round 1: project the web transcript from append-origin events

Replace the surface-ordered fold with a log-ordered human transcript:
append-origin surface events at their own log positions plus one marker per
landed compaction checkpoint. Command folding, the tool-call index, and the
rev-keyed memo carry over unchanged.

Removes foldDegraded, the padding sentinels, baseSeq, and degradedSeqs() --
they existed only to satisfy the core fold's seq === index assertion. That
also closes the pagination hole A1 exposed: a page can carry a checkpoint
whose shadowed range fell outside the window, and nothing resolves
surfaceOp.start anymore.

.agents/notes/implemented/architecture/2026-07-19-gui-web-client-architecture.i18n.yaml

@@ -1,6 +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
-2026-07-19-gui-web-client-architecture.md: cfc2a7e62358e6282148b2d024ef3b162a903642
-2026-07-19-gui-web-client-architecture.zh.md: b5b082c25f664cfcb0ddd3fcc6c4cd3d58472218
+#   pnpm run verify-translation-pairing --write .agents/notes/implemented/architecture/2026-07-19-gui-web-client-architecture.md
+2026-07-19-gui-web-client-architecture.md: abe28b00638b4f01c7a50efe9ece5148e959a5ee
+2026-07-19-gui-web-client-architecture.zh.md: 560015191fd8d99e2983a19d0b23aeb4dedff837

.agents/notes/implemented/architecture/2026-07-19-gui-web-client-architecture.md

@@ -50,7 +50,7 @@ There is no registration model besides slots — the former view and tool rings
 
 ## The data object layer (`packages/client/runtime/src/client/sessions/`)
 
-Frames enter, snapshots exit, the fold sits between — React-free (zero React imports, grep-assertable):
+Frames enter, snapshots exit, the projection sits between — React-free (zero React imports, grep-assertable):
 
 ```
 mux/host 帧（ConnectionController 泵入，sinks 注入）
@@ -62,17 +62,17 @@ SessionManager.handleMuxEnvelope / handleHostEnvelope
 Session.handleMuxEnvelope ──► events 窗口（seq 连续升序）
         │                        │ 定稿事件            │ chunk
         │                        ▼                    ▼
-        │                   FoldAdapter        PartialAccumulator
+        │                TranscriptAdapter     PartialAccumulator
         │                  （→ nodes）          （→ partial）
         ▼
 Notifier 微任务合批 ──► ConversationSnapshot 缓存 ──uSES──► 组件
 ```
 
-- **Session** (session.ts): lazily built, resident — once created it keeps eating frames in the background, so switching away and back renders instantly. Operations: `prompt`/`cancel` (RPC passthrough; failures land in the snapshot's `promptError`), `open` (pull the tail history page, idempotent), `loadOlder` (upward paging, reentry-guarded), `resync` (reconnect = clear the window and rerun open). Subscription: `subscribe`/`getSnapshot` (always the cached reference) — `implements ObservableSnapshot<ConversationSnapshot>`, with `useSelector = bindSnapshotSelector(this)` attached at construction, so a Session is directly a uSES source. Frame dispatch is one switch: `session/event` frames dedup by seq (the only dedup key), buffer while open is in flight, otherwise append + incremental fold; open/stitch merges the live buffer by seq and backfills once if `subscribed.lastSeq` outruns the window tail.
-- **ConversationSnapshot** (conversation.ts): the immutable snapshot contract — `nodes` (folded, surface-ordered), `partial`, `runningCalls`, `pending`, `running`, `removed`, `openState`, `hasMore`, `promptError` and kin. **Reference discipline** (the premise of memo and uSES): the top-level object is fresh on every change; the nodes array is rebuilt but element references come from the cache; unchanged substructures reuse the previous snapshot's references.
+- **Session** (session.ts): lazily built, resident — once created it keeps eating frames in the background, so switching away and back renders instantly. Operations: `prompt`/`cancel` (RPC passthrough; failures land in the snapshot's `promptError`), `open` (pull the tail history page, idempotent), `loadOlder` (upward paging, reentry-guarded), `resync` (reconnect = clear the window and rerun open). Subscription: `subscribe`/`getSnapshot` (always the cached reference) — `implements ObservableSnapshot<ConversationSnapshot>`, with `useSelector = bindSnapshotSelector(this)` attached at construction, so a Session is directly a uSES source. Frame dispatch is one switch: `session/event` frames dedup by seq (the only dedup key), buffer while open is in flight, otherwise append + incremental projection; open/stitch merges the live buffer by seq and backfills once if `subscribed.lastSeq` outruns the window tail.
+- **ConversationSnapshot** (conversation.ts): the immutable snapshot contract — `nodes` (the human transcript, log-ordered), `partial`, `runningCalls`, `pending`, `running`, `removed`, `openState`, `hasMore`, `promptError` and kin. **Reference discipline** (the premise of memo and uSES): the top-level object is fresh on every change; the nodes array is rebuilt but element references come from the cache; unchanged substructures reuse the previous snapshot's references.
 - **SessionManager** (manager.ts): instance cluster + frame entry + the session list. sessionId-bearing frames go only to existing instances (a mux broadcast must not instantiate every session); approval/question `requested` frames are the exception — they never land in history, so they buffer in `pendingBuffers` and replay on instantiation.
 - **Notifier** (notifier.ts): two channels chosen by change source. `markDirty()` (default; frame-driven changes always) batches per microtask — N changes, one notification, one re-render; the flush rebuilds the snapshot cache before notifying. `notifyNow()` (only direct echoes of user gestures) rebuilds and notifies in the same tick — controlled inputs roll the DOM back and jump the caret if their echo defers to a microtask. Frame-driven code using notifyNow collapses batching back to per-frame renders; banned.
-- **FoldAdapter / PartialAccumulator**: the fold reuses the core SurfaceManager (`@deepseek-ai/dsh-session/surface`), padding sentinel events so a paged window starting at seq > 0 satisfies the core's `seq === index` assertion; a cross-window replace degrades to a tolerant linear scan and sets `foldDegraded`. Chunks stay out of the fold entirely (O(1) skip): the accumulator folds StreamChunks into `AssistantBlock[]`, a delta swapping only that block's reference, and the finalizing message discards the accumulator in the same batch (no flicker on promotion). Cost model: one chunk = one string concatenation + a dirty mark; an unsubscribed Session under a frame storm costs only the mark.
+- **TranscriptAdapter / PartialAccumulator**: the transcript is the append-origin surface projected in log order (`isAppendSurfaceEvent` from `@deepseek-ai/dsh-session/surface`) plus one marker per landed compaction checkpoint — never the model surface, which shadows replaced ranges and would erase conversation the reader already saw. Node order is seq-monotonic by construction, so there is no core `seq === index` assertion to satisfy and no degradation branch. Chunks contribute no node (O(1) skip): the accumulator folds StreamChunks into `AssistantBlock[]`, a delta swapping only that block's reference, and the finalizing message discards the accumulator in the same batch (no flicker on promotion). Cost model: one chunk = one string concatenation + a dirty mark; an unsubscribed Session under a frame storm costs only the mark.
 - **ConnectionController** (in `packages/client/connection`): opens the mux/host streams, pumps with for-await, reconnects with exponential backoff (500ms doubling to 10s, jitter, unlimited) behind a generation fence; sinks are injected one-way (the Controller does not know Session). Reconnect = rebuild: `onConnected` → list refresh + per-open-session resync. The object layer faces only `IApiClient`; the Web carriage (HTTP POST for the two client→server quadrants, SSE for the two server→client) and the client class family are the layering RFC's territory.
 
 ## The React face (`packages/client/web-react`)

.agents/notes/implemented/architecture/2026-07-19-gui-web-client-architecture.zh.md

@@ -62,17 +62,17 @@ SessionManager.handleMuxEnvelope / handleHostEnvelope
 Session.handleMuxEnvelope ──► events 窗口（seq 连续升序）
         │                        │ 定稿事件            │ chunk
         │                        ▼                    ▼
-        │                   FoldAdapter        PartialAccumulator
+        │                TranscriptAdapter     PartialAccumulator
         │                  （→ nodes）          （→ partial）
         ▼
 Notifier 微任务合批 ──► ConversationSnapshot 缓存 ──uSES──► 组件
 ```
 
 - **Session**（session.ts）：懒建、常驻——建成后在后台持续吃帧，切走切回秒显。操作面：`prompt`/`cancel`（RPC 透传；失败落进快照的 `promptError`）、`open`（拉尾页 history，幂等）、`loadOlder`（向上翻页，防重入）、`resync`（重连 = 清窗口重跑 open）。订阅面：`subscribe`/`getSnapshot`（恒返缓存引用）——`implements ObservableSnapshot<ConversationSnapshot>`，构造时挂 `useSelector = bindSnapshotSelector(this)`，Session 本身就是 uSES 源。帧分发是一个 switch：`session/event` 帧按 seq 去重（唯一去重键），open 在途时缓冲，否则追加 + 增量 fold；open/缝合按 seq 合并 live 缓冲并去重，`subscribed.lastSeq` 超出窗口尾则回补一次。
-- **ConversationSnapshot**（conversation.ts）：不可变快照契约——`nodes`（fold 产物，surface 序）、`partial`、`runningCalls`、`pending`、`running`、`removed`、`openState`、`hasMore`、`promptError` 等。**引用纪律**（memo 与 uSES 的前提）：顶层对象每变必新；nodes 数组重建但元素引用来自缓存；未变的子结构复用上一快照的引用。
+- **ConversationSnapshot**（conversation.ts）：不可变快照契约——`nodes`（人类对话记录，日志序）、`partial`、`runningCalls`、`pending`、`running`、`removed`、`openState`、`hasMore`、`promptError` 等。**引用纪律**（memo 与 uSES 的前提）：顶层对象每变必新；nodes 数组重建但元素引用来自缓存；未变的子结构复用上一快照的引用。
 - **SessionManager**（manager.ts）：实例簇 + 帧总入口 + 会话列表。带 sessionId 的帧只投已存在实例（mux 广播不得把每个会话都实例化）；例外是审批/问答 `requested` 帧——它们不落 history、open 无法回补，故缓冲进 `pendingBuffers`，实例化时回放。
 - **Notifier**（notifier.ts）：两条通知通道，按变更来源取用。`markDirty()`（默认；帧驱动一律用它）按微任务合批——N 次变更、一次通知、一次重渲染；flush 先重建快照缓存再通知。`notifyNow()`（仅用户手势的直接回响）同 tick 重建并通知——受控输入的回响若延到微任务，DOM 会回滚、光标跳尾。帧驱动代码用 notifyNow 会让合批塌回逐帧渲染；禁。
-- **FoldAdapter / PartialAccumulator**：fold 复用核心 SurfaceManager（`@deepseek-ai/dsh-session/surface`），垫哨兵事件使 seq > 0 起头的分页窗口满足核心的 `seq === index` 断言；跨窗口 replace 时降级为容错线性扫描并置 `foldDegraded`。分片完全不进 fold（O(1) 跳过）：累积器把 StreamChunk 折叠成 `AssistantBlock[]`，一次增量只换该块引用；定稿消息到达即在同一批内弃掉累积器（提升无闪烁）。成本模型：一个分片 = 一次字符串拼接 + 一个脏标记；帧风暴下未订阅的 Session 只花那个标记。
+- **TranscriptAdapter / PartialAccumulator**：对话记录是按日志顺序投影的 append 来源 surface（`@deepseek-ai/dsh-session/surface` 的 `isAppendSurfaceEvent`），外加每次落地的压缩检查点一个标记——绝不用模型 surface，后者遮蔽被替换的范围，会抹掉读者已经看过的对话。节点顺序天然按 seq 单调，因此既无核心 `seq === index` 断言需要满足，也没有降级分支。分片不贡献任何节点（O(1) 跳过）：累积器把 StreamChunk 折叠成 `AssistantBlock[]`，一次增量只换该块引用；定稿消息到达即在同一批内弃掉累积器（提升无闪烁）。成本模型：一个分片 = 一次字符串拼接 + 一个脏标记；帧风暴下未订阅的 Session 只花那个标记。
 - **ConnectionController**（在 `packages/client/connection`）：开 mux/host 双流、for-await 泵入，代际围栏之内指数退避重连（500ms 翻倍至 10s 封顶、抖动、无限重试）；sinks 单向注入（Controller 不认识 Session）。重连 = 重建：`onConnected` → 列表刷新 + 各已打开会话 resync。对象层只面向 `IApiClient`；Web 承载（HTTP POST 载两个 client→server 象限、SSE 载两个 server→client 象限）与客户端类族归分层 RFC 属地。
 
 ## React 面（`packages/client/web-react`）

.agents/notes/implemented/bug-fix/2026-07-29-human-transcript-append-origin.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write .agents/notes/implemented/bug-fix/2026-07-29-human-transcript-append-origin.md
-2026-07-29-human-transcript-append-origin.md: a296b93d538d9c28bd61ee8fd0530863b4bfd878
-2026-07-29-human-transcript-append-origin.zh.md: 96e0cd1038fe8904dfd4c1eceaae9b25339c5dca
+2026-07-29-human-transcript-append-origin.md: dcc4a786c6f1926f06dce03124ec1d8ca805d7ae
+2026-07-29-human-transcript-append-origin.zh.md: 0fefc52afa52e99cdec2bcea1a86b9c28711dd67

.agents/notes/implemented/bug-fix/2026-07-29-human-transcript-append-origin.md

@@ -24,9 +24,9 @@ No persisted event, RPC envelope, compaction transaction, or model-visible surfa
 
 ## Deferred
 
-The browser client still builds its conversation from the model surface through `FoldAdapter`, so compaction still collapses web history to a single context row. The same predicate is the fix there, together with an append-order transcript projection and a marker component; that work is a separate change against `packages/client/runtime` and `packages/client/ui-conversation`.
+The browser client is fixed separately, in [the web transcript projection note](2026-07-30-web-transcript-log-ordered-projection.md): it projects the same append-origin transcript in log order and renders a marker component, and it closes the pagination hole this change opened — because `session.history` no longer spends quota on the checkpoint, it never cuts on the checkpoint's provenance group, so a page can carry a checkpoint citing a `surfaceOp.start` outside the window, which the browser's surface fold rejected. That hole predates this change (counting could already run past a checkpoint into the range it shadows), but the old rule accidentally covered the case where the checkpoint was the oldest counted message and pulled the whole shadowed range onto its page.
 
-That work must handle a page whose checkpoint cites a `surfaceOp.start` outside the window: pagination no longer spends quota on the checkpoint, so it never cuts on the checkpoint's provenance group, and `FoldAdapter` pads absent events with a non-surface sentinel — so `SurfaceManager` rejects the range and `nodes()` falls back to `degradedSeqs()` with a logged error. The hole predates this change (counting could already run past a checkpoint into the range it shadows), but the old rule accidentally covered the case where the checkpoint was the oldest counted message and pulled the whole shadowed range onto its page. `degradedSeqs()` — every surface-eligible event in append order — is already close to the transcript projection A2 needs, which is the shape to build deliberately rather than reach as a degradation. Rendering compaction *progress* — a terminal indicator while a compaction runs — needs the bracket-first ordering that the queued manual `/compact` work introduces, and is likewise out of scope here. The marker also carries no scale: the checkpoint's `sourceEventSeqs` already hold the shadowed count, so a count or range would tell a reader how much each row folded. That belongs with progress, where the reader meets the other half of the same information. Whoever takes it should fold the terminal's two replacement branches — replay and the live listener, textually identical and 600 lines apart — into one `renderReplacement(event)` first, so the marker's content has a single home.
+Rendering compaction *progress* — a terminal indicator while a compaction runs — needs the bracket-first ordering that the queued manual `/compact` work introduces, and is out of scope here. The marker also carries no scale: the checkpoint's `sourceEventSeqs` already hold the shadowed count, so a count or range would tell a reader how much each row folded. That belongs with progress, where the reader meets the other half of the same information. Whoever takes it should fold the terminal's two replacement branches — replay and the live listener, textually identical and 600 lines apart — into one `renderReplacement(event)` first, so the marker's content has a single home.
 
 ## Alternatives considered
 

.agents/notes/implemented/bug-fix/2026-07-29-human-transcript-append-origin.zh.md

@@ -24,9 +24,9 @@ Status: implemented
 
 ## Deferred
 
-浏览器客户端仍通过 `FoldAdapter` 从模型 surface 构建会话，因此压缩在 Web 端仍会把历史折叠成一行上下文。那里的修复用的是同一个谓词，另需按追加顺序的记录投影与一个标记组件；该工作是针对 `packages/client/runtime` 与 `packages/client/ui-conversation` 的独立变更。
+浏览器客户端在[Web 记录投影笔记](2026-07-30-web-transcript-log-ordered-projection.md)中单独修复：它按日志顺序投影同一份 append 来源记录并渲染一个标记组件，同时闭合本次变更打开的分页缺口——因为 `session.history` 不再为检查点消耗额度，它永远不会按检查点的溯源分组切分，于是一页可以携带一个引用了窗口之外 `surfaceOp.start` 的检查点，而浏览器的 surface fold 会拒绝该范围。这个缺口早于本次变更（此前计数就可能越过检查点进入它所遮蔽的范围），但旧规则恰好覆盖了这样一种情形：检查点是最旧的被计数消息，其溯源分组把整段被遮蔽的范围一起拉到该页。
 
-该工作必须处理这样一页：其检查点引用的 `surfaceOp.start` 落在窗口之外。分页不再为检查点消耗额度，因此永远不会按检查点的溯源分组切分；而 `FoldAdapter` 会用一个非 surface 的哨兵事件填补缺失事件——于是 `SurfaceManager` 拒绝该范围，`nodes()` 退化为 `degradedSeqs()` 并记录一条错误。这个缺口早于本次变更（此前计数就可能越过检查点进入它所遮蔽的范围），但旧规则恰好覆盖了这样一种情形：检查点是最旧的被计数消息，其溯源分组把整段被遮蔽的范围一起拉到该页。`degradedSeqs()`——按追加顺序的每个 surface 可入事件——已经很接近 A2 所需的记录投影，因此那正是应当刻意构建的形态，而不是作为退化路径被动落到的结果。渲染压缩*进度*——压缩运行期间的终端指示——需要排队式手动 `/compact` 工作引入的“先开括号”顺序，同样不在本次范围内。标记同样不携带规模信息：检查点的 `sourceEventSeqs` 已经包含被遮蔽的数量，因此一个计数或区间可以告诉读者每一行折叠了多少内容。这件事属于进度那一侧，读者正是在那里遇到同一份信息的另一半。接手者应当先把终端里两处替换分支——回放与实时监听器，文本完全相同却相隔 600 行——合并为一个 `renderReplacement(event)`，让标记的内容只有一个归处。
+渲染压缩*进度*——压缩运行期间的终端指示——需要排队式手动 `/compact` 工作引入的“先开括号”顺序，不在本次范围内。标记同样不携带规模信息：检查点的 `sourceEventSeqs` 已经包含被遮蔽的数量，因此一个计数或区间可以告诉读者每一行折叠了多少内容。这件事属于进度那一侧，读者正是在那里遇到同一份信息的另一半。接手者应当先把终端里两处替换分支——回放与实时监听器，文本完全相同却相隔 600 行——合并为一个 `renderReplacement(event)`，让标记的内容只有一个归处。
 
 ## Alternatives considered
 

.agents/notes/implemented/bug-fix/2026-07-30-web-transcript-log-ordered-projection.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-web-transcript-log-ordered-projection.md
+2026-07-30-web-transcript-log-ordered-projection.md: 22e687ebc0a323a28eb554a9ad36749a0b6f3da6
+2026-07-30-web-transcript-log-ordered-projection.zh.md: 97004f7384aed8f9e43b0949b2fcd4b8c185ca65

.agents/notes/implemented/bug-fix/2026-07-30-web-transcript-log-ordered-projection.md

@@ -0,0 +1,66 @@
+# Agent Note: The browser conversation is a log-ordered human transcript
+
+Status: implemented
+
+English | [中文](2026-07-30-web-transcript-log-ordered-projection.zh.md)
+
+## Problem
+
+The browser client built its conversation from the model-visible surface: `FoldAdapter` ran the core `SurfaceManager` over the history window and read `surface.nodes`. A successful compaction replaces a surface range with one checkpoint node, so the moment that replacement landed the web flow collapsed every message it shadowed into a single dim context row — conversation the user had already read. Nothing was lost from the log; the defect was entirely in the projection, and [the terminal and the host gateway were fixed the same way](2026-07-29-human-transcript-append-origin.md) while the browser was left for this change.
