mode: 'replay', fixtureFile: late.fixtureFile },
+    )
+    expect(result.sessionLogs[0]?.content).toMatch(/"turn\/end"[\s\S]*"user\/message"/)
+
+    const early = await scenario({
+      prompt: 'hang-until-cancel',
+      persistLogsOnCancel: true,
+      logs: [{
+        file: 'project/main/session.jsonl',
+        lines: [
+          { type: 'session', version: 0, id: '{{SID}}', createdAt: 1, delegationDepth: 0 },
+          { type: 'user/message', seq: 1, time: 1, data: { content: [{ type: 'text', text: 'early' }], source: { kind: 'user' } } },
+          { type: 'turn/end', seq: 2, time: 2, data: { turn: 1, reason: { kind: 'aborted' } } },
+        ],
+      }],
+    })
+    await expect(runScenario(
+      {
+        steps: [
+          ...boot,
+          { op: 'promptAndCancel', text: 'hang' },
+          { op: 'waitForEventAfterTurnEnd', type: 'user/message', timeoutMs: 20 },
+        ],
+      },
+      { agent: AGENT, mode: 'replay', fixtureFile: early.fixtureFile },
+    )).rejects.toThrow(/did not persist user\/message after turn\/end within 20ms/)
+  })
+
  it('promptExpectError swallows a model-error response as the expected outcome', { timeout: 20_000 }, async () => {
    const { fixtureFile } = await scenario({ prompt: 'error' })
    const result = await runScenario(
@@ -963,6 +1012,7 @@ describe('runScenario', () => {
    [{ op: 'waitForTurnStart' }, /waitForTurnStart before newSession/],
    [{ op: 'waitForTurnEnd' }, /waitForTurnEnd before newSession/],
    [{ op: 'waitForTitleAfterTurnEnd' }, /waitForTitleAfterTurnEnd before newSession/],
+    [{ op: 'waitForEventAfterTurnEnd', type: 'user/message' }, /waitForEventAfterTurnEnd before newSession/],
    [{ op: 'cancel' }, /cancel before newSession/],
  ] as [InputStep, RegExp][])('rejects %j before newSession', { timeout: 20_000 }, async (step, message) => {
    const { fixtureFile } = await scenario({})
--- a/packages/ui/tui/src/chat/timing.ts
+++ b/packages/ui/tui/src/chat/timing.ts
@@ -132,32 +132,58 @@ function timingTotalsAt(state: TimingState, at?: number): TimingTotals {
  return totals
 }

+function stepKey(position: StepPosition): string {
+  return `${position.turn}:${position.step}`
+}
+
+interface TrackedStep extends TimingState {
+  /** Set at the step's `step/end`; later same-coordinate events no longer advance the step. */
+  closed: boolean
+}
+
 /**
- * Replay one step's accumulated per-phase timing up to clock `at`.
- * @param events - Session events to replay.
- * @param position - Turn/step coordinates of the step.
- * @param at - Render clock to accumulate the open bucket up to.
- * @returns The step's per-phase totals.
+ * Incremental per-step timing accumulator shared by every step's timing footer
+ * in one transcript. One forward pass over the append-only session log serves
+ * all steps' totals: each query advances a cursor over the events appended
+ * since the previous query, so a transcript of S steps costs O(events) in
+ * total instead of the O(S × events) of replaying the whole log per footer
+ * ([rationale](../../../../../.agents/notes/implemented/bug-fix/2026-08-03-tui-long-session-render-costs.md)).
+ *
+ * The log must be append-only with stable indices (the session `seq = log
+ * length` contract). Event times are consumed as logged: a backward wall-clock
+ * step clamps each bucket at zero rather than cutting the scan off at the
+ * query clock. The open bucket is accumulated to the query clock at lookup,
+ * never during the scan.
 */
-export function stepTimingAt(
-  events: readonly SessionEvent[],
-  position: StepPosition,
-  at: number,
-): TimingTotals {
-  const startIndex = events.findIndex(event => event.type === 'step/start' && sameStep(event, position))
-  if (startIndex < 0) return emptyTimingTotals()
-  const start = events[startIndex] as Extract<SessionEvent, { type: 'step/start' }>
-  const state = timingState(start.time)
-  for (let index = startIndex + 1; index < events.length; index += 1) {
-    const event = events[index] as SessionEvent
-    if (event.time > at) break
-    if ((event.type === 'assistant/chunk' || event.type === 'tool/call' || event.type === 'step/end')
-      && sameStep(event, position)) {
-      advanceStepTiming(state, event)
-      if (event.type === 'step/end') break
+export class StepTimingTracker {
+  private scanned = 0
+  private readonly steps = new Map<string, TrackedStep>()
+
+  /**
+   * Advance over events appended since the previous query, then return one
+   * step's accumulated per-phase timing up to clock `at`.
+   * @param events - Current session event log (append-only).
+   * @param position - Turn/step coordinates of the queried step.
+   * @param at - Render clock to accumulate the open bucket up to.
+   * @returns The step's per-phase totals; empty when the step never started.
+   */
+  totalsAt(events: readonly SessionEvent[], position: StepPosition, at: number): TimingTotals {
+    for (; this.scanned < events.length; this.scanned += 1) {
+      const event = events[this.scanned] as SessionEvent
+      if (event.type === 'step/start') {
+        const key = stepKey(event.data)
+        if (!this.steps.has(key)) this.steps.set(key, { ...timingState(event.time), closed: false })
+      } else if (event.type === 'assistant/chunk' || event.type === 'tool/call' || event.type === 'step/end') {
+        const state = this.steps.get(stepKey(event.data))
+        if (state !== undefined && !state.closed) {
+          advanceStepTiming(state, event)
+          if (event.type === 'step/end') state.closed = true
+        }
+      }
    }
+    const state = this.steps.get(stepKey(position))
+    return state === undefined ? emptyTimingTotals() : timingTotalsAt(state, at)
  }
-  return timingTotalsAt(state, at)
 }

