Merge remote-tracking branch 'origin/master' into worktree/composer-scroll-sync

.agents/notes/implemented/feature/2026-07-30-web-read-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-read-card.md
+2026-07-30-web-read-card.md: 1fb3d61a113d26f6daf023fc791f3638055b5be0
+2026-07-30-web-read-card.zh.md: 946bcca95bcc9bb50beb1ef22e77e4a21728b538

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

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+# Agent Note: Read card — the read tool's structured line window reaches the client
+
+Status: implemented
+
+English | [中文](2026-07-30-web-read-card.zh.md)
+
+## Problem
+
+The `read` tool returns a canonical output object `{ path, offset, lines: [{ number, text }], totalLines }`, but its presentation collapsed that structure. `presentCall` declared a `GenericCallView` (`kind: 'read'`, a follow-along location) and `presentResult` returned a `GenericResultView` whose only content was the model-facing text with its `<path>…</path><type>file</type><content>…</content>` envelope stripped. A UI receiving that view saw one flattened text block: the line numbers were baked into the text as `N: ` prefixes, the file's language was unknown, and `totalLines` was gone. There was no way for a capable client to render a read the way it renders a diff — a line-numbered, syntax-highlighted code view with the line-number gutter separate from the content.
+
+The structured data cannot be recovered downstream. A tool result on the wire carries only the model-facing `ContentBlock[]` (the rendered text) plus an opaque `meta`; the canonical output object stays in the tool and never reaches the client or the session log. So a client that wants the line array, the total, and a language hint cannot parse them back out of the `N: text` text — the tool has to project them onto a channel that persists.
+
+## Decision
+
+Add a fourth `card` tag, `read`, to the [render-intent union](../architecture/2026-07-02-tool-render-intent-union.md) — result-side only. `ToolResultView` gains `ReadResultView { card: 'read'; title?; path; lines: ReadFileLine[]; totalLines; lang?; content? }`; `ReadFileLine { number; text }` is the shared line unit. `ToolCallView` is untouched: the pending state stays a `GenericCallView` (`kind: 'read'`) because a call carries no file content until `execute` returns, so there is nothing structured to show at call time. This diverges from the bash terminal card, which tags both sides — a terminal call already carries its command and cwd at call time, a read call carries neither content nor total, so tagging the call side would add an empty variant.
+
+The read tool projects the structured window through `output.presentationMeta`, the same persisted channel write/edit use for their applied-diff hunks ([canonical tool output contract](../architecture/2026-07-20-canonical-tool-output-contract.md)). `presentationMeta` runs once for a top-level surface call, returns `{ path, offset, lines, totalLines, lang? }` as JSON the session validates and stores on the result's `meta`, and `presentResult` narrows that meta back into the `ReadResultView` on both live and replay paths. `offset` (the 1-based first line the window requested) rides along because a byte cap below the first selected line yields an empty `lines` array with a positive `totalLines`; without the persisted `offset` a replayed card of such a window could not report where it starts or where a continuation resumes, and the last-line and re-parse fallbacks are both lossy. Without this channel the line array and total would be unreachable: the raw output object is not on the wire, and re-parsing the `N: text` text is lossy and fragile against the truncation footer.
+
+`presentResult` returns `undefined` — the generic fallback — whenever the meta is absent or malformed (`readMetaFromMeta` narrows it defensively, so a replay of an older logged result never throws), whenever the result is an error, and whenever the single text block is not the read envelope. A pre-card logged result — a valid read envelope with no persisted `meta`, recorded before this card existed — takes that same `undefined` path deliberately: the client falls back to the raw `result.content`, so it shows the enveloped `<path>/<type>/<content>` text rather than the envelope-stripped generic card the old presenter returned. This is the accepted degradation under the [pre-release stance](../../../../AGENTS.md#pre-release-stance-foundation-over-blast-radius): reject the old on-disk format rather than add an envelope-stripping compatibility branch, since this PR re-records every published fixture and the session format promises no backward compatibility. On the success path `presentResult` carries `content` (the envelope-stripped text) alongside the structured fields, so a UI without the read capability, including the current TUI, renders the file text through the generic/default card arm exactly as before. The TUI's `renderBody` switch (`packages/ui/tui/src/components/transcript.ts`) is not `assertNever`-exhaustive: `terminal` and `diff` have arms and everything else falls through to the generic arm, which reads `view.content`. That default arm alone was not enough: `render()` sets `genericContent` — and with it the dim-Markdown `dimBody` treatment — on a separate gate that was `card === 'generic'` only, so a `read` card would have kept the text but lost its dim styling. The gate now admits `card: 'read'` too, taking `content` down the same dim-Markdown path, so a read renders in the TUI exactly as it did before the read card existed. Beyond that one gate the TUI needs no read-specific code.