+
+Surface order made two further problems structural. It is not seq-ascending after a replacement — `SurfaceManager` splices the high-seq checkpoint into the position of the range it shadows — so log-only nodes merged into that array by numeric seq (slash-command rows, interrupted frozen nodes) could be flushed ahead of the checkpoint and never interleave into the retained tail again. And because pagination no longer spends `maxMessages` quota on replacement copies, a page can now carry a checkpoint whose `surfaceOp.start` lies outside the window; the core fold rejects that range, so `nodes()` fell back to a lenient linear scan behind a `console.error` and published a `foldDegraded` flag describing the failure.
+
+## Decision
+
+`TranscriptAdapter` replaces `FoldAdapter` and never consults surface order. It projects the raw window in log order: every append-origin surface event (`isAppendSurfaceEvent`) at its own log position, plus one `CompactionSummaryNode` marker per landed compaction checkpoint. A landed compaction therefore keeps the conversation it shadowed on the model side, and the marker reports where the model stopped seeing that history instead of erasing it. Model-only replacement copies stay out of the transcript: a pruned `tool/result` and a regenerated `assistant/message` rewrite one node for the model and mark no boundary in the conversation. Everything that must send exactly what the model sees keeps reading the surface; this is the human projection, and the two are now separate on both frontends.
+
+Node order is seq-monotonic by construction, and three things follow. The log-only `command/run` / `command/done` pair folds into `CommandNode`s that splice into an already-monotonic array by seq — no anchors, no reordering. `Session` keeps ownership of interrupted frozen nodes and merges them by their fractional seqs with a plain sort, which is now exactly flow order. And a window whose checkpoint cites a shadowed range outside it has no range to resolve, so the marker renders and nothing is logged.
+
+`foldDegraded` is gone from `ConversationSnapshot`, and with it the padding sentinels, the `baseSeq` arithmetic they needed, and `degradedSeqs()`. They existed only to satisfy the core fold's `seq === index` assertion and to survive its throw; the fold they describe is no longer run. Deleting the flag is part of the fix, not cleanup after it — `degradedSeqs()` was already almost the log-ordered projection, reached after a thrown error instead of intended.
+
+The marker's summary text comes from the checkpoint's own `compact/summary` provenance, never from the framed checkpoint payload, which is an instruction envelope written for the model. A window cut that left the provenance outside makes the row non-expandable rather than empty, the same soft-fall as a call-less tool result, and a later page supplying the provenance resolves the text.
+
+No persisted event, RPC envelope, compaction transaction, or model-visible surface changed, and no migration is required.
+
+## Recognizing a checkpoint: the local literal and its drift trap
+
+Recognition needs all three conditions, as in the terminal: `event.type === 'user/message'`, the compaction seam's checkpoint plugin source, **and** `isReplacementSurfaceEvent(event)`. A plugin-sourced `user/message` that *appends* is injected context — a session-reference card — not a compaction.
+
+The client restates that plugin source as a local literal, because `dsh-compact` is unreachable from `packages/client/runtime`'s program in **both** directions:
+
+- a **value** import fails the client purity gate (`packages/client/tsdown.client.ts`), and `dsh-compact`'s root value-imports cordis, so admitting it would pull `CompactService` into the browser bundle;
+- a **type-only** import fails typecheck. `dsh-compact`'s root reaches `dsh-session`'s root, whose cordis `Context` merge declares the host `sessions: SessionStore` against this program's `sessions: ISessions` — `TS2717`, the one-program-per-side rule in [development.md](../../../../docs/development.md#typescript-project-layout). This was expected to work and does not; `import type` is erased before the *bundler* runs, but not before the *compiler* does, and the collision is a compiler fact.
+
+The drift protection therefore lives in a test, not in a type: `packages/client/runtime/tests/compact-checkpoint-pin.spec.ts` runs in the client **test** program, which carries no such collision, and drives the adapter with a checkpoint built from the canonical `COMPACT_CHECKPOINT_SOURCE` itself. Renaming the seam's plugin fails there instead of silently deleting every compaction marker from the web transcript. `dsh-compact` is a `devDependency` of `dsh-client-runtime` and a reference of `tsconfig.client.json` only — never of a `packages/client/*` package project.
+
+That is a deliberate divergence from the terminal, which value-imports `isCompactCheckpointSource` directly because no gate applies host-side.
+
+## What #835's positional anchors were for, and why they are dissolved rather than lost
+
+The unmerged manual-compaction-queueing branch fixes the same interleaving bug by recording a per-event anchor — the surface tail at append time — and retargeting shadowed anchors onto the checkpoint. That mechanism exists to make positional anchors survive surface **reordering**. The human transcript is never re-ordered, so anchors have nothing to retarget: the precondition is removed, not the fix discarded. The mechanism is absent from this base and is not authored here.
+
+## Alternatives considered
+
+**Add `dsh-compact` to the client `INLINE_SAFE` allowlist** and move the predicate to a cordis-free subpath. Rejected: `INLINE_SAFE` matches on specifier *prefix*, so admitting the package admits its cordis-importing root too; the allowlist is a reviewer promise about client-facing subpaths, not a purity proof. It also needs a new export and a `files` fix, and it would not have helped — the blocking collision turned out to be in the compiler, which an allowlist does not touch.
+
+**A bare shape rule** — any replacement `user/message` is a compaction. Rejected: correct today only because compaction is the sole producer of replacement `user/message`s, with nothing to catch it if that changes. The pinning spec costs one file and removes exactly that risk.
+
+**Tag the checkpoint host-side** through the projection or wire contract. Rejected: most aligned with the "collaborate through cordis services" rule, but the client folds raw `SessionEvent`s today, so it means a wire contract change out of proportion to one pure predicate.
+
+**Move frozen-node ownership into the adapter** (`nodes(extraNodes)`), as the unmerged branch does. Rejected: the interrupted nodes come from the `turn/end` sweep `Session` already runs over the window, and with a seq-monotonic transcript the simple shape is correct — the adapter returns nodes, the session merges frozen ones by seq. Widening the adapter's signature would buy nothing and split the sweep from its product.
+
+**Keep `foldDegraded` as a defensive flag.** Rejected: it described a specific failure of a fold that no longer runs. A flag no consumer can act on, reachable only through a `console.error`, is a false contract.
+
+## Consequences
+
+Compaction no longer erases web history; a session compacted several times shows one marker per landed compaction, in log order, and the same window renders identically live and after a cold resume. The pagination hole is closed by construction rather than defended against, and `ConversationSnapshot` loses a published field, which touched thirteen files.
+
+`ConversationNode` gains an eighth arm, so every exhaustive consumer grew one case: `MessageItem` renders the marker through the new `CompactionItem`, and the trajectory layout widens its no-cell arm so a marker contributes no cell but still advances the duration cursor.
+
+The performance contract is unchanged and now simpler to state: one append materializes one node, an event that changes no node keeps the previous array reference — so a chunk storm costs nothing and `nodes()` is not even recomputed — and unchanged nodes keep their object identity. The window still grows with session length rather than with the surface, which is the trade the fix exists to make; a compaction used to bound the projection for exactly the long sessions compaction serves.
+
+The web e2e scenario now seeds a real compaction transaction over its recorded turn, so the aria golden pins both halves of the fix through the real host and a real browser: the recorded prompt and full tool output are still on screen, and one marker sits after them. The seed recording itself is untouched and stays model-authentic — replay derives the compacted turn from the recording's own surface.
+
+## Deferred
+
+Compaction **progress** — an indicator while a compaction runs — needs the bracket-first ordering the queued manual-compaction work introduces, and stays out of scope here as it did in the terminal. The marker also carries no **scale**: the checkpoint's `sourceEventSeqs` already hold the shadowed count, so a count or range would tell a reader how much each row folded. Both belong together, where the reader meets the two halves of the same information.

.agents/notes/implemented/bug-fix/2026-07-30-web-transcript-log-ordered-projection.zh.md

@@ -0,0 +1,66 @@
+# Agent Note: 浏览器会话是按日志顺序投影的人类对话记录
+
+Status: implemented
+
+[English](2026-07-30-web-transcript-log-ordered-projection.md) | 中文
+
+## Problem
+
+浏览器客户端从模型可见的 surface 构建会话：`FoldAdapter` 在历史窗口上运行核心 `SurfaceManager` 并读取 `surface.nodes`。一次成功的压缩会用一个检查点节点替换一段 surface 范围，因此该替换一落地，Web 流就把它所遮蔽的每条消息折叠成一行灰暗的上下文——那是用户已经读过的对话。日志中什么都没丢失；缺陷完全在投影层，而[终端与宿主历史网关已按同一方式修复](2026-07-29-human-transcript-append-origin.md)，浏览器留给了本次变更。
+
+surface 顺序还让另外两个问题成为结构性的。一次替换之后它并非按 seq 升序——`SurfaceManager` 把高 seq 的检查点拼接到它所遮蔽范围的位置上——因此按数值 seq 归并进该数组的仅日志节点（斜杠命令行、被打断的冻结节点）可能被冲刷到检查点之前，再也无法交错回保留下来的尾部。而且由于分页不再为 replacement 副本消耗 `maxMessages` 额度，一页现在可以携带一个 `surfaceOp.start` 落在窗口之外的检查点；核心 fold 拒绝该范围，于是 `nodes()` 退回到一次宽容的线性扫描、打印一条 `console.error`，并发布一个描述该失败的 `foldDegraded` 标志。
+
+## Decision
+
+`TranscriptAdapter` 取代 `FoldAdapter`，并且从不查询 surface 顺序。它按日志顺序投影原始窗口：每个 append 来源的 surface 事件（`isAppendSurfaceEvent`）落在它自己的日志位置上，外加每次落地的压缩检查点一个 `CompactionSummaryNode` 标记。于是一次落地的压缩会保留它在模型侧遮蔽掉的对话，标记报告模型从哪里开始看不见那段历史，而不是把它抹掉。仅模型可见的 replacement 副本不进入记录：被裁剪的 `tool/result` 和重新生成的 `assistant/message` 只为模型重写一个节点，不在对话中标记任何边界。凡必须发送模型所见内容的一切仍读 surface；这是人类投影，两者现在在两个前端上都已分离。
+
+节点顺序天然按 seq 单调，由此有三个结果。仅日志的 `command/run` / `command/done` 对折叠成 `CommandNode`，按 seq 插入一个本已单调的数组——无锚点，无重排。`Session` 保留被打断的冻结节点的归属，用一次普通排序按其分数 seq 归并，而这现在恰好就是流顺序。检查点所引被遮蔽范围落在窗口之外的窗口没有范围需要解析，因此标记正常渲染且不打印任何日志。
+
+`foldDegraded` 从 `ConversationSnapshot` 消失，随之消失的是哨兵填充、它们所需的 `baseSeq` 算术，以及 `degradedSeqs()`。它们的存在只为满足核心 fold 的 `seq === index` 断言并在其抛错时存活；它们所描述的 fold 已不再运行。删除该标志是修复的一部分，而非修复之后的清理——`degradedSeqs()` 本身已几乎就是按日志顺序的投影，只是作为抛错后的落点而非本意到达。
+
+标记的摘要文本来自检查点自己的 `compact/summary` 溯源，绝不取自成框的检查点载荷——那是为模型撰写的指令信封。窗口切分把溯源留在窗口外时该行不可展开而非空白，与无调用的工具结果同一种软退让；后续补上溯源的分页会解析出文本。
+
+没有任何持久化事件、RPC 信封、压缩事务或模型可见 surface 发生变化，也不需要迁移。
+
+## 识别检查点：本地字面量与它的漂移陷阱
+
+识别需要三个条件同时成立，与终端一致：`event.type === 'user/message'`、压缩缝隙的检查点插件来源，**以及** `isReplacementSurfaceEvent(event)`。一条 append 的插件来源 `user/message` 是注入上下文——跨会话引用卡片——不是压缩。
+
+客户端把该插件来源重述为一个本地字面量，因为 `dsh-compact` 在**两个**方向上都无法从 `packages/client/runtime` 的程序到达：
+
+- **值**导入会失败于客户端纯度门禁（`packages/client/tsdown.client.ts`），而 `dsh-compact` 的根部会值导入 cordis，因此放行它就会把 `CompactService` 拉进浏览器产物；
+- **仅类型**导入会失败于类型检查。`dsh-compact` 的根部会到达 `dsh-session` 的根部，后者的 cordis `Context` 合并声明了宿主侧 `sessions: SessionStore`，与本程序的 `sessions: ISessions` 冲突——`TS2717`，即 [development.md](../../../../docs/development.md#typescript-project-layout) 中每侧一个 program 的规则。这一点原本预期可行，实际不可行：`import type` 在**打包器**运行前被擦除，但不在**编译器**运行前被擦除，而该冲突是编译器事实。
+
+因此漂移保护住在一个测试里，而不是一个类型里：`packages/client/runtime/tests/compact-checkpoint-pin.spec.ts` 运行在客户端**测试**程序中——那里不存在这一冲突——并用由权威 `COMPACT_CHECKPOINT_SOURCE` 本身构造的检查点驱动适配器。重命名缝隙的插件会在那里失败，而不是无声地把每个压缩标记从 Web 记录中删除。`dsh-compact` 只是 `dsh-client-runtime` 的 `devDependency` 以及 `tsconfig.client.json` 的一条引用——绝不是任何 `packages/client/*` 包工程的引用。
+
+这是与终端的一次刻意分歧：终端直接值导入 `isCompactCheckpointSource`，因为宿主侧不适用任何门禁。
+
+## #835 的位置锚点是为什么而存在，以及为什么它是被溶解而非丢失
+
+尚未合并的排队式手动压缩分支用另一种方式修同一个交错缺陷：为每个事件记录一个锚点——追加时的 surface 尾部——并把被遮蔽的锚点重定向到检查点上。该机制的存在是为了让位置锚点在 surface **重排**中存活。人类对话记录永不被重排，因此锚点没有任何东西需要重定向：前提被移除，修复并未被丢弃。该机制在本基线上并不存在，本次也不撰写它。
+
+## Alternatives considered
+
+**把 `dsh-compact` 加入客户端 `INLINE_SAFE` 白名单**，并把谓词搬到一个不含 cordis 的子路径。已拒绝：`INLINE_SAFE` 按标识符*前缀*匹配，因此放行该包也就放行了它那个会导入 cordis 的根部；该白名单是对面向客户端子路径的评审承诺，不是纯度证明。它还需要一个新导出与一处 `files` 修正，而且本来也帮不上忙——真正阻塞的冲突出在编译器，白名单碰不到那里。
+
+**一条纯形状规则**——任何 replacement `user/message` 都是压缩。已拒绝：它今天正确只因为压缩是 replacement `user/message` 的唯一生产者，一旦这点改变便无任何机制能捕获。那个 pin 测试只花一个文件，就精确消除了这一风险。
+
+**在宿主侧给检查点打标**，经投影或线协议。已拒绝：这最贴合“经 cordis 服务协作”的规则，但客户端今天折叠的是原始 `SessionEvent`，因此这意味着一次线协议契约变更——为一个纯谓词付出的代价不成比例。
+
+**把冻结节点的归属移进适配器**（`nodes(extraNodes)`），像那个未合并分支所做的那样。已拒绝：被打断的节点来自 `Session` 已经在窗口上运行的 `turn/end` 清扫，而在按 seq 单调的记录之上，简单形态就是正确的——适配器返回节点，会话按 seq 归并冻结节点。加宽适配器签名什么也换不到，还会把清扫与它的产物拆开。
+
+**把 `foldDegraded` 留作一个防御性标志。** 已拒绝：它描述的是一个已不再运行的 fold 的特定失败。一个消费方无法据以行动、只能通过 `console.error` 到达的标志，是一份虚假契约。
+
+## Consequences
+
+压缩不再抹掉 Web 历史；一个被压缩多次的会话按日志顺序显示每次落地压缩一个标记，而同一窗口在实时与冷恢复之后渲染完全相同。分页缺口是被构造性闭合而非被防御，`ConversationSnapshot` 少了一个已发布字段，这触及十三个文件。
+
+`ConversationNode` 增加第八个分支，因此每个穷尽消费方都多一个分支：`MessageItem` 通过新的 `CompactionItem` 渲染标记，trajectory 布局加宽它的“无单元格”分支，使标记不贡献单元格但仍推进耗时游标。
+
+性能契约未变，且现在更易表述：一次追加物化一个节点，不改变任何节点的事件保持上一次的数组引用——因此分片风暴零成本、`nodes()` 甚至不会重算——未变化的节点保持其对象标识。窗口仍随会话长度而非随 surface 增长，这正是本修复存在所要做的交换；一次压缩过去恰好为压缩所服务的长会话限制了投影规模。
+
+Web e2e 场景现在在它录制的那一轮之上播种一次真实的压缩事务，因此 aria 基准经真实宿主与真实浏览器钉住修复的两半：录制的提问与完整工具输出仍在屏幕上，其后坐着一个标记。录制本身未被触碰、保持模型真实——回放从录制自身的 surface 派生出被压缩的那一轮。
+
+## Deferred
+
+压缩**进度**——压缩运行期间的指示——需要排队式手动压缩工作引入的“先开括号”顺序，与终端一样不在本次范围内。标记同样不携带**规模**信息：检查点的 `sourceEventSeqs` 已经包含被遮蔽的数量，因此一个计数或区间可以告诉读者每一行折叠了多少内容。两者应当放在一起，读者正是在那里遇到同一份信息的两半。

apps/web/tests/seeded-history.e2e.ts

@@ -1,8 +1,8 @@
 // Web e2e scenario: seeded history. A recorded session seeded cold through
 // the REAL persistence API renders purely from the log — the surface nothing
 // else covers: sidebar cold listing, the implicit resume/attach inside the
-// history RPC, history-page tool views, and the client fold of historical
-// events — with ZERO model calls in replay (no replay fixture; a stray stream
+// history RPC, history-page tool views, and the client's log-ordered transcript
+// of historical events — with ZERO model calls in replay (no replay fixture; a stray stream
 // fails loud on the open llm seam). The seed is a recorded fixture under the
 // same record discipline as every other: DSH_SNAPSHOT=record drives the turn
 // live through the composer (real read tool against seeded workspace files)
@@ -27,6 +27,77 @@ const SEED_ID = 'seeded-history-web-e2e'
 
 const PROMPT = 'Use the read tool twice in one assistant message: read a.txt and b.txt. Then reply with the single word DONE and stop.'
