Merge remote-tracking branch 'origin/master' into codex/sandbox-policy-context

# Conflicts:
#	examples/acp-agent/tests/snapshots/cordis-inspect-jsdoc/session.jsonl
#	examples/acp-agent/tests/snapshots/web-fetch/session.jsonl

.agents/notes/implemented/bug-fix/2026-07-30-approval-panel-command-cap.i18n.yaml

@@ -0,0 +1,6 @@
+# Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
+# 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/bug-fix/2026-07-30-approval-panel-command-cap.md
+2026-07-30-approval-panel-command-cap.md: 941f7eda187f263f2d8af6aa643d493c92a3669b
+2026-07-30-approval-panel-command-cap.zh.md: 939a700934f6467947028d988da9a694169e203e

.agents/notes/implemented/bug-fix/2026-07-30-approval-panel-command-cap.md

@@ -0,0 +1,52 @@
+# Agent Note: The approval takeover shares the composer's text cap
+
+Status: implemented
+
+English | [中文](2026-07-30-approval-panel-command-cap.zh.md)
+
+## Problem
+
+The approval panel is a composer takeover: while a sandbox escalation waits, it replaces the InputBar in the composer seat with the model's justification, the paired command, and a refuse/allow row. Both texts are unbounded model output, and the card had no height cap. A long command — the realistic shape, since escalation happens on the command the sandbox just denied, and a denied command is often a long inline write — grew the card until the action row left the viewport. The user could read the request and not answer it: the buttons existed, off screen, in a sticky footer that had already used the whole column.
+
+The InputBar the panel replaces has always been capped (14 lines, then the textarea scrolls), so the takeover was also the one composer state that could grow without limit — the seat's height jumped on election and jumped back on answer.
+
+## Decision
+
+The panel's justification and command move into one scroll region (`data-approval-scroll`) capped at the same height as the composer's draft area; the amber strip and the action row sit outside it, so both buttons are in the card at every content length.
+
+The cap is one value with two consumers, declared as `--dsh-composer-text-max-height: 336px` on `ConversationRoot`'s `.composerSeat` — the composer chain's only shared ancestor, since the fallback InputBar and an elected takeover render as siblings. `InputBar`'s mirror and the panel's scroll region both read it, so the seat cannot cap its two states differently: what the designer asked for ("unify it with the input box's max height") is now a fact of the stylesheet rather than a number repeated in two files. The region is `box-sizing: border-box` so the cap is its outer height, the same box the composer's draft area occupies.
+
+The region is a tab stop (`tabIndex={0}`, named `role="group"`). Unlike the question composer's scroll body, whose option rows are focusable and pull the container along, this one holds nothing but text: without its own tab stop a keyboard-only user could reach the buttons and never the command's tail, and approve what they could not finish reading.
+
+The panel's card rebinds `--dsh-scrollbar-thumb{,-hover}` to the l2 pair, as every scrolling surface on an elevated background must ([scrollbar contract](../../../../packages/client/ui-theme/src/styles/scrollbar.css)).
+
+## Alternatives considered
+
+**Cap the whole card instead of the text region.** One declaration, no restructuring, and it reads as the literal "same max height as the input box". Rejected because the card holds the strip and the action row: at 336px total the justification and command would get ~250px, less room than the draft they replace, and the numbers would only agree by coincidence of the strip's height. Capping the text region makes both seats top out at the same text height, which is the property that keeps the footer from jumping.
+
+**Cap against the viewport like the question composer (`min(60vh, 520px)`).** The sibling takeover already does this, so it is the local precedent. Rejected because the designer's request was parity with the InputBar, and the two takeovers are not the same shape: the question composer's scroll content is a list of options the user must compare, which wants as much viewport as it can get, while the approval panel's is one command the user skims before deciding. A viewport-relative cap would also make the seat's height jump on election again, in the other direction.