 /**
@@ -191,7 +217,7 @@ const COMPACTING_GLYPH = '⊙'
 /**
 * Derive the currently open step's active timing bucket, or `undefined` when no
 * step is open. The open step is the last `step/start` with no later matching
- * `step/end`; its bucket is replayed with the same rules as {@link stepTimingAt}.
+ * `step/end`; its bucket is replayed with the same rules as {@link StepTimingTracker}.
 * @param events - Session events to scan.
 * @returns The open step's active bucket, or `undefined`.
 */
--- a/packages/ui/tui/src/components/transcript.ts
+++ b/packages/ui/tui/src/components/transcript.ts
@@ -33,8 +33,8 @@ import { contentText, type ParsedArguments } from './content.ts'
 import {
  formatCompletionTime,
  formatTimingTotals,
-  stepTimingAt,
  type StepPosition,
+  type StepTimingTracker,
 } from '../chat/timing.ts'

 /** Concatenate the text of every block of one type, separated by blank lines. */
@@ -228,6 +228,7 @@ class StepTimingComponent extends Container {
  constructor(
    private readonly position: StepPosition,
    private readonly events: () => readonly SessionEvent[],
+    private readonly tracker: StepTimingTracker,
    private readonly now: () => number,
    private readonly palette: Palette,
  ) {
@@ -247,7 +248,7 @@ class StepTimingComponent extends Container {

  private rebuild(): void {
    this.clear()
-    const totals = stepTimingAt(this.events(), this.position, this.completionTime ?? this.now())
+    const totals = this.tracker.totalsAt(this.events(), this.position, this.completionTime ?? this.now())
    const timing = formatTimingTotals(totals, true)
    const header = this.completionTime === undefined
      ? timing
@@ -277,13 +278,14 @@ export class StreamingAssistantComponent extends Container {
    /** The step's turn/step coordinates, used to group steps into their turn. */
    readonly position: StepPosition,
    events: () => readonly SessionEvent[],
+    tracker: StepTimingTracker,
    now: () => number,
    private showReasoning: boolean,
    private readonly palette: Palette,
    private readonly mdTheme: MarkdownTheme,
  ) {
    super()
-    this.timing = new StepTimingComponent(position, events, now, palette)
+    this.timing = new StepTimingComponent(position, events, tracker, now, palette)
    this.rebuild()
  }

@@ -409,8 +411,43 @@ interface CardBody {
 */
 export type ToolCardVisibility = 'hidden' | 'collapsed' | 'expanded'