 
+/**
+ * Append a complete, valid compaction transaction over the recorded turn's own
+ * surface. The recording stays model-authentic and reusable; replay adds this
+ * deterministic condition before seeding it cold, so the scenario pins the bug
+ * this change fixes — a landed compaction must not erase history the reader
+ * already saw — through the real host and the real browser.
+ * @param raw - the committed seed fixture text.
+ * @returns the fixture with a compacted turn appended.
+ */
+function withCompaction(raw: string): string {
+  const lines = raw.trimEnd().split('\n')
+  const events = lines.slice(1).map(line => JSON.parse(line) as {
+    type: string
+    seq: number
+    time: number
+    surfaceOp?: unknown
+  })
+  const surfaceSeqs = events
+    .filter(event => event.surfaceOp === 'append'
+      && (event.type === 'user/message'
+        || event.type === 'assistant/message'
+        || event.type === 'tool/result'
+        || event.type === 'steering/message'))
+    .map(event => event.seq)
+  const first = surfaceSeqs[0]
+  const last = surfaceSeqs.at(-1)
+  const tail = events.at(-1)
+  if (first === undefined || last === undefined || tail === undefined) {
+    throw new Error('seeded-history compaction requires a non-empty closed surface')
+  }
+  let seq = tail.seq + 1
+  let time = tail.time + 1
+  const at = (event: Record<string, unknown>): string => JSON.stringify({ ...event, seq: seq++, time: time++ })
+  // The checkpoint's provenance names the two events appended before it.
+  const startSeq = seq + 1
+  const summarySeq = seq + 2
+  lines.push(
+    at({ type: 'turn/start', data: { turn: 2, trigger: { kind: 'injection', source: { kind: 'plugin', plugin: 'compact' } } } }),
+    at({ type: 'compact/start', data: { turn: 2 } }),
+    at({
+      type: 'compact/summary',
+      data: {
+        summary: [{
+          type: 'text',
+          text: '## Cold resume compact summary\n\n- The exact summary remains available.',
+        }],
+        shadowedRange: { start: first, end: last },
+        shadowedSeqs: surfaceSeqs,
+        shadowedTokenCount: 10_000,
+        provider: 'snapshot',
+        model: 'snapshot-compactor',
+      },
+    }),
+    at({
+      type: 'user/message',
+      data: {
+        content: [{
+          type: 'text',
+          text: '<context_checkpoint>Model-only compact checkpoint.</context_checkpoint>',
+        }],
+        source: { kind: 'plugin', plugin: 'compact' },
+      },
+      surfaceOp: { op: 'replace', start: first, end: last },
+      sourceEventSeqs: [startSeq, summarySeq, ...surfaceSeqs],
+    }),
+    at({ type: 'compact/end', data: { turn: 2 } }),
+    at({ type: 'turn/end', data: { turn: 2, reason: { kind: 'completed' } } }),
+  )
+  return `${lines.join('\n')}\n`
+}
+
 describe('web e2e: seeded history renders through cold resume', () => {
   let scaffold: WebScaffold
   let browser: Browser
@@ -46,7 +117,7 @@ describe('web e2e: seeded history renders through cold resume', () => {
     if (MODE !== 'record') {
       const raw = await readFile(SEED, 'utf8')
       expect(fixtureUserPrompts(raw), 'seed fixture must carry exactly the drive prompt').toEqual([PROMPT])
-      await seedSession(scaffold, raw, SEED_ID)
+      await seedSession(scaffold, withCompaction(raw), SEED_ID)
     }
     browser = await chromium.launch()
     page = await browser.newPage({ viewport: { width: 1680, height: 1000 } })
@@ -112,11 +183,15 @@ describe('web e2e: seeded history renders through cold resume', () => {
     await sessionRow.click()
     // Settled barrier for history: the recorded final assistant text renders.
     await expect.poll(() => page.getByText('DONE', { exact: true }).count(), { timeout: 15_000 }).toBe(1)
+    await expect.poll(() => page.getByText('上下文已压缩', { exact: true }).count(), { timeout: 10_000 }).toBe(1)
     // Tool cards render from logged tool/call + tool/result alone (views are
     // host-recomputed per page; the generic card is the documented default).
     const toolRows = page.locator('[data-variant], [data-sample]')
     await expect.poll(() => toolRows.count(), { timeout: 10_000 }).toBeGreaterThanOrEqual(2)
     expect(await page.getByText('a.txt', { exact: false }).count()).toBeGreaterThan(0)
+    // The bug this fixes: the compaction shadowed the whole recorded surface on
+    // the model side, and the prompt and full tool output are still on screen.
+    expect(await page.getByText(PROMPT, { exact: true }).count()).toBe(1)
   }, 60_000)
 
   it.skipIf(MODE === 'record')('matches the historical conversation aria golden', async () => {
@@ -147,6 +222,22 @@ describe('web e2e: seeded history renders through cold resume', () => {
     await expect.poll(() => page.getByText('a.txt', { exact: false }).count(), { timeout: 5_000 }).toBeGreaterThan(0)
   })
 
+  it.skipIf(MODE === 'record')('expands the cold-resumed compact summary', async () => {
+    onTestFailed(() => saveFailureShot(page, 'web-e2e-seeded-compaction'))
+    const marker = page.getByRole('button', { name: /上下文已压缩/ })
+    await marker.waitFor({ timeout: 10_000 })
+    expect(await marker.getAttribute('aria-expanded')).toBe('false')
+    await marker.click()
+    await expect.poll(() => marker.getAttribute('aria-expanded'), { timeout: 5_000 }).toBe('true')
+    await expect.poll(() => page.getByRole('heading', { name: 'Cold resume compact summary' }).count(), {
+      timeout: 5_000,
+    }).toBe(1)
+    expect(await page.getByText('The exact summary remains available.', { exact: false }).count()).toBeGreaterThan(0)
+    // Collapse again so the aria golden captured after this case is unaffected.
+    await marker.click()
+    await expect.poll(() => marker.getAttribute('aria-expanded'), { timeout: 5_000 }).toBe('false')
+  })
+
   it.skipIf(MODE === 'record')('issued zero model calls and stayed clean', async () => {
     // No replay fixture was installed and the llm seam is open — any stray
     // stream would have failed the turn loudly. Cleanliness pins the wire.

apps/web/tests/snapshots/seeded-history/ui.expected.md

@@ -36,7 +36,11 @@
   - img
 - button "在新对话中分支":
   - img
-- text: {{clock}} cache hit 98% · 15,962 tokens · 1 turns · 2 steps
+- text: {{clock}}
+- button "上下文已压缩 点击查看压缩摘要":
+  - img
+  - text: 上下文已压缩 点击查看压缩摘要
+- text: cache hit 98% · 15,962 tokens · 1 turns · 2 steps
 - textbox "Message the agent"
 - button "Add attachment":
   - img

packages/client/runtime/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/runtime/README.md
-README.md: 25eb60e2c95059ae918669c9f5169b6b8e9c6816
-README.zh.md: e3085f91750503aeaffda41d86c40c62943b4ba9
+README.md: 7bf8050ea988945bead491d02528906863b129a6
+README.zh.md: ff3c91dee956b2c65f0029c97c73d73f5a627b05

packages/client/runtime/README.md

@@ -16,9 +16,15 @@ SlotsService gives the renderer separate bare observables for `useSessions` and
 
 `WorkspacesService.connectWorkspace(workspaceId)` resolves the session a New Session flow lands in: it reuses the workspace's existing blank session from the list mirror (`blank && cwd == workspace.path`) or calls `session.create({workspaceId})`, returning the session id for the caller to open. `SessionSummary.blank` mirrors the host's derived empty-log bit and only ever lowers on the client: seeded by `session.list` / the `host/session-added` frame, flipped false by the first ACCEPTED local `prompt()` (on the RPC success response — acceptance proves the user message is in the host log; a rejected first prompt keeps the session blank and reusable) and by any `running: true` status frame, re-aligned by every list re-pull. List surfaces hide blank rows; the store carries every row. `SessionsService.create` accepts an optional caller-preallocated SessionId and throws `SessionCreateError` (carrying `requestedSessionId`) on failure.
 
+## The human transcript
+
+`ConversationSnapshot.nodes` is the human transcript, not the model surface. `TranscriptAdapter` projects the raw window in log order — every append-origin surface event (`isAppendSurfaceEvent`) at its own log position, plus one `CompactionSummaryNode` marker per landed compaction checkpoint — and never consults surface order. A landed compaction therefore keeps the conversation it shadowed on the model side: the marker reports where the model stopped seeing that history instead of erasing it. Model-only replacement copies stay out: a pruned `tool/result` and a regenerated `assistant/message` rewrite one node for the model and mark no boundary. A checkpoint is a `user/message` carrying the compaction seam's plugin source that **replaced** a surface range; an appending plugin-sourced `user/message` is injected context, not a compaction. That source literal is restated locally because `dsh-compact` is unreachable from this program in both directions (the client purity gate rejects a value import; a type-only import collides the host `Context.sessions` merge) — `tests/compact-checkpoint-pin.spec.ts` is the drift trap.
+
+Because the projection is log-ordered, the node array is seq-monotonic by construction: log-only `command/run` / `command/done` nodes splice in by seq, `Session` merges interrupted frozen nodes by their fractional seqs, and a window whose checkpoint cites a shadowed range outside it renders the marker with nothing logged. The marker's summary text comes from the checkpoint's `compact/summary` provenance; a window cut that left the provenance outside makes the row non-expandable rather than empty, and a later page that supplies it resolves the text. Performance contract: one append materializes one node, an event that changes no node keeps the previous array reference (a chunk storm costs nothing), and unchanged nodes keep their object identity.
+
 ## Code Mode sub-dispatch index
 
-`ConversationSnapshot.codeDispatches` groups a `run_code` call's sub-dispatches under their parent callId, in start order, using the native call-block shapes: a `tool/code-dispatch-start` event lands the `RunningToolCall` form (rows derive the running ring from the shape) and its `tool/code-dispatch` settlement replaces it in place with the `ToolResultNode` form, `callTime` carrying the paired start's time. A settle whose start fell outside the replay window appends directly with `callTime: null` (duration unknown — never a fabricated zero). Live mux frames and history replay build the identical index; sub-calls never join the surface `nodes` flow; per-parent array and map references are memo-stable across unrelated snapshot swaps.
+`ConversationSnapshot.codeDispatches` groups a `run_code` call's sub-dispatches under their parent callId, in start order, using the native call-block shapes: a `tool/code-dispatch-start` event lands the `RunningToolCall` form (rows derive the running ring from the shape) and its `tool/code-dispatch` settlement replaces it in place with the `ToolResultNode` form, `callTime` carrying the paired start's time. A settle whose start fell outside the replay window appends directly with `callTime: null` (duration unknown — never a fabricated zero). Live mux frames and history replay build the identical index; sub-calls never join the transcript `nodes` flow; per-parent array and map references are memo-stable across unrelated snapshot swaps.
 
 ## Session title projection
 

packages/client/runtime/README.zh.md

@@ -16,9 +16,15 @@ SlotsService 分别为 renderer 提供 `useSessions` 与 `useWorkspaces` 的裸
 
 `WorkspacesService.connectWorkspace(workspaceId)` 解析 New Session 流程最终落入的会话：先在列表镜像中复用该 workspace 的既有空会话（`blank && cwd == workspace.path`），未命中则调用 `session.create({workspaceId})`，返回会话 id 由调用方 open。`SessionSummary.blank` 镜像主机派生的空日志位，在客户端只降不升：由 `session.list`／`host/session-added` 帧播种，本地首次**受理成功**的 `prompt()`（RPC 成功响应时——受理即证明用户消息已入主机日志；首讯被拒则会话保持 blank、保持可复用）与任何 `running: true` 状态帧翻为 false，每次列表重拉重新对齐。列表表面隐藏 blank 行；store 保留全部行。`SessionsService.create` 接受可选的、由调用方预先分配的 SessionId，失败时抛出 `SessionCreateError`（携带 `requestedSessionId`）。
 
+## 人类对话记录
+
+`ConversationSnapshot.nodes` 是人类对话记录，不是模型 surface。`TranscriptAdapter` 按日志顺序投影原始窗口——每个 append 来源的 surface 事件（`isAppendSurfaceEvent`）落在它自己的日志位置上，外加每次落地的压缩检查点贡献一个 `CompactionSummaryNode` 标记——且从不查询 surface 顺序。于是一次落地的压缩会保留它在模型侧遮蔽掉的对话：标记报告模型从哪里开始看不见那段历史，而不是把它抹掉。仅模型可见的 replacement 副本不进入记录：被裁剪的 `tool/result` 和重新生成的 `assistant/message` 只为模型重写一个节点，不标记任何边界。检查点是携带压缩缝隙插件来源、且**替换**了一段 surface 范围的 `user/message`；一条 append 的插件来源 `user/message` 是注入上下文，不是压缩。该来源字面量在本地重述，因为 `dsh-compact` 在两个方向上都无法从本程序到达（客户端纯度门禁拒绝值导入；仅类型导入会与 host 的 `Context.sessions` 合并冲突）——`tests/compact-checkpoint-pin.spec.ts` 是漂移陷阱。
+
+由于投影按日志顺序，节点数组天然按 seq 单调：仅日志的 `command/run` / `command/done` 节点按 seq 插入，`Session` 按分数 seq 归并被打断的冻结节点，而检查点所引范围落在窗口之外的窗口会渲染出标记且不打印任何日志。标记的摘要文本来自检查点的 `compact/summary` 溯源；窗口切分把溯源留在窗口外时该行不可展开而非空白，后续补上溯源的分页会解析出文本。性能契约：一次追加物化一个节点，不改变任何节点的事件保持上一次的数组引用（分片风暴零成本），未变化的节点保持其对象标识。
+
 ## Code Mode 子调用索引
 
-`ConversationSnapshot.codeDispatches` 按父调用的 callId 和启动顺序，用原生调用块形状组织一个 `run_code` 调用的子调用：`tool/code-dispatch-start` 事件落成 `RunningToolCall` 形状（行组件从该形状推导运行中的转圈状态），其 `tool/code-dispatch` 完结事件原位替换为 `ToolResultNode` 形状，`callTime` 携带成对 start 事件的时间。start 落在回放窗口之外的完结事件则直接追加，`callTime: null`（耗时未知——绝不伪造零耗时）。live mux 帧与历史回放构建相同的索引；子调用永不进入 surface `nodes` 流；无关快照交换不会改变每个父调用对应的数组引用和映射引用，两者均保持 memo 稳定。
+`ConversationSnapshot.codeDispatches` 按父调用的 callId 和启动顺序，用原生调用块形状组织一个 `run_code` 调用的子调用：`tool/code-dispatch-start` 事件落成 `RunningToolCall` 形状（行组件从该形状推导运行中的转圈状态），其 `tool/code-dispatch` 完结事件原位替换为 `ToolResultNode` 形状，`callTime` 携带成对 start 事件的时间。start 落在回放窗口之外的完结事件则直接追加，`callTime: null`（耗时未知——绝不伪造零耗时）。live mux 帧与历史回放构建相同的索引；子调用永不进入对话记录 `nodes` 流；无关快照交换不会改变每个父调用对应的数组引用和映射引用，两者均保持 memo 稳定。
 
 ## Session 标题投影
 

packages/client/runtime/package.json

@@ -48,6 +48,7 @@
     "cordis": "^4.0.0-rc.7"
   },
   "devDependencies": {
+    "@deepseek-ai/dsh-compact": "workspace:^",
     "@deepseek-ai/dsh-invariants": "workspace:^",
     "@types/react": "~18.3.1",
     "cordis": "^4.0.0-rc.7"

packages/client/runtime/src/client/index.ts

@@ -38,8 +38,8 @@ export type {
   EngineStoreHandle, EngineStoreInstance, ObservableSnapshot, SnapshotStore,
 } from './contract/store.ts'
 export type {
-  AssistantBlock, AssistantMessageNode, CodeSubCall, CommandNode, ComposerPhase, ContextMessageNode, ConversationNode,
-  ConversationSnapshot, QueuedMessage, RunningToolCall,
+  AssistantBlock, AssistantMessageNode, CodeSubCall, CommandNode, CompactionSummaryNode, ComposerPhase,
+  ContextMessageNode, ConversationNode, ConversationSnapshot, QueuedMessage, RunningToolCall,
   SteeringMessageNode, TodoItem, ToolResultNode, UnknownSurfaceNode, UserMessageNode,
 } from './sessions/conversation.ts'
 export { PendingWait } from './sessions/pending.ts'

packages/client/runtime/src/client/sessions/conversation.ts

@@ -111,6 +111,24 @@ export interface ToolResultNode {
   resultView: ToolResultView | null
 }
 
+/**
+ * One landed compaction, marked at the checkpoint's own log position. The
+ * conversation it shadowed on the model surface stays in the transcript above
+ * it: the marker reports where the model stopped seeing that history, it does
+ * not replace it. The framed checkpoint payload is an instruction envelope
+ * written for the model and never renders.
+ */
+export interface CompactionSummaryNode {
+  kind: 'compaction'
+  /** Seq of the replacement `user/message` that landed the checkpoint. */
+  seq: number
+  /** Unix epoch ms of the checkpoint event. */
+  time: number
+  /** Summary text from the checkpoint's `compact/summary` provenance; null when
+   *  the window cut left that provenance outside (the marker is then not expandable). */
+  summary: string | null
+}
+
 /** Fallback for surface events this UI version does not know. */
 export interface UnknownSurfaceNode {
   kind: 'unknown'
@@ -124,7 +142,7 @@ export interface UnknownSurfaceNode {
 /**
  * One slash-command lifecycle folded from the log-only `command/run` /
  * `command/done` pair (paired by commandId, mirroring tool call↔result).