+
+**Ellipsize or truncate the command.** No scroll region, no cap, and the buttons stay put. Rejected because the command is the thing being approved: hiding its tail asks the user to consent to text they cannot read. Truncation is also unrecoverable here — the panel is the whole approval UI, so there is no "show more" surface to fall back to.
+
+**Leave the action row inside the scroll region and cap the region.** Fewer moving parts than pinning the row. Rejected because it reproduces the defect inside the card: the buttons scroll out of the region, and the user has to discover a scrollbar to reach them.
+
+## Consequences
+
+- A long command scrolls inside the card and the refuse/allow buttons stay on screen. Measured on the built client at 900x1000 and 900x700: the region reports `scrollHeight` past `clientHeight`, and both buttons stay inside the card and inside the viewport.
+- Electing the takeover no longer changes how tall the composer seat can get, so the transcript above it does not reflow by hundreds of pixels when an approval arrives or resolves.
+- The InputBar's 14-line cap now resolves through a custom property inherited from `.composerSeat`. Rendering the bar outside that seat would drop the declaration (an unresolved `var()` with no fallback), so a future composer host has to carry the property — which is why it is declared on the shared seat rather than the app root.
+- The scenario's recorded command is a 200-token blob, far longer than a round trip needs. That cost is deliberate: the cap is unfalsifiable without content that passes it, and the model compresses any regular payload (the first recording turned "alpha 400 times" into `printf 'alpha %.0s' {1..400}`, a one-line command that proves nothing).
+
+## Verification
+
+`apps/web/tests/approval-composer.e2e.ts` drives the real composition: a read-only session, a denied write, the model's escalation retry, and the answer clicked through the panel. The geometry assertion runs on the live panel at two viewport heights and is guarded against holding vacuously — the region must actually be scrolling, and the measured cap must equal the composer's own, which the test reads off the live textarea before sending rather than hardcoding the px value.
+
+Confirmed both directions against the built client. With the cap reverted, the region reports `scrolls: false` and grows to the command's full height (1798px for the recorded blob at 900x1000, against 336px capped); at 900x700 the card is 680px tall against a 700px viewport and the action row's bottom lands at y=749 — below the fold, the designer's report exactly. With the cap restored the scenario passes in replay.
+
+Reproducing the off-screen buttons needs a card taller than the scrollport, not merely a tall card. The composer seat is `position: sticky; bottom: 0`, so while the card still fits it stays pinned to the viewport bottom and the buttons remain visible — at 900x1000 the uncapped card ate the whole transcript yet kept its action row on screen. Only once the card outgrows the scrollport does sticky stop being able to hold the bottom edge, and the row goes under.
+
+The geometry block and the golden are replay-only, so record mode reaches the fixture write instead of aborting on layout.
+
+The scenario keeps exactly one golden — the waiting panel — and asserts the answered state on the world instead (the decided outcome, the file the escalated command wrote, `DONE`, the panel gone, the composer re-enabled). An answered-transcript golden was recorded first and failed on Linux CI: the denied first attempt renders the OS's own refusal, and that text is platform-specific (`bash: notes.txt: Operation not permitted` on macOS against `bash: line 1: notes.txt: Read-only file system` on Linux). Any scenario whose transcript contains a sandbox-denied command inherits that, so the denial belongs in assertions, never in a golden.
+
+The panel ships as a client-module bundle: `pnpm run build:web` alone does not pick up a change to `ApprovalPanel.module.css` or a new `data-` hook in `ApprovalPanel.tsx` — the package build must run first, or the browser lane asserts against an older client than the tree.