+
+### Language hint derivation
+
+`langFromPath` (in `read-render.ts`) maps a file extension to a syntax-highlighting language id through a small fixed table (`LANG_BY_EXTENSION`) covering common source, config, and markup extensions. It reads the extension after the last path segment and last dot, is case-insensitive, and returns `undefined` for a dotfile (`.gitignore`), an extensionless name (`/etc/hosts`), a trailing dot, and any unknown extension — the card then omits `lang` and a UI renders plain text. The table is not a tunable: it is a display hint a UI may ignore, not a deployment-varying choice, and an unknown extension degrades to plain text rather than failing. It is deliberately small rather than an exhaustive language registry; extending it is a one-line table addition.
+
+## Alternatives considered
+
+**Re-parse the `N: text` model-facing text in `presentResult`.** Rejected: the structured line array would have to be reconstructed by splitting each line on the first `: `, which is ambiguous (a line whose own text contains `: `), loses the exact `totalLines` (the footer only states it in some branches), and breaks the moment the render format changes. `presentationMeta` carries the already-structured data with no re-parse.
+
+**Tag the call side too (`ReadCallView`), mirroring the terminal card's both-sides symmetry.** Rejected: a read call has no content, no line array, and no total until it executes — a call-side read card would be an empty variant duplicating what `GenericCallView` (`kind: 'read'`, follow-along location) already expresses. The terminal card tags both sides because a terminal call genuinely carries call-time data (command, cwd); a read call does not.
+
+**Put the structured window in a new service or a side channel instead of `meta`.** Rejected: `meta` is the established persisted presentation channel (write/edit's applied diffs ride it), it replays for free with the session log, and it needs no new plumbing. A service would reinvent persistence and replay that the event log already provides.
+
+**A merge-extensible union instead of a closed tag.** Rejected for the same reason the [render-intent union](../architecture/2026-07-02-tool-render-intent-union.md) closed: a new card needs consuming code to render it, so a variant a consumer silently drops is worse than a compile error. Adding `read` to the closed union is the sanctioned way to extend it — each consumer that switches on `card` keeps compiling because the new member falls through its generic default, and a consumer that wants the rich view adds its own arm.
+
+## Consequences
+
+`ToolResultView` has a fourth member. Every consumer that switches on `card` keeps compiling: the TUI and the current Web client route an unknown card to their generic path, and the read card carries `content` so that path shows the file text. The Web frontend that renders the line-numbered, syntax-highlighted view from `lines`/`lang`/`totalLines` is a separate follow-up PR; this PR is the backend that makes the data reachable. Until that lands, a read renders exactly as it did before (the generic text card) everywhere.
+
+The read tool now computes `presentationMeta` for every top-level read, a small per-call projection (a `lines.map` and one `langFromPath` call) on data already in hand. The meta is persisted with the session log, so a read result is slightly larger on disk — the line array it already rendered as text, now also structured.