- * Log-only events never enter the surface fold, so the FoldAdapter indexes
+ * Log-only events are not surface events, so the TranscriptAdapter indexes
  * them separately and merges the nodes into the flow by seq. A window cut
  * between the pair soft-falls like tool pairs: a done with no in-window run
  * still builds a node (name/args null), and a run with no done renders as
@@ -154,6 +172,7 @@ export type ConversationNode =
   | ContextMessageNode
   | ToolResultNode
   | CommandNode
+  | CompactionSummaryNode
   | UnknownSurfaceNode
 
 /**
@@ -163,7 +182,7 @@ export type ConversationNode =
  * {@link RunningToolCall} (rows derive the running state from the shape,
  * exactly as for native calls) and its `tool/code-dispatch` settlement
  * replaces it in place with the {@link ToolResultNode} form. Never part of
- * the surface `nodes` flow — sub-calls live under their parent via
+ * the transcript `nodes` flow — sub-calls live under their parent via
  * {@link ConversationSnapshot.codeDispatches}. `callId` is the deterministic
  * sub-call id (`<parent>:code:<n>`); the call side carries the sub-tool name
  * and its JSON-stringified logged arguments; `content`/`isError` are the
@@ -232,10 +251,8 @@ export interface PromptError {
 /** The immutable snapshot contract Session hands to uSES (see the web client architecture RFC). */
 export interface ConversationSnapshot {
   sessionId: SessionId
-  /** Surface fold product (finalized conversation nodes in surface order). */
+  /** Human transcript (finalized conversation nodes in log order). */
   nodes: readonly ConversationNode[]
-  /** Fold degradation flag (cross-window replace defense): when true, nodes come from the lenient linear scan. */
-  foldDegraded: boolean
   partial: PartialAssistant | null
   runningCalls: readonly RunningToolCall[]
   /**

packages/client/runtime/src/client/sessions/fold-adapter.ts

@@ -1,275 +0,0 @@
-// FoldAdapter: core SurfaceManager wiring + node materialization cache.
-// Padding sentinels solve the paged-window seq offset (core fold asserts seq === index);
-// a cross-window replace throw degrades to a lenient linear scan (foldDegraded —
-// the degradation lives in one branch function in this file, zero scattered removal points).
-
-import type { SessionEvent } from '@deepseek-ai/dsh-session/types'
-// Subpath export (package.json exports "./surface", alias added for this): all value imports
-// go through it — the package root points at lib/index.js (needs a build) which the vite
-// browser bundle cannot resolve; surface.ts has no Node dependencies.
-import { SurfaceManager, isSurfaceEligibleType } from '@deepseek-ai/dsh-session/surface'
-import type { CommandId } from '@deepseek-ai/dsh-commands/brand'
-import type { ToolCallView, ToolEventView, ToolResultView } from '@deepseek-ai/dsh-client-connection/client'
-import type { CommandNode, ConversationNode } from './conversation.ts'
-import { toAssistantBlocks } from './conversation.ts'
-
-/** In-window tool/call index entry (result-card backfill + runningCalls material). */
-export interface CallIndexEntry {
-  name: string
-  argsRaw: string
-  turn: number
-  step: number
-  /** Unix epoch ms of the tool/call event. */
-  time: number
-  /** Wire view riding the tool/call (envelope-level; never inside the event). */
-  callView: ToolCallView | null
-}
-
-/** Non-surface sentinel used to preserve paged-window sequence offsets.
- * `noop/padding` is deliberately not a real event type, so it cannot acquire
- * surface behavior; this cast is the only synthetic event entry point.
- */
-function paddingEvent(seq: number): SessionEvent {
-  return { type: 'noop/padding', seq, time: 0, data: {} } as unknown as SessionEvent
-}
-
-/** One event -> UI node (pure function; the six-variant ConversationNode union). */
-function materializeNode(
-  event: SessionEvent,
-  callIndex: ReadonlyMap<string, CallIndexEntry>,
-  resultView: ToolResultView | null,
-): ConversationNode {
-  switch (event.type) {
-    case 'user/message':
-      // Injected context (plugin/goal source) folds to a context node, not a
-      // user message; only a direct human prompt is a user node.
-      if (event.data.source.kind !== 'user') {
-        return {
-          kind: 'context', seq: event.seq, time: event.time,
-          content: event.data.content, source: event.data.source,
-        }
-      }
-      return {
-        kind: 'user', seq: event.seq, time: event.time,
-        content: event.data.content, source: event.data.source,
-      }
-    case 'assistant/message':
-      return {
-        kind: 'assistant', seq: event.seq, time: event.time,
-        turn: event.data.turn, step: event.data.step,
-        blocks: toAssistantBlocks(event.data.message.content), usage: event.data.usage,
-      }
-    case 'steering/message':
-      return {
-        kind: 'steering', seq: event.seq, time: event.time, turn: event.data.turn,
-        content: event.data.message.content, source: event.data.message.source,
-      }
-    case 'tool/result': {
-      const result = event.data.message.content[0]
-      const callId = String(event.data.message.source.callId)
-      const call = callIndex.get(callId)
-      return {
-        kind: 'tool-result', seq: event.seq, time: event.time,
-        callId,
-        call: call ? { name: call.name, argsRaw: call.argsRaw } : null,
-        callTime: call?.time ?? null,
-        content: result.content, isError: result.isError === true,
-        ...(event.data.error !== undefined ? { error: event.data.error } : {}),
-        meta: event.data.meta,
-        callView: call?.callView ?? null,
-        resultView,
-      }
-    }
-    /* v8 ignore next 2 -- defensive arm: fold output only carries the four
-    surface-eligible types, and each has a case above; reachable only if core
-    adds an eligible type. */
-    default:
-      return {
-        kind: 'unknown', seq: event.seq, time: event.time,
-        type: event.type, data: (event as { data?: unknown }).data,
-      }
-  }
-}
-
-/** Window fold over the core SurfaceManager (sentinel padding for the seq offset; degrades to a linear scan on cross-window replace). */
-export class FoldAdapter {
-  /** padded = [sentinel x baseSeq, ...window events]; SurfaceManager borrows this reference for lazy incremental folding. */
-  private padded: SessionEvent[] = []
-  private baseSeq = 0
-  private surface = new SurfaceManager(this.padded)
-  private nodeCache = new Map<number, ConversationNode>()
-  private degraded = false
-  private callIdx = new Map<string, CallIndexEntry>()
-  /** Wire result views keyed by the tool/result event's seq (views ride the envelope, not the event). */
-  private resultViews = new Map<number, ToolResultView>()
-  /**
-   * Command lifecycle nodes by commandId (insertion = run order). The
-   * `command/run`/`command/done` pair is log-only, so the surface fold never
-   * emits it; this index folds the pair (done settles its run's node in
-   * place) and nodes() merges the products into the flow by seq. Window cuts
-   * soft-fall like tool pairs: a done with no in-window run still builds a
-   * node.
-   */
-  private commandIdx = new Map<string, CommandNode>()
-  /** Window revision (bumped on reset/append) keying the nodes() result cache: an unchanged
-   *  window returns the previous ARRAY reference, not just cached elements — the snapshot's
-   *  reference-stability contract (§A.9.4) starts here. */
-  private rev = 0
-  private nodesResult: { rev: number; value: { nodes: ConversationNode[]; degraded: boolean } } | null = null
-
-  /** In-window tool/call index (Session uses it for runningCalls and result-card backfill). */
-  get callIndex(): ReadonlyMap<string, CallIndexEntry> {
-    return this.callIdx
-  }
-
-  /**
-   * Window rebuild (after open/resync/page prepend): new padded array, new
-   * SurfaceManager, cleared cache, rebuilt callIndex.
-   * @param events - the new window contents (seq-ascending).
-   * @param baseSeq - seq of the window head (sentinels pad below it).
-   * @param views - per-event wire views aligned with `events` by index (undefined slots for view-less events).
-   */
-  reset(events: readonly SessionEvent[], baseSeq: number, views?: readonly (ToolEventView | undefined)[]): void {
-    this.rev++
-    this.baseSeq = baseSeq
-    this.padded = []
-    for (let i = 0; i < baseSeq; i++) this.padded.push(paddingEvent(i))
-    for (const event of events) this.padded.push(event)
-    this.surface = new SurfaceManager(this.padded)
-    this.nodeCache.clear()
-    this.degraded = false
-    this.callIdx = new Map()
-    this.resultViews.clear()
-    this.commandIdx = new Map()
-    for (let i = 0; i < events.length; i++) {
-      const event = events[i]
-      /* v8 ignore next -- dense-array guard: i stays within events.length, so the undefined arm needs a sparse array no caller builds. */
-      if (event !== undefined) {
-        this.indexCall(event, views?.[i])
-        this.indexCommand(event)
-      }
-    }
-  }
-
-  /**
-   * Tail append (live session/event): push into the same array (incremental
-   * lazy fold applies) + incremental callIndex upkeep.
-   * @param event - the live event (seq = window tail + 1).
-   * @param view - host-computed tool view paired with the event when it is a tool call/result; indexed for card rendering.
-   */
-  append(event: SessionEvent, view?: ToolEventView): void {
-    this.rev++
-    this.padded.push(event)
-    this.indexCall(event, view)
-    this.indexCommand(event)
-  }
-
-  /**
-   * Current node array + degradation flag. Same revision -> same array
-   * reference (memo boundary); node object references always come from the per-seq cache.
-   * @returns the fold projection for the current window revision.
-   */
-  nodes(): { nodes: ConversationNode[]; degraded: boolean } {
-    if (this.nodesResult !== null && this.nodesResult.rev === this.rev) return this.nodesResult.value
-    let seqs: readonly number[]
-    if (this.degraded) {
-      seqs = this.degradedSeqs()
-    } else {
-      try {
-        seqs = this.surface.nodes
-      } catch (error) {
-        console.error('[web-runtime] surface fold failed, degrading to linear scan:', error)
-        this.degraded = true
-        seqs = this.degradedSeqs()
-      }
-    }
-    const out: ConversationNode[] = []
-    for (const seq of seqs) {
-      const cached = this.nodeCache.get(seq)
-      if (cached !== undefined) {
-        out.push(cached)
-        continue
-      }
-      const event = this.padded[seq]
-      /* v8 ignore next -- sparse guard: both seq sources (surface fold and degradedSeqs) only emit indexes present in padded. */
-      if (event === undefined) continue
-      const node = materializeNode(event, this.callIdx, this.resultViews.get(seq) ?? null)
-      this.nodeCache.set(seq, node)
-      out.push(node)
-    }
-    // Command nodes fold outside the surface (log-only events); merge by seq.
-    // Both inputs are seq-ascending (surface order and run-index insertion
-    // order share the log order), so one linear merge keeps flow order.
-    let nodes = out
-    if (this.commandIdx.size > 0) {
-      nodes = []
-      const commands = [...this.commandIdx.values()]
-      let next = 0
-      for (const node of out) {
-        for (let cmd = commands[next]; cmd !== undefined && cmd.seq < node.seq; cmd = commands[++next]) {
-          nodes.push(cmd)
-        }
-        nodes.push(node)
-      }
-      for (let cmd = commands[next]; cmd !== undefined; cmd = commands[++next]) nodes.push(cmd)
-    }
-    const value = { nodes, degraded: this.degraded }
-    this.nodesResult = { rev: this.rev, value }
-    return value
-  }
-
-  /** Degradation branch: lenient linear scan ignoring surfaceOp/replace (all surface-eligible events in append order). */
-  private degradedSeqs(): number[] {
-    const seqs: number[] = []
-    for (let i = this.baseSeq; i < this.padded.length; i++) {
-      const event = this.padded[i]
-      if (event !== undefined && isSurfaceEligibleType(event.type)) seqs.push(event.seq)
-    }
-    return seqs
-  }
-
-  /** Fold one command lifecycle event into its node (run mints, done settles in place; done-only soft-falls). */
-  private indexCommand(event: SessionEvent): void {
-    // Log-only plugin events: the host-side dsh-commands declaration cannot
-    // enter the client program, so this wire consumer narrows structurally
-    // (the same posture as tool/code-dispatch in session.ts).
-    if ((event.type as string) === 'command/run') {
-      const data = event.data as unknown as { commandId: CommandId; name: string; args: string }
-      this.commandIdx.set(data.commandId, {
-        kind: 'command', seq: event.seq, time: event.time,
-        commandId: data.commandId, name: data.name, args: data.args, outcome: null,
-      })
-      return
-    }
-    if ((event.type as string) !== 'command/done') return
-    const data = event.data as unknown as { commandId: CommandId; kind: 'success' | 'error'; text?: string }
-    const run = this.commandIdx.get(data.commandId)
-    const outcome = { kind: data.kind, ...data.text === undefined ? {} : { text: data.text } }
-    if (run === undefined) {
-      // Cross-window cut: the run page fell out of the window — build the
-      // node from the done alone (same soft-fall as a call-less tool result).
-      this.commandIdx.set(data.commandId, {
-        kind: 'command', seq: event.seq, time: event.time,
-        commandId: data.commandId, name: null, args: null, outcome,
-      })
-      return
-    }
-    // Settle in place: a fresh node object (published references stay immutable).
-    this.commandIdx.set(data.commandId, { ...run, outcome })
-  }
-
-  private indexCall(event: SessionEvent, view?: ToolEventView): void {
-    if (event.type === 'tool/result') {
-      if (view?.for === 'result') this.resultViews.set(event.seq, view.view)
-      return
-    }
-    if (event.type !== 'tool/call') return
-    this.callIdx.set(String(event.data.callId), {
-      name: event.data.name, argsRaw: event.data.arguments, turn: event.data.turn, step: event.data.step,
-      time: event.time,
-      callView: view?.for === 'call' ? view.view : null,
-    })
-    // No backfill into already-materialized tool-result nodes for this callId
-    // (window order puts the call before its result; cannot happen on the normal path).
-  }
-}

packages/client/runtime/src/client/sessions/session.ts

@@ -17,7 +17,7 @@ import type {
 } from './conversation.ts'
 import type { PendingInteraction } from './pending.ts'
 import { PendingWait } from './pending.ts'
-import { FoldAdapter } from './fold-adapter.ts'
+import { TranscriptAdapter } from './transcript-adapter.ts'
 import { Notifier } from './notifier.ts'
 import { PartialAccumulator } from './partial.ts'
 import { ProjectionValueStore } from './projection-store.ts'
@@ -87,11 +87,13 @@ export class Session implements SessionFace {
    *  passes drop all writes once the generation moves on. */
   private openGeneration = 0
   private loadingOlder = false
-  private readonly foldAdapter = new FoldAdapter()
+  private readonly transcript = new TranscriptAdapter()
   private partial: PartialAccumulator | null = null
   private openCalls = new Map<string, RunningToolCall>()
   /** Interrupted-turn terminal nodes (frozen partial text / aborted tool cards), merged into the flow by seq.
-   *  Derived from window events (turn/end sweep) — rebuilt by rebuildDerivedFromWindow like partial/openCalls. */
+   *  Derived from window events (turn/end sweep) — rebuilt by rebuildDerivedFromWindow like partial/openCalls.
+   *  Owned here rather than by the adapter: these nodes come from the turn/end sweep this class already
+   *  runs over the window, and the transcript array is seq-monotonic, so a plain seq merge is correct. */
   private frozenNodes: ConversationNode[] = []
   private pending = new Map<string, PendingInteraction>()
   // Revision counters preserve array identity when derived content is unchanged, so
@@ -108,7 +110,7 @@ export class Session implements SessionFace {
   private queueRev = 0
   private queueCache: { rev: number; value: QueuedMessage[] } | null = null
   private frozenRev = 0
-  private nodesCache: { folded: readonly ConversationNode[]; frozenRev: number; value: readonly ConversationNode[] } | null = null
+  private nodesCache: { projected: readonly ConversationNode[]; frozenRev: number; value: readonly ConversationNode[] } | null = null
   /** `run_code` sub-dispatches by parent callId (window-derived, like openCalls). Appends
    *  copy-on-write the per-parent array so published snapshot references never mutate. */
   private codeDispatches = new Map<string, readonly CodeSubCall[]>()
@@ -306,7 +308,7 @@ export class Session implements SessionFace {
       /* v8 ignore next -- the ?? arm needs older[0] undefined, but the empty-page branch above already returned. */
       this.baseSeq = older[0]?.event.seq ?? this.baseSeq
       this.hasMore = result.value.hasMore
-      this.foldAdapter.reset(this.events, this.baseSeq, this.views) // prepend forces a rebuild (sentinel count changed)
+      this.transcript.reset(this.events, this.views) // prepend forces a rebuild (the window grew at the head)
       this.rebuildDerivedFromWindow()
     } catch (error) {
       console.error('[web-runtime] loadOlder failed:', error)
@@ -553,7 +555,7 @@ export class Session implements SessionFace {
     this.views = entries.map(e => e.view)
     this.baseSeq = this.events[0]?.seq ?? 0
     this.hasMore = hasMore
-    this.foldAdapter.reset(this.events, this.baseSeq, this.views)
+    this.transcript.reset(this.events, this.views)
     this.rebuildDerivedFromWindow()
     if (projections !== undefined) this.projections.seed(projections)
     const buffered = this.liveBuffer
@@ -568,14 +570,15 @@ export class Session implements SessionFace {
     if (tailSeq !== null && event.seq <= tailSeq) return // replay overlap, drop
     this.events.push(event)
     this.views.push(view)
-    this.foldAdapter.append(event, view)
+    this.transcript.append(event, view)
     this.applyEventSideEffects(event, view)
   }
 
   /** Land a live session/event (open/repair in flight -> buffer; overlapping seq -> drop;
    *  a seq gap -> buffer + tail-page repull instead of appending a hole (audit S3: a gap is an
-   *  expected reconnect-window artifact, repaired by refetch — never fed to the fold to trip
-   *  its continuity assertion into the degraded view). */
+   *  expected reconnect-window artifact, repaired by refetch). The window stays one contiguous
+   *  raw range, which is what lets the transcript render every event between its ends and lets a
+   *  compaction checkpoint find its own provenance. */
   private acceptLiveEvent(event: SessionEvent, view?: ToolEventView): void {
     if (this.openState === 'loading' || this.stitching) {
       this.liveBuffer.push({ event, view })
@@ -790,18 +793,19 @@ export class Session implements SessionFace {
   }
 
   private buildSnapshot(): ConversationSnapshot {
-    const { nodes: folded, degraded } = this.foldAdapter.nodes()
+    const projected = this.transcript.nodes()
     // Frozen interrupted nodes ride fractional seqs: a stable merge keeps them in flow order.
-    // The merged array is cached on (folded reference, frozenRev) so an unchanged flow keeps its
-    // reference across snapshot swaps (§A.9.4).
+    // The transcript is seq-monotonic (log order), so sorting the union by seq is exactly the
+    // flow order. The merged array is cached on (projected reference, frozenRev) so an unchanged
+    // flow keeps its reference across snapshot swaps (§A.9.4).
     let nodes: readonly ConversationNode[]
-    if (this.nodesCache !== null && this.nodesCache.folded === folded && this.nodesCache.frozenRev === this.frozenRev) {
+    if (this.nodesCache !== null && this.nodesCache.projected === projected && this.nodesCache.frozenRev === this.frozenRev) {
       nodes = this.nodesCache.value
     } else {
       nodes = this.frozenNodes.length === 0
-        ? folded
-        : [...folded, ...this.frozenNodes].sort((a, b) => a.seq - b.seq)
-      this.nodesCache = { folded, frozenRev: this.frozenRev, value: nodes }
+        ? projected
+        : [...projected, ...this.frozenNodes].sort((a, b) => a.seq - b.seq)
+      this.nodesCache = { projected, frozenRev: this.frozenRev, value: nodes }
     }
     if (this.callsCache === null || this.callsCache.rev !== this.callsRev) {
       this.callsCache = { rev: this.callsRev, value: [...this.openCalls.values()] }
@@ -819,7 +823,6 @@ export class Session implements SessionFace {
     return {
       sessionId: this.sessionId,
       nodes,
-      foldDegraded: degraded,
       partial,
       runningCalls: this.callsCache.value,
       pending: this.pendingCache.value,

packages/client/runtime/src/client/sessions/transcript-adapter.ts

@@ -0,0 +1,325 @@
+// TranscriptAdapter: the human transcript projected from the raw event window
+// in LOG order. The model-visible surface deliberately shadows replaced ranges,
+// so it is the wrong source for conversation a reader already saw; this adapter
+// keeps every append-origin event at its own log position and contributes one
+// marker node per landed compaction checkpoint. Node order is therefore
+// seq-monotonic by construction — no surface fold, no padding sentinels, no
+// seq === index assertion to satisfy, and no degradation branch.