+/**
+ * Transcript card with a width-keyed rendered-row cache. pi-tui re-renders
+ * every component each frame and relies on per-component line caches (its own
+ * `Text`/`Markdown` do this); a card that rebuilds rows inside `render(width)`
+ * would re-wrap its output every frame
+ * ([rationale](../../../../../.agents/notes/implemented/bug-fix/2026-08-03-tui-long-session-render-costs.md)).
+ * Subclasses render through {@link renderLines} and call {@link dropLines}
+ * from every state mutator; with `invalidate()` (pi-tui's tree-wide cascade)
+ * also dropping, a state change always re-renders.
+ */
+abstract class CachedCardComponent implements Component {
+  private cached: { width: number; lines: string[] } | undefined
+
+  /** Discard the cached rows so the next render recomputes them. */
+  protected dropLines(): void {
+    this.cached = undefined
+  }
+
+  invalidate(): void {
+    this.cached = undefined
+  }
+
+  render(width: number): string[] {
+    if (this.cached?.width !== width) this.cached = { width, lines: this.renderLines(width) }
+    return this.cached.lines
+  }
+
+  /**
+   * Render the card's rows for `width` without caching.
+   * @param width - Render width the rows are wrapped to.
+   * @returns The card's rows.
+   */
+  protected abstract renderLines(width: number): string[]
+}
+
 /** A tool call and its result, rendered as a collapsible status card. */
-export class ToolCardComponent implements Component {
+export class ToolCardComponent extends CachedCardComponent {
  private result: { content: ContentBlock[]; isError: boolean; meta?: JsonValue } | undefined
  private visibility: ToolCardVisibility = 'collapsed'
  private callView: ToolCallView
@@ -426,6 +463,7 @@ export class ToolCardComponent implements Component {
    private readonly palette: Palette,
    private readonly mdTheme: MarkdownTheme,
  ) {
+    super()
    this.callView = this.presentCall()
  }

@@ -447,6 +485,7 @@ export class ToolCardComponent implements Component {
   */
  updateResult(event: Extract<SessionEvent, { type: 'tool/result' }>['data']): void {
    this.diffBodyCache = undefined
+    this.dropLines()
    const result = event.message.content[0]
    this.result = {
      content: [...result.content],
@@ -469,11 +508,10 @@ export class ToolCardComponent implements Component {
   */
  setVisibility(visibility: ToolCardVisibility): void {
    this.visibility = visibility
+    this.dropLines()
  }

-  invalidate(): void {}
-
-  render(width: number): string[] {
+  protected renderLines(width: number): string[] {
    // Hidden renders nothing — not even the leading gap — so the transcript
    // keeps only the conversation, the way Codex hides tool calls.
    if (this.visibility === 'hidden') return []
@@ -725,7 +763,7 @@ function stripReminderFrame(text: string): string {
 * well-formed XML, which made both the fold and the frame-line suppression
 * content-dependent.
 */
-export class ContextCardComponent implements Component {
+export class ContextCardComponent extends CachedCardComponent {
  private expanded = false

  constructor(
@@ -733,7 +771,9 @@ export class ContextCardComponent implements Component {
    private readonly text: string,
    private readonly maxOutputLines: number,
    private readonly palette: Palette,
-  ) {}
+  ) {
+    super()
+  }

  /**
   * Expand or collapse the card body.
@@ -741,11 +781,10 @@ export class ContextCardComponent implements Component {
   */
  setExpanded(expanded: boolean): void {
    this.expanded = expanded
+    this.dropLines()
  }