+
+## Testing
+
+`packages/fs/tool-fs/tests/read-render.spec.ts` unit-tests `langFromPath` (known extensions case-insensitively, extension read after the last segment and last dot, and the `undefined` cases: dotfile, extensionless, trailing dot, unknown) and `readMetaFromMeta` (a well-formed narrow with and without `lang`, and every rejection: non-object, array, missing or wrong-typed `path`/`totalLines`/`lines`, a malformed line entry, a non-string `lang`, and — because the function narrows the opaque persisted `meta` boundary — the semantically invalid paths a well-typed replayed JSON can still carry: an `offset` that is not a 1-based integer, a first line `number` below `offset`, a line `number` that is not a 1-based integer (`0`, `1.5`, `NaN`, `Infinity`), a `totalLines` that is not a non-negative integer (`-1`, `1.5`, `NaN`), and lines whose numbers duplicate, decrease, or exceed `totalLines`; it also narrows an empty window at a positive `offset` (a byte cap below the first selected line). `packages/fs/tool-fs/tests/tools.spec.ts` pins the tool wiring: `execute` attaches the structured window (with and without a `lang` hint) as `meta`, `presentResult` narrows it into a `card: 'read'` view carrying the envelope-stripped `content`, and the decline paths (error result, non-single-text content, malformed envelope with valid meta, and valid envelope with absent or malformed meta) all fall back to `undefined`. Both changed source files hold per-file 100% coverage. This PR carries the snapshot evidence for the persisted meta and the extended union, not for a new rendered view: the re-recorded ACP session fixtures (`fs-read`, `fs-read-window`, `fs-edit`, `fs-policy-reject`, `fs-write-overwrite`, `parallel-tool-calls`, `workspace-context`, `workspace-edit`) pin the persisted read `meta` (with `{{cwd}}`-tokenized paths), and `cordis-inspect-jsdoc` pins the four-member `ToolResultView` union. The keyless snapshot and assembled-application transcript for the rendered read card belong to the follow-up Web PR that consumes the view, since this PR adds no new product-user-visible rendering — the TUI routes the read card through its existing generic dim-Markdown fallback (`transcript.ts` treats `card: 'read'` like `card: 'generic'`), so its output is unchanged. The `apps/cli` `parallel-file-reads` terminal golden (`apps/cli/tests/snapshots/parallel-file-reads/terminal.expected.txt`) pins exactly that: a real replay executes the read tool, renders it through the new `card: 'read'` gate, and the golden's dim-Markdown rows are byte-for-byte what a generic read produced before this card existed.
+
+## 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 `read` result arm.
+- [Canonical tool output contract](../architecture/2026-07-20-canonical-tool-output-contract.md) — owns the `presentationMeta` persisted channel this projects the read window onto.
+- [Web terminal card](2026-07-28-web-terminal-card.md) — the precedent for a client consuming a structured card; the read card follows the same producer pattern, result-side only.

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