+
+import type { SessionEvent } from '@deepseek-ai/dsh-session/types'
+// Subpath export (package.json exports "./surface", alias added for this): all value imports
+// go through it — the package root points at lib/index.js (needs a build) which the vite
+// browser bundle cannot resolve; surface.ts has no Node dependencies.
+import { isAppendSurfaceEvent, isReplacementSurfaceEvent } from '@deepseek-ai/dsh-session/surface'
+import type { CommandId } from '@deepseek-ai/dsh-commands/brand'
+import type { ToolCallView, ToolEventView, ToolResultView } from '@deepseek-ai/dsh-client-connection/client'
+import type { CommandNode, CompactionSummaryNode, ConversationNode } from './conversation.ts'
+import { toAssistantBlocks } from './conversation.ts'
+
+/**
+ * The compaction seam's checkpoint plugin, restated locally.
+ *
+ * `dsh-compact` cannot be reached from this program in any form. A VALUE import
+ * fails the client purity gate (`packages/client/tsdown.client.ts`) and would
+ * pull the cordis `Service` base into the browser bundle; a TYPE-ONLY import of
+ * its `COMPACT_CHECKPOINT_SOURCE` fails typecheck, because `dsh-compact`'s root
+ * reaches `dsh-session`'s root, whose `Context` merge declares the HOST
+ * `sessions: SessionStore` against this program's `sessions: ISessions`
+ * (`TS2717` — the one-program-per-side rule in docs/development.md). The
+ * literal is pinned to the canonical const by
+ * `tests/compact-checkpoint-pin.spec.ts`, which runs in the client TEST program
+ * where that collision does not apply.
+ */
+const COMPACT_PLUGIN = 'compact'
+
+/** In-window tool/call index entry (result-card backfill + runningCalls material). */
+export interface CallIndexEntry {
+  name: string
+  argsRaw: string
+  turn: number
+  step: number
+  /** Unix epoch ms of the tool/call event. */
+  time: number
+  /** Wire view riding the tool/call (envelope-level; never inside the event). */
+  callView: ToolCallView | null
+}
+
+/** One event -> UI node (pure function; the eight-variant ConversationNode union). */
+function materializeNode(
+  event: SessionEvent,
+  callIndex: ReadonlyMap<string, CallIndexEntry>,
+  resultView: ToolResultView | null,
+): ConversationNode {
+  switch (event.type) {
+    case 'user/message':
+      // Injected context (plugin/goal source) folds to a context node, not a
+      // user message; only a direct human prompt is a user node. A compaction
+      // checkpoint never reaches here (isCompactCheckpoint routes it away).
+      if (event.data.source.kind !== 'user') {
+        return {
+          kind: 'context', seq: event.seq, time: event.time,
+          content: event.data.content, source: event.data.source,
+        }
+      }
+      return {
+        kind: 'user', seq: event.seq, time: event.time,
+        content: event.data.content, source: event.data.source,
+      }
+    case 'assistant/message':
+      return {
+        kind: 'assistant', seq: event.seq, time: event.time,
+        turn: event.data.turn, step: event.data.step,
+        blocks: toAssistantBlocks(event.data.message.content), usage: event.data.usage,
+      }
+    case 'steering/message':
+      return {
+        kind: 'steering', seq: event.seq, time: event.time, turn: event.data.turn,
+        content: event.data.message.content, source: event.data.message.source,
+      }
+    case 'tool/result': {
+      const result = event.data.message.content[0]
+      const callId = String(event.data.message.source.callId)
+      const call = callIndex.get(callId)
+      return {
+        kind: 'tool-result', seq: event.seq, time: event.time,
+        callId,
+        call: call ? { name: call.name, argsRaw: call.argsRaw } : null,
+        callTime: call?.time ?? null,
+        content: result.content, isError: result.isError === true,
+        ...(event.data.error !== undefined ? { error: event.data.error } : {}),
+        meta: event.data.meta,
+        callView: call?.callView ?? null,
+        resultView,
+      }
+    }
+    /* v8 ignore next 2 -- defensive arm: only the four surface-eligible types
+    can be append-origin, and each has a case above; reachable only if core
+    adds an eligible type. */
+    default:
+      return {
+        kind: 'unknown', seq: event.seq, time: event.time,
+        type: event.type, data: (event as { data?: unknown }).data,
+      }
+  }
+}
+
+/**
+ * Whether an event is a landed compaction checkpoint — all three conditions,
+ * matching the terminal's `isCompactCheckpoint`: a `user/message`, carrying the
+ * compaction seam's checkpoint plugin source, that REPLACED a surface range. A
+ * plugin-sourced `user/message` that appends is injected context (a
+ * session-reference card), not a compaction; a replacement `tool/result` is an
+ * in-place prune and a replacement `assistant/message` a generic rewrite, and
+ * both mark no boundary in the conversation.
+ * @param event - the raw window event.
+ * @returns true when the event compacted a surface range.
+ */
+function isCompactCheckpoint(event: SessionEvent): boolean {
+  if (event.type !== 'user/message') return false
+  const source = event.data.source
+  return source.kind === 'plugin' && source.plugin === COMPACT_PLUGIN
+    && isReplacementSurfaceEvent(event)
+}
+
+/** Whether an event contributes a node to the human transcript. */
+function isTranscriptEvent(event: SessionEvent): boolean {
+  return isAppendSurfaceEvent(event) || isCompactCheckpoint(event)
+}
+
+/** Concatenated text of a `compact/summary` payload, or null when it carries no usable text. */
+function compactSummaryText(event: SessionEvent): string | null {
+  const summary = (event.data as unknown as { summary?: unknown }).summary
+  if (!Array.isArray(summary) || summary.length === 0) return null
+  let text = ''
+  for (const block of summary as readonly unknown[]) {
+    const candidate = block as { type?: unknown; text?: unknown }
+    if (candidate.type !== 'text' || typeof candidate.text !== 'string') return null
+    text += candidate.text
+  }
+  return text.trim() === '' ? null : text
+}
+
+/**
+ * One landed checkpoint -> the human-facing compaction marker. The summary text
+ * comes from the checkpoint's own provenance (`sourceEventSeqs` names the
+ * `compact/summary` event), never from the framed checkpoint payload, which is
+ * an instruction envelope written for the model. A window cut that left the
+ * provenance outside soft-falls to `summary: null` (a non-expandable marker),
+ * the same posture as a call-less tool result.
+ */
+function materializeCompaction(
+  checkpoint: SessionEvent,
+  eventIndex: ReadonlyMap<number, SessionEvent>,
+): CompactionSummaryNode {
+  const sources = (checkpoint as SessionEvent & { sourceEventSeqs?: number[] }).sourceEventSeqs
+  let summary: string | null = null
+  for (const seq of sources ?? []) {
+    const candidate = eventIndex.get(seq)
+    if (candidate === undefined || (candidate.type as string) !== 'compact/summary') continue
+    summary = compactSummaryText(candidate)
+    break
+  }
+  return { kind: 'compaction', seq: checkpoint.seq, time: checkpoint.time, summary }
+}
+
+/** Log-ordered human transcript over a paged raw event window (never consults surface order). */
+export class TranscriptAdapter {
+  /** Window events by seq: provenance lookup for a checkpoint's summary. */
+  private eventIndex = new Map<number, SessionEvent>()
+  /** Transcript nodes in log order; copy-on-write so a published array never mutates. */
+  private projected: ConversationNode[] = []
+  private callIdx = new Map<string, CallIndexEntry>()
+  /** Wire result views keyed by the tool/result event's seq (views ride the envelope, not the event). */
+  private resultViews = new Map<number, ToolResultView>()
+  /**
+   * Command lifecycle nodes by commandId (insertion = run order). The
+   * `command/run`/`command/done` pair is log-only, so it is not a surface
+   * event and never joins the transcript projection; this index folds the pair
+   * (done settles its run's node in place) and nodes() merges the products in
+   * by seq. Window cuts soft-fall like tool pairs: a done with no in-window
+   * run still builds a node.
+   */
+  private commandIdx = new Map<string, CommandNode>()
+  /** Projection revision, bumped only when a transcript node or a command node actually
+   *  changed, keying the nodes() result cache: an unchanged projection returns the previous
+   *  ARRAY reference, not just cached elements — the snapshot's reference-stability contract
+   *  (§A.9.4) starts here, and a chunk storm bumps nothing at all. */
+  private rev = 0
+  private nodesResult: { rev: number; value: readonly ConversationNode[] } | null = null
+
+  /** In-window tool/call index (Session uses it for runningCalls and result-card backfill). */
+  get callIndex(): ReadonlyMap<string, CallIndexEntry> {
+    return this.callIdx
+  }
+
+  /**
+   * Window rebuild (after open/resync/page prepend): re-index the raw window
+   * and re-project the transcript.
+   * @param events - the new window contents (seq-ascending).
+   * @param views - per-event wire views aligned with `events` by index (undefined slots for view-less events).
+   */
+  reset(events: readonly SessionEvent[], views?: readonly (ToolEventView | undefined)[]): void {
+    this.rev++
+    this.eventIndex = new Map()
+    this.callIdx = new Map()
+    this.resultViews.clear()
+    this.commandIdx = new Map()
+    for (let i = 0; i < events.length; i++) {
+      const event = events[i]
+      /* v8 ignore next -- dense-array guard: i stays within events.length, so the undefined arm needs a sparse array no caller builds. */
+      if (event === undefined) continue
+      this.eventIndex.set(event.seq, event)
+      this.indexCall(event, views?.[i])
+      this.indexCommand(event)
+    }
+    // Indexes first, then project: a tool/result materializes against the
+    // complete call index, and a checkpoint against the complete event index.
+    const projected: ConversationNode[] = []
+    for (const event of events) {
+      if (isTranscriptEvent(event)) projected.push(this.materialize(event))
+    }
+    this.projected = projected
+  }
+
+  /**
+   * Tail append (live session/event): index the event and, when it belongs to
+   * the transcript, extend the projection by one node — O(1) per append. An
+   * event that changes no node (a chunk storm) bumps no revision, so nodes()
+   * keeps returning the same array reference.
+   * @param event - the live event (seq = window tail + 1).
+   * @param view - host-computed tool view paired with the event when it is a tool call/result; indexed for card rendering.
+   */
+  append(event: SessionEvent, view?: ToolEventView): void {
+    this.eventIndex.set(event.seq, event)
+    this.indexCall(event, view)
+    if (this.indexCommand(event)) this.rev++
+    if (!isTranscriptEvent(event)) return
+    this.projected = [...this.projected, this.materialize(event)]
+    this.rev++
+  }
+
+  /**
+   * The current transcript node array. Same revision -> same array reference
+   * (memo boundary); node objects are materialized once, so an unchanged node
+   * keeps its identity across appends.
+   * @returns transcript nodes in log order, command nodes merged in by seq.
+   */
+  nodes(): readonly ConversationNode[] {
+    if (this.nodesResult !== null && this.nodesResult.rev === this.rev) return this.nodesResult.value
+    // Command nodes fold outside the transcript (log-only events); merge by
+    // seq. Both inputs are seq-ascending (log order and run-index insertion
+    // order are the same order), so one linear merge keeps flow order.
+    let nodes = this.projected
+    if (this.commandIdx.size > 0) {
+      nodes = []
+      const commands = [...this.commandIdx.values()]
+      let next = 0
+      for (const node of this.projected) {
+        for (let cmd = commands[next]; cmd !== undefined && cmd.seq < node.seq; cmd = commands[++next]) {
+          nodes.push(cmd)
+        }
+        nodes.push(node)
+      }
+      for (let cmd = commands[next]; cmd !== undefined; cmd = commands[++next]) nodes.push(cmd)
+    }
+    this.nodesResult = { rev: this.rev, value: nodes }
+    return nodes
+  }
+
+  /** Materialize one transcript event against the complete current indexes. */
+  private materialize(event: SessionEvent): ConversationNode {
+    return isCompactCheckpoint(event)
+      ? materializeCompaction(event, this.eventIndex)
+      : materializeNode(event, this.callIdx, this.resultViews.get(event.seq) ?? null)
+  }
+
+  /**
+   * Fold one command lifecycle event into its node (run mints, done settles in
+   * place; done-only soft-falls).
+   * @returns whether the command index changed, so callers can bump the revision.
+   */
+  private indexCommand(event: SessionEvent): boolean {
+    // Log-only plugin events: the host-side dsh-commands declaration cannot
+    // enter the client program, so this wire consumer narrows structurally
+    // (the same posture as tool/code-dispatch in session.ts).
+    if ((event.type as string) === 'command/run') {
+      const data = event.data as unknown as { commandId: CommandId; name: string; args: string }
+      this.commandIdx.set(data.commandId, {
+        kind: 'command', seq: event.seq, time: event.time,
+        commandId: data.commandId, name: data.name, args: data.args, outcome: null,
+      })
+      return true
+    }
+    if ((event.type as string) !== 'command/done') return false
+    const data = event.data as unknown as { commandId: CommandId; kind: 'success' | 'error'; text?: string }
+    const run = this.commandIdx.get(data.commandId)
+    const outcome = { kind: data.kind, ...data.text === undefined ? {} : { text: data.text } }
+    if (run === undefined) {
+      // Cross-window cut: the run page fell out of the window — build the
+      // node from the done alone (same soft-fall as a call-less tool result).
+      this.commandIdx.set(data.commandId, {
+        kind: 'command', seq: event.seq, time: event.time,
+        commandId: data.commandId, name: null, args: null, outcome,
+      })
+      return true
+    }
+    // Settle in place: a fresh node object (published references stay immutable).
+    this.commandIdx.set(data.commandId, { ...run, outcome })
+    return true
+  }
+
+  private indexCall(event: SessionEvent, view?: ToolEventView): void {
+    if (event.type === 'tool/result') {
+      if (view?.for === 'result') this.resultViews.set(event.seq, view.view)
+      return
+    }
+    if (event.type !== 'tool/call') return
+    this.callIdx.set(String(event.data.callId), {
+      name: event.data.name, argsRaw: event.data.arguments, turn: event.data.turn, step: event.data.step,
+      time: event.time,
+      callView: view?.for === 'call' ? view.view : null,
+    })
+    // No backfill into already-materialized tool-result nodes for this callId
+    // (window order puts the call before its result; cannot happen on the normal path).
+  }
+}

packages/client/runtime/tests/compact-checkpoint-pin.spec.ts

@@ -0,0 +1,52 @@
+/**
+ * Drift trap for the compaction-checkpoint recognition rule.
+ *
+ * `TranscriptAdapter` restates the compaction seam's checkpoint source as a
+ * local literal because it cannot import `dsh-compact` in any form: a VALUE
+ * import fails the client purity gate, and a TYPE-ONLY import fails typecheck —
+ * `dsh-compact`'s root reaches `dsh-session`'s root, whose cordis `Context`
+ * merge declares the HOST `sessions: SessionStore` against the client program's
+ * `sessions: ISessions` (`TS2717`). This spec runs in the client TEST program,
+ * which does not carry that collision, and it is the only thing keeping the two
+ * implementations from drifting: it drives the adapter with a checkpoint built
+ * from the canonical `COMPACT_CHECKPOINT_SOURCE` itself, so renaming the seam's
+ * plugin fails HERE instead of silently deleting every compaction marker from
+ * the web transcript.
+ */
+
+import { COMPACT_CHECKPOINT_SOURCE, isCompactCheckpointSource } from '@deepseek-ai/dsh-compact'
+import { createUserMessage } from '@deepseek-ai/dsh-llm'
+import { describe, expect, it } from 'vitest'
+import type { SessionEvent } from '@deepseek-ai/dsh-session/types'
+import { TranscriptAdapter } from '../src/client/sessions/transcript-adapter.ts'
+
+/** A replacement user message stamped with the seam's own canonical source. */
+function canonicalCheckpoint(seq: number): SessionEvent {
+  return {
+    type: 'user/message',
+    seq,
+    time: 1_700_000_000_000 + seq,
+    surfaceOp: { op: 'replace', start: 0, end: 0 },
+    sourceEventSeqs: [0],
+    data: createUserMessage({
+      content: [{ type: 'text', text: '<context_checkpoint>model only</context_checkpoint>' }],
+      source: COMPACT_CHECKPOINT_SOURCE,
+    }),
+  } as unknown as SessionEvent
+}
+
+describe('compaction checkpoint recognition', () => {
+  it('recognizes a checkpoint carrying the seam-canonical source', () => {
+    const adapter = new TranscriptAdapter()
+    adapter.reset([canonicalCheckpoint(1)])
+    expect(adapter.nodes()).toEqual([{ kind: 'compaction', seq: 1, time: 1_700_000_000_001, summary: null }])
+  })
+
+  it('agrees with the seam s own predicate on the source it recognizes', () => {
+    // Both sides answer the same question about the same value: if the seam
+    // renames its plugin, this equality is what breaks.
+    const checkpoint = canonicalCheckpoint(1)
+    expect(checkpoint.type === 'user/message' && isCompactCheckpointSource(checkpoint.data.source)).toBe(true)
+    expect(COMPACT_CHECKPOINT_SOURCE).toEqual({ kind: 'plugin', plugin: 'compact' })
+  })
+})

packages/client/runtime/tests/event-script.ts

@@ -69,6 +69,27 @@ export const ev = {
     at(seq, { type: 'command/run', data: { commandId, name, args, source: { kind: 'user' } } }),
   commandDone: (seq: number, commandId: string, kind: 'success' | 'error' = 'success', text?: string): SessionEvent =>
     at(seq, { type: 'command/done', data: { commandId, kind, ...text === undefined ? {} : { text } } }),
+  /** A compaction's log-only `compact/summary` provenance record. */
+  compactSummary: (seq: number, summary: string, start: number, end: number): SessionEvent =>
+    at(seq, { type: 'compact/summary', data: {
+      summary: text(summary),
+      shadowedRange: { start, end },
+      shadowedSeqs: [start, end],
+      shadowedTokenCount: 100,
+      provider: 'fake',
+      model: 'compact-1',
+    } }),
+  /** The replacement user message a compaction backend lands (the checkpoint). */
+  compactCheckpoint: (seq: number, summarySeq: number, start: number, end: number): SessionEvent =>
+    at(seq, {
+      type: 'user/message',
+      surfaceOp: { op: 'replace', start, end },
+      sourceEventSeqs: [summarySeq, start, end],
+      data: createUserMessage({
+        content: text('<context_checkpoint>model only</context_checkpoint>'),
+        source: { kind: 'plugin', plugin: 'compact' },
+      }),
+    }),
 }
 
 /** One complete plain turn (turn/start → user → step → assistant → turn/end), 6 events from startSeq. */

packages/client/runtime/tests/fold-adapter.spec.ts

@@ -1,251 +0,0 @@
-import { createUserMessage, CallId, createMessage, createToolResultMessage } from '@deepseek-ai/dsh-llm'
-/**
- * FoldAdapter over the real core SurfaceManager: padding sentinels for paged
- * windows, incremental append with node-cache identity, six-variant
- * materialization, call-index backfill, and the degraded linear-scan branch.