.agents/notes/implemented/bug-fix/2026-07-30-approval-panel-command-cap.zh.md

@@ -0,0 +1,52 @@
+# Agent Note: 审批接管面板与输入框共用同一文本高度上限
+
+Status: implemented
+
+[English](2026-07-30-approval-panel-command-cap.md) | 中文
+
+## 问题
+
+审批面板是一次 composer 接管：当一次沙箱越权申请处于等待状态时，它在 composer 容器中取代 InputBar，展示模型给出的理由、与之配对的命令，以及一行拒绝／允许按钮。这两段文本都是长度不受限的模型输出，而卡片当时没有任何高度上限。命令一长——而这正是现实中的常见形态，因为越权申请针对的就是沙箱刚刚拒绝的那条命令，而被拒绝的命令往往是一次很长的内联写入——卡片就会一直变高，直到操作按钮行离开视口。用户能读到这次申请，却无法回应它：按钮存在，只是在屏幕之外，位于一个已经占满整列的吸底容器里。
+
+被它取代的 InputBar 一直是有上限的（14 行，之后由 textarea 自行滚动），因此这次接管也是 composer 唯一一个可以无限增高的状态——被选中时容器高度骤增，回应之后又骤降。
+
+## 决策
+
+面板的理由与命令移入同一个滚动区域（`data-approval-scroll`），其高度上限与 composer 的草稿区完全相同；琥珀色状态条与操作按钮行位于该区域之外，因此无论内容多长，两个按钮都留在卡片内。
+
+这个上限是一个值、两个消费者，以 `--dsh-composer-text-max-height: 336px` 声明在 `ConversationRoot` 的 `.composerSeat` 上——它是 composer 链唯一的共同祖先，因为兜底的 InputBar 与被选中的接管面板是兄弟节点。`InputBar` 的 mirror 与面板的滚动区域都读取它，于是同一个容器不可能给它的两种状态设出不同上限：设计同学要求的"可以跟输入框最大高度统一"，如今是样式表中的一个事实，而不是抄在两个文件里的一个数字。该区域取 `box-sizing: border-box`，因此上限指的是它的外框高度，与 composer 草稿区占据的是同一个盒子。
+
+该区域自身是一个 Tab 停靠点（`tabIndex={0}`，带名称的 `role="group"`）。提问 composer 的滚动体不需要这样做——它的选项行本身可聚焦，会把容器一起带过去；而这里除文本之外别无内容：没有自己的停靠点，仅用键盘的用户能走到按钮却走不到命令尾部，于是可能批准了自己没读完的东西。
+
+面板卡片把 `--dsh-scrollbar-thumb{,-hover}` 重新绑定到 l2 那一对，这是每一个位于高层表面上的滚动区域都必须做的（[滚动条约定](../../../../packages/client/ui-theme/src/styles/scrollbar.css)）。
+
+## 曾考虑的替代方案
+
+**给整张卡片设上限，而不是给文本区域设。** 一条声明，不需要重构结构，而且它读起来就是字面意义上的"与输入框相同的最大高度"。之所以否决：卡片还装着状态条和操作按钮行——总高 336px 时，理由与命令只能分到约 250px，比它们所取代的草稿区更矮，而且两边数字能对上纯属状态条高度的巧合。给文本区域设上限，才能让两种状态在同一文本高度处收住，而这正是让底部不再跳动的那条性质。
+
+**像提问 composer 那样按视口设上限（`min(60vh, 520px)`）。** 同为接管面板的兄弟组件已经这么做了，因此这是本地既有先例。之所以否决：设计同学的要求是与 InputBar 对齐，而两个接管面板形态并不相同——提问 composer 的滚动内容是一组需要用户互相比较的选项，能占多少视口就该占多少；审批面板的滚动内容则是一条命令，用户在决定之前扫读即可。按视口设上限还会让容器高度在被选中时再次跳动，只是方向相反。
+
+**对命令做省略号或截断处理。** 不需要滚动区域，不需要上限，按钮也不会移位。之所以否决：命令正是被审批的对象，隐去它的尾部等于要求用户为自己读不到的文本背书。在这里截断还是不可恢复的——面板就是审批的全部界面，没有"展开更多"的落脚处。
+
+**把操作按钮行留在滚动区域内，只给该区域设上限。** 比把按钮行固定住少动几处。之所以否决：这会把缺陷搬进卡片内部——按钮滚出该区域，用户得先发现有滚动条才能碰到它们。
+
+## 后果
+
+- 长命令在卡片内滚动，拒绝／允许按钮留在屏幕内。在构建产物客户端上于 900x1000 与 900x700 实测：该区域报告的 `scrollHeight` 超过 `clientHeight`，两个按钮都留在卡片内、也都留在视口内。
+- 选中接管面板不再改变 composer 容器能达到的高度，因此审批到来或解决时，上方的会话流不会有数百像素的重排。
+- InputBar 的 14 行上限现在通过一个自 `.composerSeat` 继承而来的自定义属性解析。把输入栏渲染到该容器之外会丢掉这条声明（一个没有兜底值的未解析 `var()`），因此未来的 composer 宿主必须带上这个属性——这也正是它声明在共享容器上、而不是应用根节点上的原因。
+- 该场景录制的命令是一段 200 个 token 的字符块，远超一次往返所需。这个代价是有意付出的：没有能越过上限的内容，这个上限无法被证伪，而模型会把任何规整的载荷压缩掉（第一次录制时，模型把"alpha 重复 400 次"写成了 `printf 'alpha %.0s' {1..400}`，一条什么也证明不了的单行命令）。
+
+## 验证
+
+`apps/web/tests/approval-composer.e2e.ts` 驱动的是真实组合：一个只读会话、一次被拒绝的写入、模型的越权重试，以及在面板上点击完成的回应。几何断言在两个视口高度上针对活动面板执行，并有守卫防止它空洞地成立——该区域必须确实处在滚动状态，且实测上限必须等于 composer 自身的上限，后者由测试在发送之前从活动 textarea 上读出，而不是把该像素值写死。
+