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+# Agent Note: Read card — the read tool's structured line window reaches the client
+
+Status: implemented
+
+[English](2026-07-30-web-read-card.md) | 中文
+
+## Problem
+
+`read` 工具返回规范化输出对象 `{ path, offset, lines: [{ number, text }], totalLines }`，但它的展示层把这个结构压平了。`presentCall` 声明为 `GenericCallView`（`kind: 'read'`，一个跟随定位），`presentResult` 返回 `GenericResultView`，其唯一内容是剥掉 `<path>…</path><type>file</type><content>…</content>` 信封后的面向模型文本。收到该视图的 UI 只看到一个压平的文本块：行号以 `N: ` 前缀烘焙进文本、文件语言未知、`totalLines` 丢失。capable 客户端无法像渲染 diff 那样渲染一次 read——即带行号、语法高亮、行号槽与内容分离的代码视图。
+
+结构化数据在下游无法恢复。线上（wire）的工具结果只携带面向模型的 `ContentBlock[]`（已渲染文本）加上一个不透明的 `meta`；规范化输出对象留在工具内，从不到达客户端或会话日志。因此想要行数组、总数和语言提示的客户端无法从 `N: text` 文本里解析回它们——工具必须把它们投影到一个会持久化的通道上。
+
+## Decision
+
+给[渲染意图 union](../architecture/2026-07-02-tool-render-intent-union.md) 新增第四个 `card` 标签 `read`——仅在结果侧。`ToolResultView` 增加 `ReadResultView { card: 'read'; title?; path; lines: ReadFileLine[]; totalLines; lang?; content? }`；`ReadFileLine { number; text }` 是共享的行单元。`ToolCallView` 不动：待定状态仍是 `GenericCallView`（`kind: 'read'`），因为一次调用在 `execute` 返回前不携带文件内容，调用时没有可展示的结构。这与 bash 终端 card 不同——终端 card 两侧都打标签，因为终端调用在调用时已携带命令和 cwd，而 read 调用既无内容也无总数，给调用侧打标签只会新增一个空变体。
+
+read 工具通过 `output.presentationMeta` 投影结构化窗口，这与 write/edit 用来投影其应用 diff hunk 的持久化通道相同（[规范化工具输出契约](../architecture/2026-07-20-canonical-tool-output-contract.md)）。`presentationMeta` 对一次顶层 surface 调用运行一次，返回 `{ path, offset, lines, totalLines, lang? }` 作为会话校验并存储在结果 `meta` 上的 JSON，`presentResult` 在 live 和回放路径上都把该 meta 收窄回 `ReadResultView`。`offset`（窗口请求的 1-based 起始行）一并携带，是因为当字节上限低于首个选中行时，窗口会返回空的 `lines` 数组而 `totalLines` 为正；没有持久化的 `offset`，这类窗口的回放 card 就无法报告它从哪行开始、或续读应从哪行继续，而末行推断与文本重解析两种兜底都有损。没有这个通道，行数组和总数就无法触及：原始输出对象不在线上，而重新解析 `N: text` 文本既有损又对截断脚注脆弱。
+
+`presentResult` 在以下情况返回 `undefined`——即 generic 回退：meta 缺失或畸形（`readMetaFromMeta` 防御性收窄它，因此回放旧的已记录结果永不抛错）、结果是错误、以及单个文本块不是 read 信封。本 card 出现之前记录的结果——信封合法但无持久化 `meta`——有意走同一条 `undefined` 路径：客户端回退到原始 `result.content`，因此显示带 `<path>/<type>/<content>` 信封的原文，而非旧展示器返回的剥信封 generic card。这是 [pre-release 立场](../../../../AGENTS.md#pre-release-stance-foundation-over-blast-radius)下接受的降级：拒绝旧的磁盘格式，而非加一个剥信封的兼容分支——本 PR 已重录全部已发布 fixtures，且 session 格式不承诺向后兼容。在成功路径上，`presentResult` 在结构化字段之外携带 `content`（剥信封后的文本），因此不具备 read 能力的 UI（包括当前的 TUI）通过 generic/default card 分支渲染文件文本，与之前完全一致。TUI 的 `renderBody` switch（`packages/ui/tui/src/components/transcript.ts`）不是 `assertNever` 穷尽的：`terminal` 和 `diff` 有分支，其余都落入 generic 分支，该分支读取 `view.content`。仅有该默认分支还不够：`render()` 在一个独立门控上设置 `genericContent`（连同 dim-Markdown 的 `dimBody` 处理），该门控原先只判 `card === 'generic'`，因此 `read` card 虽保留文本却会丢失 dim 样式。现在该门控也接纳 `card: 'read'`，让 `content` 走同一条 dim-Markdown 路径，因此 read 在 TUI 中的渲染与 read card 出现之前完全一致。除这一处门控外，TUI 无需 read 专属代码。
+
+### 语言提示推导
+
+`langFromPath`（在 `read-render.ts` 中）通过一张固定小表（`LANG_BY_EXTENSION`，覆盖常见源码、配置、标记扩展名）把文件扩展名映射到语法高亮语言 id。它读取最后一个路径段与最后一个点之后的扩展名，大小写不敏感，并对以下情况返回 `undefined`：dotfile（`.gitignore`）、无扩展名（`/etc/hosts`）、结尾的点、以及任何未知扩展名——此时 card 省略 `lang`，UI 渲染纯文本。该表不是可调项（tunable）：它是 UI 可忽略的展示提示，而非随部署变化的选择，未知扩展名降级为纯文本而非失败。它有意保持小规模而非穷尽的语言注册表；扩展它是一行表项新增。