- */
-
-import { describe, expect, it, vi } from 'vitest'
-import type { SessionEvent } from '@deepseek-ai/dsh-session/types'
-import { FoldAdapter } from '../src/client/sessions/fold-adapter.ts'
-import { ev, plainTurn } from './event-script.ts'
-
-const at = (seq: number, e: Record<string, unknown>): SessionEvent =>
-  ({ seq, time: 1_700_000_000_000 + seq, ...e }) as unknown as SessionEvent
-
-describe('FoldAdapter', () => {
-  it('folds a baseSeq>0 window through padding sentinels with correct seqs', () => {
-    const adapter = new FoldAdapter()
-    const window = plainTurn(100, 5, '偏移问', '偏移答')
-    adapter.reset(window, 100)
-    const { nodes, degraded } = adapter.nodes()
-    expect(degraded).toBe(false)
-    expect(nodes.map(n => [n.kind, n.seq])).toEqual([['user', 101], ['assistant', 103]])
-  })
-
-  it('appends incrementally keeping old node references (cache identity)', () => {
-    const adapter = new FoldAdapter()
-    adapter.reset(plainTurn(0, 0, 'a', 'b'), 0)
-    const first = adapter.nodes()
-    adapter.append(ev.user(6, '追加'))
-    const second = adapter.nodes()
-    expect(second.nodes).toHaveLength(3)
-    expect(second.nodes[0]).toBe(first.nodes[0])
-    expect(second.nodes[1]).toBe(first.nodes[1])
-    expect(second.nodes).not.toBe(first.nodes) // array itself fresh per call
-  })
-
-  it('materializes all six node variants with field mapping', () => {
-    const adapter = new FoldAdapter()
-    const events = [
-      ev.user(0, '用户'),
-      ev.assistant(1, 0, '助手'),
-      at(2, { type: 'steering/message', surfaceOp: 'append', data: {
-        turn: 0,
-        message: createUserMessage({
-          content: [{ type: 'text', text: '插话' }],
-          source: { kind: 'user' },
-        }),
-      } }),
-      at(3, { type: 'user/message', surfaceOp: 'append', data: createUserMessage({
-        content: [{ type: 'text', text: '上下文' }], source: { kind: 'plugin', plugin: 'p' },
-      }) }),
-      ev.toolCall(4, 0, 'c1', 'echo', '{"x":1}'),
-      ev.toolResult(5, 0, 'c1', '结果'),
-    ]
-    adapter.reset(events, 0)
-    const { nodes } = adapter.nodes()
-    const kinds = nodes.map(n => n.kind)
-    expect(kinds).toContain('user')
-    expect(kinds).toContain('assistant')
-    expect(kinds).toContain('steering')
-    expect(kinds).toContain('context')
-    const result = nodes.find(n => n.kind === 'tool-result')
-    expect(result).toMatchObject({ callId: 'c1', call: { name: 'echo', argsRaw: '{"x":1}' }, isError: false })
-  })
-
-  it('returns call:null for a tool-result whose call fell outside the window', () => {
-    const adapter = new FoldAdapter()
-    adapter.reset([ev.toolResult(50, 3, 'outside-call', '孤儿结果')], 50)
-    const { nodes } = adapter.nodes()
-    expect(nodes[0]).toMatchObject({ kind: 'tool-result', callId: 'outside-call', call: null })
-  })
-
-  it('materializes surface-eligible types it does not know as unknown nodes', () => {
-    const adapter = new FoldAdapter()
-    adapter.reset([at(0, { type: 'notice/message', surfaceOp: 'append', data: { note: 1 } })], 0)
-    const { nodes } = adapter.nodes()
-    // Either the fold surfaces it (unknown node) or skips it as non-eligible — both are valid
-    // shapes; what matters is no throw and no misclassification into a known kind.
-    for (const node of nodes) expect(node.kind).toBe('unknown')
-  })
-
-  it('degrades to the lenient linear scan when the fold throws, and stays degraded', () => {
-    const adapter = new FoldAdapter()
-    // An invalid surfaceOp on a surface-eligible event deterministically throws in the core fold.
-    const window = [
-      ev.user(10, '正常'),
-      at(11, { type: 'assistant/message', surfaceOp: 'bogus-op', data: {
-        turn: 0, step: 0,
-        message: createMessage({
-          role: 'assistant',
-          content: [{ type: 'text', text: '坏 op' }],
-          source: {
-            kind: 'model',
-            ...{ provider: 'x', model: 'y' },
-          },
-        }),
-      } }),
-    ]
-    const errorSpy = vi.spyOn(console, 'error').mockImplementation(() => undefined)
-    try {
-      adapter.reset(window, 10)
-      const first = adapter.nodes()
-      expect(first.degraded).toBe(true)
-      expect(errorSpy).toHaveBeenCalled()
-      expect(first.nodes.map(n => n.seq)).toEqual([10, 11]) // linear scan: append order, bad op ignored
-      adapter.append(ev.user(12, '降级后追加')) // bump rev so the cached result is not reused
-      const second = adapter.nodes()
-      expect(second.degraded).toBe(true) // sticky: no re-throw loop, straight to the linear scan
-      expect(second.nodes[0]).toBe(first.nodes[0]) // cache still serves node identity
-      expect(second.nodes.map(n => n.seq)).toEqual([10, 11, 12])
-    } finally {
-      errorSpy.mockRestore()
-    }
-  })
-
-  it('materializes a tool-result error field when present', () => {
-    const adapter = new FoldAdapter()
-    adapter.reset([
-      at(0, { type: 'tool/result', surfaceOp: 'append', data: {
-        turn: 0, step: 0,
-        message: createToolResultMessage({
-          callId: CallId('c1'),
-          content: [],
-          isError: true,
-        }),
-        error: { name: 'Boom', code: 'boom' },
-      } }),
-    ], 0)
-    expect(adapter.nodes().nodes[0]).toMatchObject({ kind: 'tool-result', isError: true, error: { code: 'boom' } })
-  })
-
-  it('exposes the in-window call index for runningCalls material', () => {
-    const adapter = new FoldAdapter()
-    adapter.reset([ev.toolCall(0, 1, 'c9', 'slow', '{}')], 0)
-    expect(adapter.callIndex.get('c9')).toMatchObject({ name: 'slow', turn: 1 })
-    adapter.append(ev.toolCall(1, 1, 'c10', 'fast', '{}'))
-    expect(adapter.callIndex.size).toBe(2)
-  })
-
-  it('attaches wire views: callView into the call index, resultView onto the node by seq', () => {
-    const adapter = new FoldAdapter()
-    const events = [
-      ev.toolCall(0, 1, 'c1', 'bash', '{"cmd":"ls"}'),
-      ev.toolResult(1, 1, 'c1', 'listing'),
-    ]
-    const callView = { for: 'call' as const, view: { card: 'terminal' as const, command: 'ls' } }
-    const resultView = { for: 'result' as const, view: { card: 'generic' as const, title: '完成' } }
-    adapter.reset(events, 0, [callView, resultView] as never)
-    expect(adapter.callIndex.get('c1')).toMatchObject({ callView: { card: 'terminal' } })
-    const node = adapter.nodes().nodes.find(n => n.kind === 'tool-result')
-    expect(node).toMatchObject({ callView: { card: 'terminal' }, resultView: { card: 'generic', title: '完成' } })
-  })
-
-  it('attaches views on the live append path and defaults to null without views', () => {
-    const adapter = new FoldAdapter()
-    adapter.reset(plainTurn(0, 0, 'a', 'b'), 0) // no views argument: legacy-shaped call
-    adapter.append(ev.toolCall(6, 1, 'c2', 'echo', '{}'), { for: 'call', view: { card: 'generic', title: '回声' } } as never)
-    adapter.append(ev.toolResult(7, 1, 'c2', 'ok')) // no view on the result
-    expect(adapter.callIndex.get('c2')).toMatchObject({ callView: { title: '回声' } })
-    const node = adapter.nodes().nodes.find(n => n.kind === 'tool-result')
-    expect(node).toMatchObject({ callView: { title: '回声' }, resultView: null })
-  })
-
-  it('leaves callView null when the paired call fell outside the window (cross-page break)', () => {
-    const adapter = new FoldAdapter()
-    const resultView = { for: 'result' as const, view: { card: 'generic' as const, title: '孤儿' } }
-    adapter.reset([ev.toolResult(50, 3, 'outside', '窗外配对')], 50, [resultView] as never)
-    const node = adapter.nodes().nodes[0]
-    expect(node).toMatchObject({ kind: 'tool-result', call: null, callView: null, resultView: { title: '孤儿' } })
-  })
-
-  describe('command lifecycle nodes', () => {
-    it('folds a run/done pair into one settled node merged into flow order by seq', () => {
-      const adapter = new FoldAdapter()
-      adapter.reset([
-        ev.user(0, '先说话'),
-        ev.commandRun(1, 'cmd-1', 'plan'),
-        ev.commandDone(2, 'cmd-1', 'success', '已进入 plan mode'),
-        ev.assistant(3, 0, '然后回答'),
-      ], 0)
-      const { nodes } = adapter.nodes()
-      expect(nodes.map(n => [n.kind, n.seq])).toEqual([['user', 0], ['command', 1], ['assistant', 3]])
-      expect(nodes[1]).toMatchObject({
-        kind: 'command', commandId: 'cmd-1', name: 'plan', args: '',
-        outcome: { kind: 'success', text: '已进入 plan mode' },
-      })
-    })
-
-    it('renders a run with no done as still executing (outcome null)', () => {
-      const adapter = new FoldAdapter()
-      adapter.reset([ev.commandRun(0, 'cmd-2', 'goal', ' ship it')], 0)
-      expect(adapter.nodes().nodes[0]).toMatchObject({
-        kind: 'command', name: 'goal', args: ' ship it', outcome: null,
-      })
-    })
-
-    it('soft-falls a done-only window into a node built from the done (cross-window cut)', () => {
-      const adapter = new FoldAdapter()
-      adapter.reset([ev.commandDone(80, 'cmd-3', 'error', '失败了')], 80)
-      expect(adapter.nodes().nodes[0]).toMatchObject({
-        kind: 'command', seq: 80, commandId: 'cmd-3', name: null, args: null,
-        outcome: { kind: 'error', text: '失败了' },
-      })
-    })
-
-    it('settles a live-appended done in place, keeping the node at the run seq', () => {
-      const adapter = new FoldAdapter()
-      adapter.reset(plainTurn(0, 0, 'q', 'a'), 0)
-      adapter.append(ev.commandRun(6, 'cmd-4', 'clear'))
-      const running = adapter.nodes().nodes.find(n => n.kind === 'command')
-      expect(running).toMatchObject({ outcome: null })
-      adapter.append(ev.commandDone(7, 'cmd-4'))
-      const settled = adapter.nodes().nodes.find(n => n.kind === 'command')
-      expect(settled).toMatchObject({ seq: 6, outcome: { kind: 'success' } })
-      // Settlement replaced the node object rather than mutating the published one.
-      expect(settled).not.toBe(running)
-    })
-
-    it('tails command nodes whose seq is past every surface node', () => {
-      const adapter = new FoldAdapter()
-      adapter.reset([ev.user(0, '问'), ev.commandRun(1, 'cmd-tail', 'plan')], 0)
-      expect(adapter.nodes().nodes.map(n => n.kind)).toEqual(['user', 'command'])
-    })
-
-    it('command nodes survive the degraded linear-scan branch', () => {
-      const adapter = new FoldAdapter()
-      const errorSpy = vi.spyOn(console, 'error').mockImplementation(() => undefined)
-      try {
-        adapter.reset([
-          ev.commandRun(0, 'cmd-5', 'plan'),
-          ev.commandDone(1, 'cmd-5'),
-          at(2, { type: 'assistant/message', surfaceOp: 'bogus-op', data: {
-            turn: 0,
-            step: 0,
-            message: createMessage({
-              role: 'assistant',
-              content: [{ type: 'text', text: '坏 op' }],
-              source: { kind: 'model', provider: 'x', model: 'y' },
-            }),
-          } }),
-        ], 0)
-        const { nodes, degraded } = adapter.nodes()
-        expect(degraded).toBe(true)
-        expect(nodes.some(n => n.kind === 'command')).toBe(true)
-      } finally {
-        errorSpy.mockRestore()
-      }
-    })
-  })
-})

packages/client/runtime/tests/session.spec.ts

@@ -195,6 +195,45 @@ describe('live event path', () => {
     })
   })
 
+  it('keeps compacted history and adds one marker, live and on replay alike', async () => {
+    // A landed compaction must not erase conversation the reader already saw:
+    // the shadowed messages stay at their own log positions and the checkpoint
+    // contributes one marker after them.
+    const { session } = await opened()
+    const feed = (event: SessionEvent) => { session.handleMuxEnvelope('r' as never, { type: 'session/event', sessionId: SID, event }) }
+    feed(ev.compactSummary(6, '压缩摘要', 1, 3))
+    feed(ev.compactCheckpoint(7, 6, 1, 3))
+    const live = session.getSnapshot().nodes
+    expect(live.map(n => [n.kind, n.seq])).toEqual([['user', 1], ['assistant', 3], ['compaction', 7]])
+    expect(live.at(-1)).toMatchObject({ kind: 'compaction', summary: '压缩摘要' })
+
+    const replayed = await opened([
+      ...plainTurn(0, 0, 'a', 'b'),
+      ev.compactSummary(6, '压缩摘要', 1, 3),
+      ev.compactCheckpoint(7, 6, 1, 3),
+    ])
+    expect(replayed.session.getSnapshot().nodes).toEqual(live)
+  })
+
+  it('merges an interrupted frozen node by seq into the log-ordered transcript', async () => {
+    // The transcript array is seq-monotonic, so the frozen node's fractional
+    // seq lands it exactly where it happened — including after a compaction
+    // checkpoint whose own seq is higher than the range it shadowed.
+    const { session } = await opened()
+    const feed = (event: SessionEvent) => { session.handleMuxEnvelope('r' as never, { type: 'session/event', sessionId: SID, event }) }
+    feed(ev.compactSummary(6, '压缩摘要', 1, 3))
+    feed(ev.compactCheckpoint(7, 6, 1, 3))
+    feed(ev.turnStart(8, 1))
+    feed(ev.user(9, '压缩后的提问'))
+    feed(ev.chunkStart(10, 1))
+    feed(ev.chunkText(11, 1, '说到一半'))
+    feed(ev.turnEnd(12, 1, 'cancelled'))
+    expect(session.getSnapshot().nodes.map(n => n.kind)).toEqual([
+      'user', 'assistant', 'compaction', 'user', 'assistant',
+    ])
+    expect(session.getSnapshot().nodes.at(-1)).toMatchObject({ interrupted: true })
+  })
+
   it('repairs a seq gap by repulling the tail page instead of appending a hole', async () => {
     const { api, session } = await opened(plainTurn(0, 0, 'a', 'b')) // tail seq = 5
     const repaired = [...plainTurn(0, 0, 'a', 'b'), ...plainTurn(6, 1, 'c', 'd')]
@@ -226,6 +265,30 @@ describe('paging', () => {
     expect(snapshot.nodes.map(n => n.seq)).toEqual([1, 3, 7, 9])
   })
 
+  it('renders a page whose checkpoint shadows seqs below the window head, logging nothing', async () => {
+    // Pagination no longer spends maxMessages quota on replacement copies, so a
+    // page can carry a compaction checkpoint whose surfaceOp.start lies outside
+    // the window. The old surface fold rejected that range and degraded with a
+    // console error; the log-ordered transcript has no range to resolve.
+    const { api, session } = makeSession()
+    api.onHistory = () => histResponse([
+      ev.compactSummary(80, '窗外范围的摘要', 3, 40),
+      ev.compactCheckpoint(81, 80, 3, 40),
+      ev.user(82, '压缩后的新问题'),
+    ], true)
+    const errorSpy = vi.spyOn(console, 'error').mockImplementation(() => undefined)
+    try {
+      await session.open()
+      const snapshot = session.getSnapshot()
+      expect(snapshot.openState).toBe('open')
+      expect(snapshot.nodes.map(n => [n.kind, n.seq])).toEqual([['compaction', 81], ['user', 82]])
+      expect(snapshot.nodes[0]).toMatchObject({ summary: '窗外范围的摘要' })
+      expect(errorSpy).not.toHaveBeenCalled()
+    } finally {
+      errorSpy.mockRestore()
+    }
+  })
+
   it('drops a discontinuous older page fail-soft (window unchanged, hasMore cleared)', async () => {
     const { api, session } = makeSession()
     api.onHistory = payload => payload.beforeSeq === undefined

packages/client/runtime/tests/transcript-adapter.spec.ts

@@ -0,0 +1,415 @@
+/**
+ * TranscriptAdapter over the raw append-only window: log-ordered projection of
+ * append-origin events, one marker per landed compaction, replacement copies
+ * hidden, command-lifecycle folding, node/array identity, call pairing, and
+ * host-provided wire views.