+在构建产物客户端上双向确认过。撤销上限后，该区域报告 `scrolls: false`，并长到命令的完整高度（900x1000 下，录制的字符块为 1798px，而设上限后为 336px）；在 900x700 下卡片高 680px、视口高 700px，操作按钮行底边落在 y=749——正在折叠之下，与设计同学的反馈完全一致。恢复上限后，该场景在回放模式下通过。
+
+要复现按钮跑到屏幕外，需要的是比滚动视口更高的卡片，而不只是一张很高的卡片。composer 容器为 `position: sticky; bottom: 0`，因此在卡片尚能容纳时它会一直吸附在视口底部，按钮仍然可见——在 900x1000 下，未设上限的卡片吃掉了整个会话流，却仍把操作按钮行留在屏幕内。只有当卡片长过滚动视口，sticky 才再也无法守住底边，按钮行随之沉入折叠之下。
+
+几何断言块与 golden 仅在回放模式下执行，这样录制模式才能走到写入 fixture 那一步，而不是在布局检查处中断。
+
+该场景只保留一份 golden —— 等待中的面板；回应之后的状态改为对世界作断言（决策结果、越权命令写出的那个文件、`DONE`、面板消失、输入框重新可用）。最初还录了一份"已回应会话流"的 golden，它在 Linux CI 上失败了：第一次被拒绝的尝试渲染的是操作系统自己的拒绝文本，而这段文本因平台而异（macOS 为 `bash: notes.txt: Operation not permitted`，Linux 为 `bash: line 1: notes.txt: Read-only file system`）。任何会话流中含有被沙箱拒绝命令的场景都会继承这一点，因此这类拒绝只能进断言，绝不能进 golden。
+
+该面板以客户端模组包的形式发布：单跑 `pnpm run build:web` 不会带上对 `ApprovalPanel.module.css` 的改动，也不会带上 `ApprovalPanel.tsx` 中新增的 `data-` 钩子——必须先执行包构建，否则浏览器测试通道会对着一个比工作树更旧的客户端做断言。

.agents/notes/implemented/feature/2026-07-30-web-result-card.i18n.yaml

@@ -0,0 +1,6 @@
+# Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
+# 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/2026-07-30-web-result-card.md
+2026-07-30-web-result-card.md: deec27832aba2d5d868889f7306cbaef4f0b90b4
+2026-07-30-web-result-card.zh.md: 037e029332fbb665d90860d7e11c2fd117e6eb45

.agents/notes/implemented/feature/2026-07-30-web-result-card.md

@@ -0,0 +1,44 @@
+# Agent Note: Web result card — a structured render intent for web_search and web_fetch
+
+Status: implemented
+
+English | [中文](2026-07-30-web-result-card.zh.md)
+
+## Problem
+
+The `web_search` and `web_fetch` tools each declared a generic pending card (`presentCall`, `kind: 'search'`/`'fetch'`) but no `presentResult`, so a completed web call reached a UI only as the model-facing render text. For a web frontend that wants to render a citation list or a fetch summary, that text is lossy: `web_search`'s render collapses each source's `title`, `snippet`, and `publishedAt` into one free-text markdown line labelled by title OR hostname (`formatSearchOutput` in `packages/web/tool-web/src/search.ts`), so reparsing the render cannot recover the per-source fields; and `web_fetch`'s render carries `url` and `statusCode` only in a header line. The render-intent contract ([tagged union](../architecture/2026-07-02-tool-render-intent-union.md)) had no arm a web tool could declare to carry a structured result.
+
+## Decision
+
+Add one `card: 'web'` result arm to `ToolResultView` (`packages/core/tools/src/presentation.ts`), a union `WebResultView = WebSearchResultView | WebFetchResultView` discriminated by a `kind: 'search' | 'fetch'` field, plus a `WebSource` shape for one citeable source. Both tools now declare `presentResult`.
+