-  invalidate(): void {}
-
-  render(width: number): string[] {
+  protected renderLines(width: number): string[] {
    const header = this.palette.dim(`Context · ${displayText(this.label)}`)
    // Emptiness is decided on the stripped text: styling a blank body would yield
    // one escape-only row, which reads as a stray blank line under the header.
--- a/packages/ui/tui/src/index.ts
+++ b/packages/ui/tui/src/index.ts
@@ -88,6 +88,7 @@ import {
  runningPhaseGlyph,
  STATUS_ANIMATION_INTERVAL_MS,
  STATUS_FADE_MS,
+  StepTimingTracker,
  TIMING_BUCKET_GLYPHS,
  type StepPosition,
 } from './chat/timing.ts'
@@ -358,6 +359,9 @@ export function createTuiChat(
  let toolsVisibility: ToolCardVisibility = 'collapsed'
  let streaming: StreamingAssistantComponent | undefined
  let completedStreaming: StreamingAssistantComponent | undefined
+  // One shared accumulator serves every step's timing footer; per-footer
+  // replay of the whole log is quadratic on a long resumed session.
+  const stepTimingTracker = new StepTimingTracker()
  // Assistant step components in model order per turn, for hidden-mode folding:
  // with tool cards hidden, a turn keeps one Assistant header and later steps
  // render as headerless continuations (see applyTurnFolding).
@@ -769,6 +773,7 @@ export function createTuiChat(
    streaming = new StreamingAssistantComponent(
      position,
      () => agent.session.events,
+      stepTimingTracker,
      now,
      showReasoning,
      palette,
--- a/packages/ui/tui/tests/timing-tracker.spec.ts
+++ b/packages/ui/tui/tests/timing-tracker.spec.ts
@@ -0,0 +1,90 @@
+import { describe, expect, it } from 'vitest'
+import type { SessionEvent } from '@deepseek-ai/dsh-session'
+import { StepTimingTracker } from '../src/chat/timing.ts'
+
+/** One completed two-phase step plus a tool call, in event-log order. */
+function stepEvents(turn: number, step: number, base: number, seq: number): SessionEvent[] {
+  return [
+    { type: 'step/start', seq: seq, time: base, data: { turn, step } },
+    { type: 'assistant/chunk', seq: seq + 1, time: base + 100, data: { turn, step, chunk: { type: 'block-start', index: 0, blockType: 'reasoning' } } },
+    { type: 'assistant/chunk', seq: seq + 2, time: base + 300, data: { turn, step, chunk: { type: 'text-delta', index: 1, text: 'hi' } } },
+    { type: 'tool/call', seq: seq + 3, time: base + 450, data: { turn, step, callId: 'call-1', name: 'bash', arguments: '{}' } },
+    { type: 'step/end', seq: seq + 4, time: base + 700, data: { turn, step } },
+  ] as SessionEvent[]
+}
+
+describe('StepTimingTracker', () => {
+  it('accumulates each phase from the step lifecycle', () => {
+    const tracker = new StepTimingTracker()
+    const events = stepEvents(1, 1, 1_000, 0)
+    expect(tracker.totalsAt(events, { turn: 1, step: 1 }, 2_000)).toEqual({
+      ttft: 100, // step/start -> first chunk
+      thinking: 200, // reasoning block-start -> text delta
+      responding: 150, // text delta -> tool call
+      tools: 250, // tool call -> step/end
+    })
+  })
+
+  it('returns empty totals for a step that never started', () => {
+    const tracker = new StepTimingTracker()
+    expect(tracker.totalsAt(stepEvents(1, 1, 1_000, 0), { turn: 9, step: 9 }, 2_000)).toEqual({
+      ttft: 0, thinking: 0, responding: 0, tools: 0,
+    })
+  })
+
+  it('accumulates the open bucket to the query clock without mutating tracked state', () => {
+    const tracker = new StepTimingTracker()
+    const events = [
+      { type: 'step/start', seq: 0, time: 1_000, data: { turn: 1, step: 1 } },
+    ] as SessionEvent[]
+    expect(tracker.totalsAt(events, { turn: 1, step: 1 }, 1_250).ttft).toBe(250)
+    expect(tracker.totalsAt(events, { turn: 1, step: 1 }, 1_400).ttft).toBe(400)
+  })
+
+  it('matches a fresh replay when queried incrementally across appends', () => {
+    const incremental = new StepTimingTracker()
+    const first = stepEvents(1, 1, 1_000, 0)
+    incremental.totalsAt(first, { turn: 1, step: 1 }, 5_000)
+    const events = [...first, ...stepEvents(1, 2, 3_000, first.length)]
+    const fresh = new StepTimingTracker()
+    for (const position of [{ turn: 1, step: 1 }, { turn: 1, step: 2 }]) {
+      expect(incremental.totalsAt(events, position, 5_000)).toEqual(fresh.totalsAt(events, position, 5_000))
+    }
+  })
+
+  it('serves interleaved steps from one shared scan', () => {
+    const tracker = new StepTimingTracker()
+    const events = [
+      { type: 'step/start', seq: 0, time: 1_000, data: { turn: 1, step: 1 } },
+      { type: 'step/start', seq: 1, time: 1_100, data: { turn: 1, step: 2 } },