+ */
+
+import { createUserMessage, CallId, createMessage, createToolResultMessage } from '@deepseek-ai/dsh-llm'
+import { describe, expect, it } from 'vitest'
+import type { SessionEvent } from '@deepseek-ai/dsh-session/types'
+import { TranscriptAdapter } from '../src/client/sessions/transcript-adapter.ts'
+import { ev, plainTurn } from './event-script.ts'
+
+const at = (seq: number, e: Record<string, unknown>): SessionEvent =>
+  ({ seq, time: 1_700_000_000_000 + seq, ...e }) as unknown as SessionEvent
+
+/** A `compact/summary` provenance event (log-only, no surfaceOp). */
+function compactSummary(seq: number, summary: unknown = [{ type: 'text', text: '# 摘要\n\n保留事实' }]): SessionEvent {
+  return at(seq, {
+    type: 'compact/summary',
+    data: {
+      summary,
+      shadowedRange: { start: 1, end: 3 },
+      shadowedSeqs: [1, 3],
+      shadowedTokenCount: 100,
+      provider: 'fake',
+      model: 'compact-1',
+    },
+  })
+}
+
+/** The replacement user message a compaction backend lands (the checkpoint). */
+function checkpoint(
+  seq: number,
+  summarySeq: number,
+  { start = 1, end = 3, sourceEventSeqs = [summarySeq, start, end] }: {
+    start?: number
+    end?: number
+    sourceEventSeqs?: number[]
+  } = {},
+): SessionEvent {
+  return at(seq, {
+    type: 'user/message',
+    surfaceOp: { op: 'replace', start, end },
+    sourceEventSeqs,
+    data: createUserMessage({
+      content: [{ type: 'text', text: '<context_checkpoint>model only</context_checkpoint>' }],
+      source: { kind: 'plugin', plugin: 'compact' },
+    }),
+  })
+}
+
+describe('TranscriptAdapter', () => {
+  it('projects a window starting past seq 0 at its own log positions', () => {
+    const adapter = new TranscriptAdapter()
+    adapter.reset(plainTurn(100, 5, '偏移问', '偏移答'))
+    expect(adapter.nodes().map(n => [n.kind, n.seq])).toEqual([['user', 101], ['assistant', 103]])
+  })
+
+  it('appends incrementally keeping old node references (materialize-once identity)', () => {
+    const adapter = new TranscriptAdapter()
+    adapter.reset(plainTurn(0, 0, 'a', 'b'))
+    const first = adapter.nodes()
+    adapter.append(ev.user(6, '追加'))
+    const second = adapter.nodes()
+    expect(second).toHaveLength(3)
+    expect(second[0]).toBe(first[0])
+    expect(second[1]).toBe(first[1])
+    expect(second).not.toBe(first) // a real change swaps the array
+  })
+
+  it('keeps the array reference across a chunk storm and swaps it when a node lands', () => {
+    const adapter = new TranscriptAdapter()
+    adapter.reset(plainTurn(0, 0, 'a', 'b'))
+    const settled = adapter.nodes()
+    adapter.append(ev.chunkStart(6, 1))
+    expect(adapter.nodes()).toBe(settled)
+    adapter.append(ev.chunkText(7, 1, '流式'))
+    expect(adapter.nodes()).toBe(settled)
+    adapter.append(ev.assistant(8, 1, '流式完成'))
+    const finalized = adapter.nodes()
+    expect(finalized).not.toBe(settled)
+    expect(finalized.at(-1)).toMatchObject({ kind: 'assistant', seq: 8 })
+  })
+
+  it('materializes every append-origin variant with field mapping', () => {
+    const adapter = new TranscriptAdapter()
+    adapter.reset([
+      ev.user(0, '用户'),
+      ev.assistant(1, 0, '助手'),
+      at(2, { type: 'steering/message', surfaceOp: 'append', data: {
+        turn: 0,
+        message: createUserMessage({
+          content: [{ type: 'text', text: '插话' }],
+          source: { kind: 'user' },
+        }),
+      } }),
+      at(3, { type: 'user/message', surfaceOp: 'append', data: createUserMessage({
+        content: [{ type: 'text', text: '上下文' }], source: { kind: 'plugin', plugin: 'p' },
+      }) }),
+      ev.toolCall(4, 0, 'c1', 'echo', '{"x":1}'),
+      ev.toolResult(5, 0, 'c1', '结果'),
+    ])
+    const nodes = adapter.nodes()
+    expect(nodes.map(n => n.kind)).toEqual(['user', 'assistant', 'steering', 'context', 'tool-result'])
+    expect(nodes.find(n => n.kind === 'tool-result')).toMatchObject({
+      callId: 'c1', call: { name: 'echo', argsRaw: '{"x":1}' }, isError: false,
+    })
+  })
+
+  it('skips events core does not call surface-eligible, marker or not', () => {
+    // The transcript is the append-origin surface, so log-only events (a chunk,
+    // a turn boundary, a compact/* provenance record) and a future type core
+    // has not admitted contribute no node.
+    const adapter = new TranscriptAdapter()
+    adapter.reset([
+      ev.turnStart(0, 1),
+      at(1, { type: 'notice/message', surfaceOp: 'append', data: { note: 1 } }),
+      compactSummary(2),
+      ev.user(3, '唯一的一条'),
+      ev.turnEnd(4, 1),
+    ])
+    expect(adapter.nodes().map(n => [n.kind, n.seq])).toEqual([['user', 3]])
+  })
+
+  describe('compaction markers', () => {
+    it('keeps the original messages and full tool output, hiding replacement copies', () => {
+      const adapter = new TranscriptAdapter()
+      adapter.reset([
+        ev.user(0, '原始问题'),
+        ev.assistant(1, 0, '原始回答'),
+        ev.toolCall(4, 0, 'c1', 'echo', '{}'),
+        ev.toolResult(5, 0, 'c1', '完整工具输出'),
+        // A pruned tool/result copy: rewrites one node for the model, marks nothing.
+        at(6, { type: 'tool/result', surfaceOp: { op: 'replace', start: 5, end: 5 }, sourceEventSeqs: [5], data: {
+          turn: 0, step: 0,
+          message: createToolResultMessage({ callId: CallId('c1'), content: [{ type: 'text', text: '已裁剪' }], isError: false }),
+        } }),
+        compactSummary(7),
+        checkpoint(8, 7, { start: 1, end: 5, sourceEventSeqs: [7, 1, 5] }),
+        // A regenerated assistant/message: also a silent model-only rewrite.
+        at(9, { type: 'assistant/message', surfaceOp: { op: 'replace', start: 8, end: 8 }, sourceEventSeqs: [8], data: {
+          turn: 0, step: 0,
+          message: createMessage({
+            role: 'assistant',
+            content: [{ type: 'text', text: '通用 replacement 副本' }],
+            source: { kind: 'model', ...{ provider: 'x', model: 'copy' } },
+          }),
+        } }),
+      ])
+      const nodes = adapter.nodes()
+      expect(nodes.map(n => [n.kind, n.seq])).toEqual([
+        ['user', 0], ['assistant', 1], ['tool-result', 5], ['compaction', 8],
+      ])
+      expect(nodes[2]).toMatchObject({ kind: 'tool-result', content: [{ type: 'text', text: '完整工具输出' }] })
+      expect(nodes[3]).toMatchObject({ kind: 'compaction', summary: '# 摘要\n\n保留事实' })
+    })
+
+    it('adds one marker per landed compaction, in log order', () => {
+      const adapter = new TranscriptAdapter()
+      adapter.reset([
+        ev.user(0, 'a'),
+        compactSummary(1, [{ type: 'text', text: 'first' }]),
+        checkpoint(2, 1, { start: 0, end: 0, sourceEventSeqs: [1, 0] }),
+        ev.user(3, 'b'),
+        compactSummary(4, [{ type: 'text', text: 'second' }]),
+        checkpoint(5, 4, { start: 2, end: 3, sourceEventSeqs: [4, 2, 3] }),
+      ])
+      expect(adapter.nodes().filter(n => n.kind === 'compaction')).toEqual([
+        { kind: 'compaction', seq: 2, time: 1_700_000_000_002, summary: 'first' },
+        { kind: 'compaction', seq: 5, time: 1_700_000_000_005, summary: 'second' },
+      ])
+    })
+
+    it('renders the marker when the shadowed range is outside the window and logs nothing', () => {
+      // The pagination hole A1 left open: quota is no longer spent on
+      // replacement copies, so a page can carry a checkpoint whose
+      // surfaceOp.start lies below the window head. The old surface fold threw
+      // on the missing range and degraded with a console error; a log-ordered
+      // projection has no range to resolve.
+      const adapter = new TranscriptAdapter()
+      const noise = { error: console.error, warn: console.warn }
+      const logged: unknown[] = []
+      console.error = (...args: unknown[]) => logged.push(args)
+      console.warn = (...args: unknown[]) => logged.push(args)
+      try {
+        adapter.reset([
+          compactSummary(80, [{ type: 'text', text: '窗外范围' }]),
+          checkpoint(81, 80, { start: 3, end: 40, sourceEventSeqs: [80, 3, 40] }),
+          ev.user(82, '压缩后的新问题'),
+        ])
+        expect(adapter.nodes().map(n => [n.kind, n.seq])).toEqual([['compaction', 81], ['user', 82]])
+        expect(adapter.nodes()[0]).toMatchObject({ summary: '窗外范围' })
+      } finally {
+        console.error = noise.error
+        console.warn = noise.warn
+      }
+      expect(logged).toEqual([])
+    })
+
+    it('treats an APPENDING plugin-sourced user/message as injected context, not a compaction', () => {
+      // A session-reference card carries the same plugin source shape; only the
+      // replacement marker makes an event a checkpoint.
+      const adapter = new TranscriptAdapter()
+      adapter.reset([
+        at(0, { type: 'user/message', surfaceOp: 'append', data: createUserMessage({
+          content: [{ type: 'text', text: '注入的上下文' }],
+          source: { kind: 'plugin', plugin: 'compact' },
+        }) }),
+      ])
+      expect(adapter.nodes()).toMatchObject([{ kind: 'context', seq: 0 }])
+    })
+
+    it('ignores a foreign plugin s replacement user/message', () => {
+      const adapter = new TranscriptAdapter()
+      adapter.reset([
+        ev.user(0, '保留'),
+        at(1, { type: 'user/message', surfaceOp: { op: 'replace', start: 0, end: 0 }, sourceEventSeqs: [0], data: createUserMessage({
+          content: [{ type: 'text', text: '别的插件重写' }],
+          source: { kind: 'plugin', plugin: 'not-compact' },
+        }) }),
+      ])
+      expect(adapter.nodes().map(n => [n.kind, n.seq])).toEqual([['user', 0]])
+    })
+
+    it.each([
+      ['absent provenance', undefined],
+      ['malformed summary blocks', compactSummary(1, [{ type: 'image', data: 'nope' }])],
+      ['a whitespace-only summary', compactSummary(1, [{ type: 'text', text: '   ' }])],
+      ['an empty summary array', compactSummary(1, [])],
+      ['a non-array summary', compactSummary(1, 'plain string')],
+    ])('degrades %s to a non-expandable marker', (_label, summary) => {
+      const adapter = new TranscriptAdapter()
+      adapter.reset([
+        ...(summary === undefined ? [] : [summary]),
+        checkpoint(2, 1, { start: 0, end: 0, sourceEventSeqs: [1, 0] }),
+      ])
+      expect(adapter.nodes()).toEqual([
+        { kind: 'compaction', seq: 2, time: 1_700_000_000_002, summary: null },
+      ])
+    })
+
+    it('leaves the summary null when the checkpoint records no provenance at all', () => {
+      const adapter = new TranscriptAdapter()
+      adapter.reset([at(2, {
+        type: 'user/message',
+        surfaceOp: { op: 'replace', start: 0, end: 0 },
+        data: createUserMessage({
+          content: [{ type: 'text', text: '<context_checkpoint>x</context_checkpoint>' }],
+          source: { kind: 'plugin', plugin: 'compact' },
+        }),
+      })])
+      expect(adapter.nodes()).toEqual([{ kind: 'compaction', seq: 2, time: 1_700_000_000_002, summary: null }])
+    })
+
+    it('skips a non-summary provenance seq before reaching the real one', () => {
+      const adapter = new TranscriptAdapter()
+      adapter.reset([
+        ev.user(0, '被压缩的问题'),
+        at(1, { type: 'compact/start', data: { turn: 0 } }),
+        compactSummary(2, [{ type: 'text', text: '第三个来源才是摘要' }]),
+        checkpoint(3, 2, { start: 0, end: 0, sourceEventSeqs: [1, 2, 0] }),
+      ])
+      expect(adapter.nodes().at(-1)).toMatchObject({ kind: 'compaction', summary: '第三个来源才是摘要' })
+    })
+
+    it('resolves the summary once an older page supplies the provenance', () => {
+      const adapter = new TranscriptAdapter()
+      const landed = checkpoint(8, 7, { start: 0, end: 0, sourceEventSeqs: [7, 0] })
+      adapter.reset([landed])
+      expect(adapter.nodes()[0]).toMatchObject({ kind: 'compaction', summary: null })
+      adapter.reset([compactSummary(7, [{ type: 'text', text: '分页补齐的摘要' }]), landed])
+      expect(adapter.nodes()[0]).toMatchObject({ kind: 'compaction', summary: '分页补齐的摘要' })
+    })
+
+    it('creates the marker on the live append path', () => {
+      const adapter = new TranscriptAdapter()
+      adapter.reset(plainTurn(0, 0, 'a', 'b'))
+      adapter.append(compactSummary(6, [{ type: 'text', text: '直播摘要' }]))
+      adapter.append(checkpoint(7, 6, { start: 1, end: 3, sourceEventSeqs: [6, 1, 3] }))
+      const nodes = adapter.nodes()
+      // The compacted history is still there; the marker is one more row after it.
+      expect(nodes.map(n => [n.kind, n.seq])).toEqual([['user', 1], ['assistant', 3], ['compaction', 7]])
+      expect(nodes.at(-1)).toMatchObject({ kind: 'compaction', seq: 7, summary: '直播摘要' })
+    })
+  })
+
+  it('returns call:null for a tool-result whose call fell outside the window', () => {
+    const adapter = new TranscriptAdapter()
+    adapter.reset([ev.toolResult(50, 3, 'outside-call', '孤儿结果')])
+    expect(adapter.nodes()[0]).toMatchObject({ kind: 'tool-result', callId: 'outside-call', call: null })
+  })
+
+  it('materializes a tool-result error field when present', () => {
+    const adapter = new TranscriptAdapter()
+    adapter.reset([
+      at(0, { type: 'tool/result', surfaceOp: 'append', data: {
+        turn: 0, step: 0,
+        message: createToolResultMessage({ callId: CallId('c1'), content: [], isError: true }),
+        error: { name: 'Boom', code: 'boom' },
+      } }),
+    ])
+    expect(adapter.nodes()[0]).toMatchObject({ kind: 'tool-result', isError: true, error: { code: 'boom' } })
+  })
+
+  it('exposes the in-window call index for runningCalls material', () => {
+    const adapter = new TranscriptAdapter()
+    adapter.reset([ev.toolCall(0, 1, 'c9', 'slow', '{}')])
+    expect(adapter.callIndex.get('c9')).toMatchObject({ name: 'slow', turn: 1 })
+    adapter.append(ev.toolCall(1, 1, 'c10', 'fast', '{}'))
+    expect(adapter.callIndex.size).toBe(2)
+  })
+
+  it('attaches wire views: callView into the call index, resultView onto the node by seq', () => {
+    const adapter = new TranscriptAdapter()
+    const callView = { for: 'call' as const, view: { card: 'terminal' as const, command: 'ls' } }
+    const resultView = { for: 'result' as const, view: { card: 'generic' as const, title: '完成' } }
+    adapter.reset([
+      ev.toolCall(0, 1, 'c1', 'bash', '{"cmd":"ls"}'),
+      ev.toolResult(1, 1, 'c1', 'listing'),
+    ], [callView, resultView] as never)
+    expect(adapter.callIndex.get('c1')).toMatchObject({ callView: { card: 'terminal' } })
+    expect(adapter.nodes().find(n => n.kind === 'tool-result')).toMatchObject({
+      callView: { card: 'terminal' }, resultView: { card: 'generic', title: '完成' },
+    })
+  })
+
+  it('attaches views on the live append path and defaults to null without views', () => {
+    const adapter = new TranscriptAdapter()
+    adapter.reset(plainTurn(0, 0, 'a', 'b')) // no views argument
+    adapter.append(ev.toolCall(6, 1, 'c2', 'echo', '{}'), { for: 'call', view: { card: 'generic', title: '回声' } } as never)
+    adapter.append(ev.toolResult(7, 1, 'c2', 'ok')) // no view on the result
+    expect(adapter.callIndex.get('c2')).toMatchObject({ callView: { title: '回声' } })
+    expect(adapter.nodes().find(n => n.kind === 'tool-result')).toMatchObject({
+      callView: { title: '回声' }, resultView: null,
+    })
+  })
+
+  it('leaves callView null when the paired call fell outside the window (cross-page break)', () => {
+    const adapter = new TranscriptAdapter()
+    const resultView = { for: 'result' as const, view: { card: 'generic' as const, title: '孤儿' } }
+    adapter.reset([ev.toolResult(50, 3, 'outside', '窗外配对')], [resultView] as never)
+    expect(adapter.nodes()[0]).toMatchObject({
+      kind: 'tool-result', call: null, callView: null, resultView: { title: '孤儿' },
+    })
+  })
+
+  describe('command lifecycle nodes', () => {
+    it('folds a run/done pair into one settled node merged into flow order by seq', () => {
+      const adapter = new TranscriptAdapter()
+      adapter.reset([
+        ev.user(0, '先说话'),
+        ev.commandRun(1, 'cmd-1', 'plan'),
+        ev.commandDone(2, 'cmd-1', 'success', '已进入 plan mode'),
+        ev.assistant(3, 0, '然后回答'),
+      ])
+      const nodes = adapter.nodes()
+      expect(nodes.map(n => [n.kind, n.seq])).toEqual([['user', 0], ['command', 1], ['assistant', 3]])
+      expect(nodes[1]).toMatchObject({
+        kind: 'command', commandId: 'cmd-1', name: 'plan', args: '',
+        outcome: { kind: 'success', text: '已进入 plan mode' },
+      })
+    })
+
+    it('renders a run with no done as still executing (outcome null)', () => {
+      const adapter = new TranscriptAdapter()
+      adapter.reset([ev.commandRun(0, 'cmd-2', 'goal', ' ship it')])
+      expect(adapter.nodes()[0]).toMatchObject({ kind: 'command', name: 'goal', args: ' ship it', outcome: null })
+    })
+
+    it('soft-falls a done-only window into a node built from the done (cross-window cut)', () => {
+      const adapter = new TranscriptAdapter()
+      adapter.reset([ev.commandDone(80, 'cmd-3', 'error', '失败了')])
+      expect(adapter.nodes()[0]).toMatchObject({
+        kind: 'command', seq: 80, commandId: 'cmd-3', name: null, args: null,
+        outcome: { kind: 'error', text: '失败了' },
+      })
+    })
+
+    it('settles a live-appended done in place, keeping the node at the run seq', () => {
+      const adapter = new TranscriptAdapter()
+      adapter.reset(plainTurn(0, 0, 'q', 'a'))
+      adapter.append(ev.commandRun(6, 'cmd-4', 'clear'))
+      const running = adapter.nodes().find(n => n.kind === 'command')
+      expect(running).toMatchObject({ outcome: null })
+      adapter.append(ev.commandDone(7, 'cmd-4'))
+      const settled = adapter.nodes().find(n => n.kind === 'command')
+      expect(settled).toMatchObject({ seq: 6, outcome: { kind: 'success' } })
+      // Settlement replaced the node object rather than mutating the published one.
+      expect(settled).not.toBe(running)
+    })
+
+    it('tails command nodes whose seq is past every transcript node', () => {
+      const adapter = new TranscriptAdapter()
+      adapter.reset([ev.user(0, '问'), ev.commandRun(1, 'cmd-tail', 'plan')])
+      expect(adapter.nodes().map(n => n.kind)).toEqual(['user', 'command'])
+    })
+
+    it('renders the /compact row alongside the marker its own command produced', () => {
+      // The row that reports the compaction is a command node; dropping command
+      // folding would delete it together with every other slash-command row.