+One tag with a `kind` discriminant, not two tags. Both calls are web retrieval and a web frontend renders them with one component family (a retrieval card whose body differs by kind), so a shared `card` keeps every card consumer's switch to one added arm and lets the frontend branch on `kind` inside it. Two tags would force every present and future consumer to add two arms for what is one visual family. The `kind` values match the two tools' existing generic call-view `kind`s, so a call and its result read as the same category.
+
+`presentationMeta` carries what render text cannot. The structured result object a tool returns from `execute` does NOT reach a client over the wire — only the model-facing `render` text and, when declared, the `output.presentationMeta` JSON projected onto the `tool/result` event's `meta` do. For `web_search` the meta is the ONLY faithful route to `{url, title?, snippet?, publishedAt?}`: the render collapses those fields into one lossy free-text line, so a consumer cannot reparse them. For `web_fetch` the meta is a smaller but real gain: `url`/`statusCode` are recoverable from the deterministic `Fetched <url> (HTTP <n>)` header line, but `truncated` is the effective truncation — provider cap, pre-conversion source cut, or the deployment's `fetchMaxOutputChars` output cap — which a client cannot recompute because it does not know that cap. The fetch card and the model-facing text derive `truncated` from one shared `renderFetchOutput(result, maxOutputChars)` helper, so the card never disagrees with the footer the model saw. This mirrors the write/edit diff template (`packages/fs/tool-fs/src/diff.ts`): a `*MetaFromValue` projector feeds `output.presentationMeta`, and a `*MetaFromResult` narrower reads `result.meta` back with a defensive fallback to the generic card. `web_fetch`'s body is already markdown in the result content, so it is not duplicated into meta.
+
+Neither result view carries a `content` copy. A UI that does not render the structured `web` card falls back to the raw `tool/result` content. The TUI does exactly this: it renders no structured web body, and its transcript renderer routes a `web` view's fallback content through the same dim Markdown path as a generic card's content (`packages/ui/tui/src/components/transcript.ts`, where both `render` and `renderBody` narrow the `generic` arm to `view.content` and give a `web` view the same `this.result?.content` fallback). Copying the result content into the view would duplicate up to `fetchMaxOutputChars` characters on the same delivered frame for no gain (the same rejection the meta section applies to the fetch body), so the views omit it and the fallback path renders the identical text. Each view sets its result-state `title` from the call args (`args.query` / `args.url`) so a window-truncated replay that dropped the call head still has a title, the way write/edit reset title at result time.