+
+## Alternatives considered
+
+**在 `presentResult` 中重新解析 `N: text` 面向模型文本。** 已否决：结构化行数组将不得不通过按第一个 `: ` 切分每行来重建，这既有歧义（某行文本自身含 `: `），又丢失精确的 `totalLines`（脚注只在部分分支中陈述它），并在渲染格式变化时立即失效。`presentationMeta` 携带已经结构化的数据，无需重新解析。
+
+**调用侧也打标签（`ReadCallView`），镜像终端 card 的两侧对称。** 已否决：read 调用在执行前没有内容、没有行数组、没有总数——调用侧 read card 会是一个空变体，重复 `GenericCallView`（`kind: 'read'`，跟随定位）已经表达的东西。终端 card 两侧都打标签是因为终端调用确实携带调用时数据（命令、cwd）；read 调用没有。
+
+**把结构化窗口放进新服务或旁路通道而非 `meta`。** 已否决：`meta` 是既有的持久化展示通道（write/edit 的应用 diff 就搭它），它随会话日志免费回放，无需新接线。服务会重新发明事件日志已提供的持久化与回放。
+
+**用 merge-extensible union 而非封闭标签。** 出于[渲染意图 union](../architecture/2026-07-02-tool-render-intent-union.md) 封闭的相同理由否决：新 card 需要消费代码来渲染它，因此被消费者静默丢弃的变体比编译错误更糟。把 `read` 加入封闭 union 是扩展它的许可方式——每个在 `card` 上 switch 的消费者都继续编译，因为新成员落入其 generic default，而想要富视图的消费者新增自己的分支。
+
+## Consequences
+
+`ToolResultView` 多了第四个成员。每个在 `card` 上 switch 的消费者都继续编译：TUI 和当前 Web 客户端把未知 card 路由到其 generic 路径，而 read card 携带 `content` 使该路径显示文件文本。从 `lines`/`lang`/`totalLines` 渲染带行号、语法高亮视图的 Web 前端是单独的后续 PR；本 PR 是让数据可触及的后端。在它落地前，read 在各处的渲染与之前完全一致（generic 文本 card）。
+
+read 工具现在为每次顶层 read 计算 `presentationMeta`，这是对已在手数据的一次小投影（一次 `lines.map` 和一次 `langFromPath` 调用）。meta 随会话日志持久化，因此 read 结果在磁盘上略大——它已渲染为文本的行数组，现在也以结构化形式存在。
+
+## Testing
+
+`packages/fs/tool-fs/tests/read-render.spec.ts` 单测 `langFromPath`（已知扩展名的大小写不敏感、扩展名在最后一段与最后一个点之后读取、以及 `undefined` 各情况：dotfile、无扩展名、结尾的点、未知）与 `readMetaFromMeta`（含与不含 `lang` 的良构收窄，以及每种拒绝：非对象、数组、缺失或类型错误的 `path`/`totalLines`/`lines`、畸形行项、非字符串 `lang`，以及——因为该函数收窄持久化的 opaque `meta` 边界——良构类型的回放 JSON 仍可能携带的语义无效路径：不是 1-based 整数的 `offset`、小于 `offset` 的首行 `number`、不是 1-based 整数的行 `number`（`0`、`1.5`、`NaN`、`Infinity`）、不是非负整数的 `totalLines`（`-1`、`1.5`、`NaN`）、以及行号重复、递减或超过 `totalLines` 的情况；并且收窄正 `offset` 处的空窗口（字节上限低于首个选中行））。`packages/fs/tool-fs/tests/tools.spec.ts` 固定工具接线：`execute` 把结构化窗口（含与不含 `lang` 提示）作为 `meta` 附上、`presentResult` 把它收窄为携带剥信封 `content` 的 `card: 'read'` 视图、以及各拒绝路径（错误结果、非单文本内容、meta 有效但信封畸形、信封有效但 meta 缺失或畸形）都回退到 `undefined`。两个改动的源文件保持逐文件 100% 覆盖率。本 PR 携带的是持久化 meta 与扩展后联合类型的快照证据，而非新渲染视图的证据：重录的 ACP session fixtures（`fs-read`、`fs-read-window`、`fs-edit`、`fs-policy-reject`、`fs-write-overwrite`、`parallel-tool-calls`、`workspace-context`、`workspace-edit`）钉住持久化的读取 `meta`（含 `{{cwd}}` 令牌化路径），`cordis-inspect-jsdoc` 钉住四成员的 `ToolResultView` 联合类型。已渲染读取 card 的 keyless 快照与组装应用 transcript 属于消费该视图的后续 Web PR，因为本 PR 不新增任何面向产品用户可见的渲染——TUI 通过其现有的通用 dim-Markdown 回退路由读取 card（`transcript.ts` 把 `card: 'read'` 当作 `card: 'generic'` 处理），因此其输出保持不变。`apps/cli` 的 `parallel-file-reads` 终端 golden（`apps/cli/tests/snapshots/parallel-file-reads/terminal.expected.txt`）正钉住这一点：一次真实回放执行 read 工具、经新的 `card: 'read'` 门渲染，golden 的 dim-Markdown 行与本 card 出现前 generic read 所产出的逐字节一致。
+
+## Related
+
+- [Tagged render-intent union for tool-call presentation](../architecture/2026-07-02-tool-render-intent-union.md) —— 本 Note 以 `read` 结果分支扩展的 `card` 标签词汇。
+- [Canonical tool output contract](../architecture/2026-07-20-canonical-tool-output-contract.md) —— 拥有本 Note 用来投影 read 窗口的 `presentationMeta` 持久化通道。
+- [Web terminal card](2026-07-28-web-terminal-card.md) —— 客户端消费结构化 card 的先例；read card 遵循相同的生产者模式，仅结果侧。