+      const adapter = new TranscriptAdapter()
+      adapter.reset([
+        ev.user(0, '压缩前的问题'),
+        ev.commandRun(1, 'cmd-compact', 'compact'),
+        compactSummary(2, [{ type: 'text', text: '手动压缩摘要' }]),
+        checkpoint(3, 2, { start: 0, end: 0, sourceEventSeqs: [2, 0] }),
+        ev.commandDone(4, 'cmd-compact', 'success', '已压缩'),
+      ])
+      const nodes = adapter.nodes()
+      expect(nodes.map(n => [n.kind, n.seq])).toEqual([['user', 0], ['command', 1], ['compaction', 3]])
+      expect(nodes[1]).toMatchObject({ name: 'compact', outcome: { kind: 'success', text: '已压缩' } })
+    })
+  })
+})

packages/client/test-runtime/src/fixtures.ts

@@ -46,7 +46,6 @@ export function conversationSnapshot(sessionId: SessionId): ConversationSnapshot
   return {
     sessionId,
     nodes: [],
-    foldDegraded: false,
     partial: null,
     runningCalls: [],
     codeDispatches: new Map(),

packages/client/ui-conversation/src/client/chat/CompactionItem.tsx

@@ -0,0 +1,49 @@
+// CompactionItem: the one row a landed compaction contributes to the flow.
+// The conversation it shadowed on the model surface stays above it, so this
+// marker reports where the model stopped seeing that history — it never
+// replaces it. The framed checkpoint payload is written for the model and is
+// not rendered; the disclosure shows the summary from the checkpoint's own
+// provenance, and a window cut that left that provenance outside makes the row
+// non-expandable rather than empty.
+
+import { memo, useState } from 'react'
+import type { CompactionSummaryNode } from '@deepseek-ai/dsh-client-runtime/client'
+import {
+  IconChevronDownOutline14,
+  IconChevronRightOutline14,
+  MarkdownText,
+} from '@deepseek-ai/dsh-client-ui-primitives'
+import css from './MessageItem.module.css'
+
+/**
+ * The collapsed-by-default compaction marker.
+ * @param props - the marker node off the snapshot cache.
+ * @returns the marker row, with the summary disclosure when one is available.
+ */
+export const CompactionItem = memo(function CompactionItem({ node }: { node: CompactionSummaryNode }) {
+  const [expanded, setExpanded] = useState(false)
+  const expandable = node.summary !== null
+  const open = expandable && expanded
+  return (
+    <div className={css.compactionRow}>
+      <button
+        type="button"
+        className={css.compactionButton}
+        disabled={!expandable}
+        aria-expanded={expandable ? open : undefined}
+        onClick={() => { setExpanded(value => !value) }}
+      >
+        <span className={css.compactionLeading}>
+          {open ? <IconChevronDownOutline14 /> : <IconChevronRightOutline14 />}
+        </span>
+        <span className={css.compactionTitle}>上下文已压缩</span>
+        <span className={css.compactionSep} aria-hidden />
+        <span className={css.compactionSummary}>
+          {expandable ? '点击查看压缩摘要' : '压缩摘要不可用'}
+        </span>
+      </button>
+      {open && node.summary !== null
+        && <div className={css.compactionBody}><MarkdownText text={node.summary} /></div>}
+    </div>
+  )
+})

packages/client/ui-conversation/src/client/chat/MessageItem.module.css

@@ -42,6 +42,81 @@
   padding: 2px 0;
 }
 
+/* Compaction marker: one dim 24px row with a chevron disclosure for the
+   summary body. Dimmed title (not label-primary) — the row is a boundary
+   notice, not conversation content. */
+.compactionRow {
+  padding: 2px 0;
+}
+
+.compactionButton {
+  display: flex;
+  align-items: center;
+  width: 100%;
+  height: 24px;
+  min-width: 0;
+  padding: 0;
+  border: none;
+  border-radius: 6px;
+  background: none;
+  color: inherit;
+  font: inherit;
+  text-align: left;
+}
+
+.compactionButton:not(:disabled) {
+  cursor: pointer;
+}
+
+.compactionButton:not(:disabled):hover {
+  background: var(--dsw-alias-interactive-bg-hover);
+}
+
+.compactionLeading {
+  flex: none;
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  width: 16px;
+  height: 16px;
+  margin-right: 6px;
+  color: var(--dsw-alias-label-secondary);
+}
+
+.compactionTitle {
+  flex: none;
+  font-size: 14px;
+  line-height: 24px;
+  color: var(--dsw-alias-label-primary-dimmed);
+}
+
+.compactionSep {
+  flex: none;
+  width: 2px;
+  height: 2px;
+  margin: 0 8px;
+  border-radius: 1px;
+  background: var(--dsw-alias-label-caption);
+}
+
+.compactionSummary {
+  flex: 1 1 auto;
+  min-width: 0;
+  overflow: hidden;
+  color: var(--dsw-alias-label-tertiary);
+  font-size: 14px;
+  line-height: 24px;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.compactionBody {
+  padding: 4px 0 4px 22px;
+  color: var(--dsw-alias-label-tertiary);
+  font-size: 14px;
+  line-height: 24px;
+}
+
 /* Reference chip projection inside a user bubble (`<skill>name</skill>` model
    spans render as chips; free geometry — no textarea pairing here). */
 .refChip {

packages/client/ui-conversation/src/client/chat/MessageItem.tsx

@@ -1,20 +1,21 @@
-// MessageItem: the four simple node kinds — user bubble (right-aligned, with
+// MessageItem: the five simple node kinds — user bubble (right-aligned, with
 // clock + copy / branch / edit IconActions), steering (badged bubble), context
-// injection and unknown-surface JSON rows. Props are frozen node slices off
-// the snapshot cache; memo holds across streaming because unchanged nodes
-// keep their references.
+// injection, the compaction marker, and unknown-surface JSON rows. Props are
+// frozen node slices off the snapshot cache; memo holds across streaming
+// because unchanged nodes keep their references.
 
 import { memo } from 'react'
 import type { ReactNode } from 'react'
 import type {
-  ContextMessageNode, SteeringMessageNode, UnknownSurfaceNode, UserMessageNode,
+  CompactionSummaryNode, ContextMessageNode, SteeringMessageNode, UnknownSurfaceNode, UserMessageNode,
 } from '@deepseek-ai/dsh-client-runtime/client'
 import { JsonBlock, MessageText } from '@deepseek-ai/dsh-client-ui-primitives'
+import { CompactionItem } from './CompactionItem.tsx'
 import { MessageIconActions } from './MessageIconActions.tsx'
 import css from './MessageItem.module.css'
 
 export interface MessageItemProps {
-  node: UserMessageNode | SteeringMessageNode | ContextMessageNode | UnknownSurfaceNode
+  node: UserMessageNode | SteeringMessageNode | ContextMessageNode | CompactionSummaryNode | UnknownSurfaceNode
 }
 
 function contentText(content: readonly unknown[]): { text: string; rest: unknown[] } {
@@ -98,6 +99,8 @@ export const MessageItem = memo(function MessageItem({ node }: MessageItemProps)
           <JsonBlock label="上下文注入" payload={{ content: node.content, source: node.source }} />
         </div>
       )
+    case 'compaction':
+      return <CompactionItem node={node} />
     default:
       return (
         <div className={css.contextRow}>

packages/client/ui-conversation/src/client/chat/chat-flow.ts

@@ -24,7 +24,7 @@ function rendersNothing(node: ConversationNode): boolean {
 
 /**
  * Group finalized nodes into the step-summary flow.
- * @param nodes - snapshot nodes (surface order).
+ * @param nodes - snapshot nodes (human transcript order).
  * @returns flow items; consecutive tool-results merged into one group keyed by the first seq.
  */
 export function deriveChatFlow(nodes: readonly ConversationNode[]): ChatFlowItem[] {

packages/client/ui-conversation/tests/chat-branch-tails.spec.tsx

@@ -117,6 +117,34 @@ describe('MessageItem arms', () => {
     )
     expect(unknownView.getByText(/未知 surface 事件：surface\/next/)).toBeTruthy()
   })
+
+  it('a compaction marker discloses its summary and never shows the framed checkpoint', () => {
+    const view = render(
+      <MessageItem node={{
+        kind: 'compaction', seq: 5, time: 1_000,
+        summary: '## 摘要标题\n\n保留的事实。',
+      }}
+      />,
+    )
+    const row = view.getByRole('button', { name: /上下文已压缩/ })
+    expect(row.getAttribute('aria-expanded')).toBe('false')
+    expect(view.queryByText(/保留的事实/)).toBeNull()
+    fireEvent.click(row)
+    expect(row.getAttribute('aria-expanded')).toBe('true')
+    expect(view.getByRole('heading', { name: '摘要标题' })).toBeTruthy()
+    fireEvent.click(row)
+    expect(row.getAttribute('aria-expanded')).toBe('false')
+  })
+
+  it('a marker whose provenance fell outside the window is not expandable', () => {
+    const view = render(<MessageItem node={{ kind: 'compaction', seq: 6, time: 1_000, summary: null }} />)
+    const row = view.getByRole('button', { name: /上下文已压缩/ })
+    expect(row).toHaveProperty('disabled', true)
+    expect(row.getAttribute('aria-expanded')).toBeNull()
+    expect(view.getByText('压缩摘要不可用')).toBeTruthy()
+    fireEvent.click(row) // a disabled control stays collapsed
+    expect(row.getAttribute('aria-expanded')).toBeNull()
+  })
 })
 
 describe('formatMessageClock', () => {

packages/client/ui-conversation/tests/chat-code-subcalls.spec.tsx

@@ -55,7 +55,7 @@ function snapshotWith(
   runningCalls: RunningToolCall[] = [],
 ): ConversationSnapshot {
   return {
-    sessionId: SID, nodes, foldDegraded: false, partial: null, runningCalls, codeDispatches,
+    sessionId: SID, nodes, partial: null, runningCalls, codeDispatches,
     pending: [], queue: [], running: runningCalls.length > 0, composerPhase: 'active', removed: false,
     openState: 'open', openError: null,
     hasMore: false, loadingOlder: false, promptError: null, blank: false, lastAgentError: null,

packages/client/ui-conversation/tests/chat-stats-bash-sample.spec.tsx

@@ -26,7 +26,7 @@ const assistant = (seq: number, turn: number, usage?: unknown): AssistantMessage
 
 function snapshotBase(): ConversationSnapshot {
   return {
-    sessionId: SID, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
+    sessionId: SID, nodes: [], partial: null, runningCalls: [], codeDispatches: new Map(),
     pending: [], queue: [], running: false, composerPhase: 'active', removed: false, openState: 'open', openError: null,
     hasMore: false, loadingOlder: false, promptError: null, blank: false, lastAgentError: null,
   }

packages/client/ui-conversation/tests/chat-view.spec.tsx

@@ -29,7 +29,7 @@ const SID = 's1' as SessionId
 
 function snapshotBase(): ConversationSnapshot {
   return {
-    sessionId: SID, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
+    sessionId: SID, nodes: [], partial: null, runningCalls: [], codeDispatches: new Map(),
     pending: [], queue: [], running: false, composerPhase: 'active', removed: false, openState: 'open', openError: null,
     hasMore: false, loadingOlder: false, promptError: null, blank: false, lastAgentError: null,
   }

packages/client/ui-conversation/tests/gate-branch-tails.spec.tsx

@@ -18,7 +18,7 @@ const SID = 's1' as SessionId
 
 function snapshotBase(): ConversationSnapshot {
   return {
-    sessionId: SID, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
+    sessionId: SID, nodes: [], partial: null, runningCalls: [], codeDispatches: new Map(),
     pending: [], queue: [], running: false, composerPhase: 'active', removed: false, openState: 'open', openError: null,
     hasMore: false, loadingOlder: false, promptError: null, blank: false, lastAgentError: null,
   }

packages/client/ui-conversation/tests/input-bar.spec.tsx

@@ -20,7 +20,7 @@ const SID = 's1' as SessionId
 
 function snapshotOf(overrides: Partial<ConversationSnapshot> = {}): ConversationSnapshot {
   return {
-    sessionId: SID, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
+    sessionId: SID, nodes: [], partial: null, runningCalls: [], codeDispatches: new Map(),
     pending: [], queue: [], running: false, composerPhase: 'active', removed: false,
     openState: 'open', openError: null, hasMore: false, loadingOlder: false,
     promptError: null, blank: false, lastAgentError: null,

packages/client/ui-conversation/tests/input-matrix.spec.tsx

@@ -23,7 +23,7 @@ const SID = 's1' as SessionId
 /** Standard-props InputBar mount over a real shell (the composer-bar entry shape). */
 function mountBar(shell: SessionInputShell, over?: { running?: boolean; disabled?: boolean }) {
   const session = createSnapshotStore<ConversationSnapshot>({
-    sessionId: SID, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
+    sessionId: SID, nodes: [], partial: null, runningCalls: [], codeDispatches: new Map(),
     pending: [], queue: [], running: over?.running ?? false, composerPhase: 'active',
     removed: over?.disabled ?? false, openState: 'open', openError: null, hasMore: false,
     loadingOlder: false, promptError: null, blank: false, lastAgentError: null,

packages/client/ui-conversation/tests/input-scenarios.spec.tsx

@@ -109,7 +109,7 @@ async function scopedBench(register?: (slash: SlashService) => void) {
   actx.on('slash/input-consume-token', req => shell.consumeToken(req.guard) ? true : undefined)
   const wiring = shell
   const sessionStore = createSnapshotStore<ConversationSnapshot>({
-    sessionId, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
+    sessionId, nodes: [], partial: null, runningCalls: [], codeDispatches: new Map(),
     pending: [], queue: [], running: false, composerPhase: 'active', removed: false,
     openState: 'open', openError: null, hasMore: false, loadingOlder: false,
     promptError: null, blank: false, lastAgentError: null,

packages/client/ui-conversation/tests/queue-dock.spec.tsx

@@ -18,7 +18,7 @@ const SID = 's1' as SessionId
 
 function snapshotWith(queue: QueuedMessage[]): ConversationSnapshot {
   return {
-    sessionId: SID, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
+    sessionId: SID, nodes: [], partial: null, runningCalls: [], codeDispatches: new Map(),
     pending: [], queue, running: true, composerPhase: 'active', removed: false, openState: 'open', openError: null,
     hasMore: false, loadingOlder: false, promptError: null, blank: false, lastAgentError: null,
   }

packages/client/ui-conversation/tests/skeleton.spec.tsx

@@ -47,7 +47,7 @@ const workspaceState = (items: readonly WorkspaceView[]): WorkspaceListState =>
 
 function conversationSnapshot(overrides: Partial<ConversationSnapshot> = {}): ConversationSnapshot {
   return {
-    sessionId: SID, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
+    sessionId: SID, nodes: [], partial: null, runningCalls: [], codeDispatches: new Map(),
     pending: [], queue: [], running: false, composerPhase: 'active', removed: false,
     openState: 'open', openError: null, hasMore: false, loadingOlder: false,
     promptError: null, blank: false, lastAgentError: null,

packages/client/ui-trajectory/src/client/layout.ts

@@ -110,8 +110,8 @@ export function deriveTrajectoryLayout(input: TrajectoryLayoutInput): readonly T
       lastAssistantTurn = node.turn
       continue
     }
-    if (node.kind === 'context') {
-      // No trajectory cell, but the surface still advances the duration cursor.
+    if (node.kind === 'context' || node.kind === 'compaction') {
+      // No trajectory cell, but transcript metadata still advances the duration cursor.
       prevAbsTime = finiteTime(node.time) ?? prevAbsTime
       continue
     }

packages/client/ui-trajectory/src/client/spans.ts

@@ -45,7 +45,7 @@ export interface SpanStats {
  * Fold snapshot nodes into per-turn spans. Only assistant nodes carry a turn
  * number; user/steering/context/tool nodes attach to the turn last seen in
  * sequence order (turn 0 collects the pre-assistant prologue).
- * @param nodes - snapshot nodes in surface order.
+ * @param nodes - snapshot nodes in human transcript order.
  * @returns spans ordered by first appearance.
  */
 export function deriveSpans(nodes: ConversationSnapshot['nodes']): readonly TurnSpan[] {

packages/client/ui-trajectory/tests/layout.spec.tsx

@@ -176,7 +176,7 @@ describe('deriveTrajectoryLayout', () => {
     })
   })
 
-  it('advances the duration cursor over context nodes', () => {
+  it('advances the duration cursor over context and compaction nodes', () => {
     const nodes = [
       { kind: 'user', seq: 1, time: 1_000, content: [{ type: 'text', text: 'hi' }], source: null },
       {
@@ -192,17 +192,21 @@ describe('deriveTrajectoryLayout', () => {
         kind: 'context', seq: 4, time: 9_000,
         content: [{ type: 'text', text: 'extra' }], source: null,
       },
+      // A landed compaction renders no cell either, but is still a real log
+      // position, so it moves the cursor the same way a context row does.
+      { kind: 'compaction', seq: 5, time: 9_500, summary: 'checkpoint facts' },
       {
-        kind: 'assistant', seq: 5, time: 10_000, turn: 1, step: 0,
+        kind: 'assistant', seq: 6, time: 10_000, turn: 1, step: 0,
         blocks: [{ kind: 'text', text: 'done' }],
       },
     ] as unknown as ConversationSnapshot['nodes']
     const turns = deriveTrajectoryLayout({ codeDispatches: new Map(), nodes, partial: null, runningCalls: [] })
-    const message = turns[0]?.groups
-      .flatMap(g => g.cells)
-      .find(c => c.kind === 'message' && c.text === 'done')
-    // From context at 9s, not from the earlier user/tool surfaces.
-    expect(message?.timeSeconds).toBe(1)
+    const cells = turns[0]?.groups.flatMap(g => g.cells) ?? []
+    const message = cells.find(c => c.kind === 'message' && c.text === 'done')
+    // From the compaction marker at 9.5s, not from context at 9s or the earlier surfaces.
+    expect(message?.timeSeconds).toBe(0.5)
+    // Neither the context row nor the marker contributed a cell.
+    expect(cells).toHaveLength(3)
   })
 })
 

pnpm-lock.yaml

@@ -956,6 +956,9 @@ importers:
         specifier: ~4.4.7
         version: 4.4.7(@types/react@18.3.31)(immer@10.2.0)(react@18.3.1)
     devDependencies:
+      '@deepseek-ai/dsh-compact':
+        specifier: workspace:^
+        version: link:../../compact/compact
       '@deepseek-ai/dsh-invariants':
         specifier: workspace:^
         version: link:../../support/invariants

tsconfig.client.json

@@ -36,6 +36,12 @@
     // client-side Context merges keep it out of the host program.
     { "path": "./packages/host/directory-picker-native" },
     { "path": "./packages/host/directory-picker-browse" },
+    // Test-only leaf: the client-runtime drift trap for the compaction
+    // checkpoint source reads the seam's canonical const. It may appear HERE
+    // but never in a packages/client/* package project — dsh-compact's root
+    // reaches dsh-session's root, whose Context merge declares the host
+    // `sessions: SessionStore` and collides with the client's `ISessions`.
+    { "path": "./packages/compact/compact" },
     { "path": "./packages/client/ui-slots" },
     { "path": "./packages/client/ui-primitives" },
     { "path": "./packages/client/web-react" },