+
+`presentResult` returns `undefined` (the generic card) on an error result and on absent or malformed `meta`, because presentation runs on replay of arbitrary logged results (possibly from an older schema) and must never throw. The narrowers validate every field defensively; an empty source list is valid meta, not malformed.
+
+## Consequences
+
+The web frontend consumer is a separate later PR: this PR adds the contract arm and makes the two tools emit it, with no client-side rendering. The one observable change is that the `web_search`/`web_fetch` `tool/result` events now persist a `data.meta` payload (the `web-fetch` keyless snapshot is refreshed accordingly); the model-facing render text and the TUI presentation are unchanged (the TUI falls back to the same result content). The assembled-application transcript snapshot that exercises a `web` card belongs to the consumer PR that renders it, delivered there. Any existing `ToolResultView` consumer that switches exhaustively must add a `web` arm; the TUI does not switch exhaustively and needs none. `apiproxy`'s session schema already accepts any `card` string (`packages/host/apiproxy/src/api/sessions.schema.ts`), so the new view crosses the wire without a schema change.
+
+A future web tool that wants this card declares `presentResult` returning a `card: 'web'` view with its own `kind`; adding a third `kind` is a union edit plus the frontend's branch, not a new card tag.
+
+## Alternatives considered
+
+**Two card tags (`web-search`, `web-fetch`).** Rejected: it doubles the arm count at every card consumer for one visual family, and the two shapes already share enough (a titled retrieval card with fallback content) that a `kind` discriminant expresses the difference without a second tag.
+
+**Reparse the render text in `presentResult` instead of projecting meta.** Rejected for `web_search`: the render's source list is lossy (title-or-hostname label, snippet and date concatenated into free text), so reparsing cannot faithfully recover the structured fields. `presentationMeta` is the only route that preserves them.
+
+**Carry the fetch body in meta, or copy the result content into either view.** Rejected: the body is already the model-facing markdown in the result content, and duplicating it into meta or into a view `content` field would double the persisted or delivered payload for no gain; a UI without the `web` capability falls back to the existing result content, which is the same text.
+
+## Testing
+
+`packages/web/tool-web/tests/tool-web.spec.ts` covers, per-file to the 100% gate: `searchMetaFromValue`/`fetchMetaFromValue` projection including omission of absent optional fields, and the fetch `truncated` projection agreeing with the render footer both when only the output cap cut the body and when nothing did; `searchMetaFromResult`/`fetchMetaFromResult` narrowing with a round-trip and every malformed-shape rejection (non-object, wrong field types, a malformed source entry) plus the empty-source-list accept; `presentSearchResult`/`presentFetchResult` typed views including the args-derived title, the absence of a `content` copy, the truncated signal, the error-result fallback, and the malformed-meta fallback; and two real-registry executions asserting the tool projects the meta onto `result.meta` and its registered `presentResult` derives the `card: 'web'` view.
+
+## Related
+
+- [Tagged render-intent union for tool-call presentation](../architecture/2026-07-02-tool-render-intent-union.md) — the `card`-tagged vocabulary this extends with the `web` arm.
+- [Web terminal card](2026-07-28-web-terminal-card.md) — the precedent that carried the bash `terminal` render intent to the browser; the web frontend consumer of this arm is its analogue, deferred to a later PR.