+      { type: 'assistant/chunk', seq: 2, time: 1_200, data: { turn: 1, step: 2, chunk: { type: 'text-delta', index: 0, text: 'x' } } },
+      { type: 'step/end', seq: 3, time: 1_500, data: { turn: 1, step: 2 } },
+      { type: 'step/end', seq: 4, time: 1_600, data: { turn: 1, step: 1 } },
+    ] as SessionEvent[]
+    expect(tracker.totalsAt(events, { turn: 1, step: 1 }, 9_000)).toEqual({ ttft: 600, thinking: 0, responding: 0, tools: 0 })
+    expect(tracker.totalsAt(events, { turn: 1, step: 2 }, 9_000)).toEqual({ ttft: 100, thinking: 0, responding: 300, tools: 0 })
+  })
+
+  it('keeps the first step/start when a duplicate arrives while the step is open', () => {
+    const tracker = new StepTimingTracker()
+    const events = [
+      { type: 'step/start', seq: 0, time: 1_000, data: { turn: 1, step: 1 } },
+      { type: 'step/start', seq: 1, time: 1_500, data: { turn: 1, step: 1 } },
+    ] as SessionEvent[]
+    expect(tracker.totalsAt(events, { turn: 1, step: 1 }, 2_000).ttft).toBe(1_000)
+  })
+
+  it('ignores same-coordinate events after the step closed', () => {
+    const tracker = new StepTimingTracker()
+    const events = [
+      ...stepEvents(1, 1, 1_000, 0),
+      // A stray duplicate start and a late chunk reuse the coordinates; the
+      // closed step's totals stay pinned.
+      { type: 'step/start', seq: 5, time: 9_000, data: { turn: 1, step: 1 } },
+      { type: 'assistant/chunk', seq: 6, time: 9_100, data: { turn: 1, step: 1, chunk: { type: 'text-delta', index: 0, text: 'late' } } },
+    ] as SessionEvent[]
+    expect(tracker.totalsAt(events, { turn: 1, step: 1 }, 10_000)).toEqual({
+      ttft: 100, thinking: 200, responding: 150, tools: 250,
+    })
+  })
+})
--- a/packages/ui/tui/tests/transcript-card-cache.spec.ts
+++ b/packages/ui/tui/tests/transcript-card-cache.spec.ts
@@ -0,0 +1,74 @@
+import { describe, expect, it } from 'vitest'
+import type { SessionEvent } from '@deepseek-ai/dsh-session'
+import { createToolResultMessage, CallId } from '@deepseek-ai/dsh-llm'
+import { ContextCardComponent, ToolCardComponent } from '../src/components/transcript.ts'
+import { parseArguments } from '../src/components/content.ts'
+import { createPalette, markdownTheme } from '../src/components/theme.ts'
+
+const palette = createPalette(false)
+const mdTheme = markdownTheme(palette)
+
+function toolCard(): ToolCardComponent {
+  return new ToolCardComponent('bash', parseArguments('{"command":"ls"}'), undefined, 10, 2_000, palette, mdTheme)
+}
+
+function toolResult(text: string): Extract<SessionEvent, { type: 'tool/result' }>['data'] {
+  const message = createToolResultMessage({
+    callId: CallId('call-1'),
+    content: [{ type: 'text', text }],
+    isError: false,
+  })
+  return { turn: 1, step: 1, message }
+}
+
+// pi-tui re-renders every component each frame; the cards must serve repeat
+// same-width renders from their line cache and drop it on every state change.
+describe('transcript card render caches', () => {
+  it('tool card: repeat same-width renders return the cached rows', () => {
+    const card = toolCard()
+    const first = card.render(80)
+    expect(card.render(80)).toBe(first)
+    const narrower = card.render(60)
+    expect(narrower).not.toBe(first)
+    expect(card.render(60)).toBe(narrower)
+  })
+
+  it('tool card: result, visibility, and invalidate() each drop the cache', () => {
+    const card = toolCard()
+    const pending = card.render(80)
+    card.updateResult(toolResult('output line'))
+    const settled = card.render(80)
+    expect(settled).not.toBe(pending)
+    expect(settled.join('\n')).toContain('●')
+
+    card.setVisibility('hidden')
+    expect(card.render(80)).toEqual([])
+
+    card.setVisibility('collapsed')
+    const restored = card.render(80)
+    expect(restored).toEqual(settled)
+    expect(restored).not.toBe(settled)
+
+    card.invalidate()
+    expect(card.render(80)).not.toBe(restored)
+  })
+
+  it('context card: caches by width and drops on setExpanded and invalidate()', () => {
+    const card = new ContextCardComponent('workspace-context', 'line one\nline two', 10, palette)
+    const first = card.render(80)
+    expect(card.render(80)).toBe(first)
+
+    // Same width across the mutation, so a hit here would prove a kept cache.
+    card.setExpanded(true)
+    const expanded = card.render(80)
+    expect(expanded).not.toBe(first)
+    expect(card.render(80)).toBe(expanded)
+
+    card.invalidate()
+    const reRendered = card.render(80)
+    expect(reRendered).not.toBe(expanded)
+    expect(reRendered).toEqual(expanded)
+
+    expect(card.render(60)).not.toBe(reRendered)
+  })
+})