.agents/notes/implemented/feature/2026-07-30-web-result-card.zh.md

@@ -0,0 +1,44 @@
+# Agent Note: Web result card — a structured render intent for web_search and web_fetch
+
+Status: implemented
+
+[English](2026-07-30-web-result-card.md) | 中文
+
+## Problem
+
+`web_search` 与 `web_fetch` 工具各自声明了一个 generic 待定卡片（`presentCall`，`kind: 'search'`/`'fetch'`），但没有 `presentResult`，因此一个已完成的 web 调用抵达 UI 时只剩下面向模型的 render 文本。对于想渲染引用列表或抓取摘要的 web 前端而言，该文本是有损的：`web_search` 的 render 把每个来源的 `title`、`snippet`、`publishedAt` 压进一行以 title 或 hostname 标注的自由文本 markdown（`packages/web/tool-web/src/search.ts` 中的 `formatSearchOutput`），因此重新解析 render 无法恢复各来源字段；`web_fetch` 的 render 也仅在一行 header 里携带 `url` 与 `statusCode`。渲染意图契约（[标签联合类型](../architecture/2026-07-02-tool-render-intent-union.md)）此前没有一个可供 web 工具声明、用以携带结构化结果的分支。
+
+## Decision
+
+向 `ToolResultView`（`packages/core/tools/src/presentation.ts`）新增一个 `card: 'web'` 结果分支，它是以 `kind: 'search' | 'fetch'` 字段作判别的联合 `WebResultView = WebSearchResultView | WebFetchResultView`，并附一个表示单个可引用来源的 `WebSource` 形状。两个工具现在都声明 `presentResult`。
+
+采用一个标签加 `kind` 判别，而非两个标签。两个调用都是 web 检索，web 前端会用同一族组件渲染它们（一个检索卡片，正文按 kind 不同），因此共用一个 `card` 让每个 card 消费者的 switch 只需新增一个分支，并让前端在其内部按 `kind` 分岔。两个标签会迫使当前及未来每个消费者为本属同一视觉族的东西添加两个分支。这两个 `kind` 取值与两个工具既有的 generic 调用视图 `kind` 一致，因此一个调用与它的结果读起来是同一类别。
+
+`presentationMeta` 携带 render 文本无法携带的东西。工具从 `execute` 返回的结构化结果对象**不会**经由 wire 抵达客户端——只有面向模型的 `render` 文本，以及（声明时）投影到 `tool/result` 事件 `meta` 上的 `output.presentationMeta` JSON 会。对 `web_search`，meta 是得到 `{url, title?, snippet?, publishedAt?}` 的**唯一**忠实途径：render 把这些字段压进一行有损的自由文本，消费者无法重新解析。对 `web_fetch`，meta 是更小但真实的收益：`url`/`statusCode` 可从确定格式的 `Fetched <url> (HTTP <n>)` header 行还原，但 `truncated` 是有效截断——provider cap、转换前源截断，或部署的 `fetchMaxOutputChars` 输出上限——客户端无法重算，因为它不知道那个上限。抓取卡片与面向模型的文本都从同一个 `renderFetchOutput(result, maxOutputChars)` helper 派生 `truncated`，因此卡片绝不会与模型看到的脚注分叉。这照搬 write/edit 的 diff 模板（`packages/fs/tool-fs/src/diff.ts`）：一个 `*MetaFromValue` 投影器喂给 `output.presentationMeta`，一个 `*MetaFromResult` 收窄器读回 `result.meta`，并在失败时防御性回退到 generic 卡片。`web_fetch` 的正文已是结果内容中的 markdown，因此不重复写入 meta。
+
+两个结果视图都不携带 `content` 副本。不渲染结构化 `web` 卡片的 UI 回退到原始 `tool/result` 内容。TUI 正是如此：它不渲染结构化的 web 正文，其 transcript 渲染器把 `web` 视图的回退内容与 generic 卡片的内容路由进同一条 dim Markdown 路径（`packages/ui/tui/src/components/transcript.ts` 中 `render` 与 `renderBody` 都把 `generic` 分支收窄为 `view.content`，并给 `web` 视图相同的 `this.result?.content` 回退）。把结果内容复制进视图会在同一投递帧上重复最多 `fetchMaxOutputChars` 个字符却毫无收益（与 meta 一节对抓取正文的否决同理），因此视图省略它，回退路径渲染完全相同的文本。每个视图从调用参数设置其结果期 `title`（`args.query`／`args.url`），因此丢掉了调用头的窗口截断重放仍有标题，与 write/edit 在结果期重设 title 的做法一致。
+
+`presentResult` 在错误结果、以及 `meta` 缺失或畸形时返回 `undefined`（即 generic 卡片），因为 presentation 会在对任意已记录结果（可能来自旧 schema）的重放中运行，绝不能抛错。收窄器防御性地校验每个字段；空来源列表是有效 meta，而非畸形。
+
+## Consequences
+
+web 前端消费者是一个独立的后续 PR：本 PR 新增契约分支并让两个工具发出它，不含客户端渲染。唯一可观察的变化是 `web_search`/`web_fetch` 的 `tool/result` 事件现在持久化一个 `data.meta` 载荷（`web-fetch` keyless 快照随之刷新）；面向模型的 render 文本与 TUI 呈现不变（TUI 回退到相同的结果内容）。渲染 `web` 卡片的组装应用 transcript 快照属于渲染它的消费者 PR，在那里交付。任何做穷尽 switch 的现有 `ToolResultView` 消费者都必须新增一个 `web` 分支；TUI 并不穷尽 switch，无需新增。`apiproxy` 的会话 schema 已接受任意 `card` 字符串（`packages/host/apiproxy/src/api/sessions.schema.ts`），因此新视图无需 schema 变更即可跨 wire。
+
+未来想用此卡片的 web 工具，声明一个返回带自有 `kind` 的 `card: 'web'` 视图的 `presentResult`；新增第三个 `kind` 是一次联合类型编辑加前端的分岔，而非一个新的 card 标签。
+
+## Alternatives considered
+
+**两个 card 标签（`web-search`、`web-fetch`）。** 否决：它在每个 card 消费者处为一个视觉族翻倍分支数，而两个形状已共享得够多（一个带回退内容的带标题检索卡片），`kind` 判别无需第二个标签即可表达差异。
+
+**在 `presentResult` 里重新解析 render 文本，而非投影 meta。** 对 `web_search` 否决：render 的来源列表是有损的（title 或 hostname 标签，snippet 与日期拼进自由文本），因此重新解析无法忠实恢复结构化字段。`presentationMeta` 是唯一保留它们的途径。
+
+**把抓取正文放进 meta，或把结果内容复制进任一视图。** 否决：正文已是结果内容中面向模型的 markdown，把它复制进 meta 或视图的 `content` 字段会为无收益的目的翻倍持久化或投递载荷；不具备 `web` 能力的 UI 回退到既有的结果内容，那是相同的文本。
+
+## Testing
+
+`packages/web/tool-web/tests/tool-web.spec.ts` 覆盖以下内容，满足按文件 100% 的门禁：`searchMetaFromValue`/`fetchMetaFromValue` 投影，含对缺席可选字段的省略，以及抓取 `truncated` 投影在仅输出上限截断正文时、以及在毫无截断时都与 render 脚注一致；`searchMetaFromResult`/`fetchMetaFromResult` 收窄，含一次往返与每种畸形形状的拒绝（非对象、字段类型错误、畸形来源条目）以及空来源列表的接受；`presentSearchResult`/`presentFetchResult` 类型化视图，含从参数派生的 title、无 `content` 副本、truncated 信号、错误结果回退与畸形 meta 回退；以及两次真实注册表执行，断言工具把 meta 投影到 `result.meta` 上，其注册的 `presentResult` 推导出 `card: 'web'` 视图。
+
+## Related
+
+- [标签化的工具调用渲染意图联合类型](../architecture/2026-07-02-tool-render-intent-union.md) —— 本卡片以 `web` 分支扩展的 `card` 标签词汇表。
+- [Web terminal card](2026-07-28-web-terminal-card.md) —— 把 bash `terminal` 渲染意图带到浏览器的先例；本分支的 web 前端消费者是它的对应物，推迟到后续 PR。