Merge remote-tracking branch 'origin/master' into codex/unify-landlock-release

2026-08-06 12:01:52 +08:00
parent 32864c026c 0865926c38
commit d1a8a79ed0
259 changed files with 7952 additions and 2004 deletions
@@ -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/architecture/2026-06-14-session-persistence.md
-2026-06-14-session-persistence.md: 137b2b01126214629952812f3dd3b71985a3acda
-2026-06-14-session-persistence.zh.md: 0f00902f5d6d60073bb56aabaf420bf2042e08fc
+2026-06-14-session-persistence.md: 00e129e57c7144fd62eec26f5854ee21dec4e964
+2026-06-14-session-persistence.zh.md: 1c98d5771819e8776d9f5cae4a147d2016ee5978
@@ -14,23 +14,23 @@ The [event-sourced model](2026-06-11-event-sourced-sessions.md) makes the append

 Persistence is an abstract **capability seam** ([capability seams](2026-06-13-capability-seams.md), the `dsh-bash` template), not loop or core logic:

-1. **Interface** (`dsh-session-persistence`, `ctx.sessionPersistence`) — an abstract `SessionPersistence` service: `create`/`append`/`load`/`list`. Its persisted unit IS the existing `SessionEvent` (`{ type, seq, time, data }`), reused verbatim — no conversion type.
+1. **Interface** (`dsh-session-persistence`, `ctx.sessionPersistence`) — an abstract `SessionPersistence` service: `locate`/`create`/`append`/`prepare`/`load`/`inspect`/`readFrom`/`list`/`listSnapshots`. Its persisted unit IS the existing `SessionEvent` (`{ type, seq, time, data }`), reused verbatim — no conversion type.
 2. **Implementation** (`dsh-session-persistence-jsonl`) — an append-only logical JSONL log per session: a `SessionHeader` line followed by storage records that losslessly represent the contiguous `SessionEvent` stream. Eligible `assistant/chunk` delta runs use packed rows by default; [checksummed Zstandard frames](2026-07-19-zstandard-jsonl-session-logs.md) are the default physical encoding, with raw lines configurable.

 Key choices recorded here because they are durable, contested, and surprising:

- **The canonical durable log persists every `SessionEvent` losslessly, including `assistant/chunk`.** JSONL storage may encode a consecutive delta run as one packed row, but `load` reconstructs the exact event boundaries, sequence numbers, and timestamps. `deriveMessages()` skips chunks, and a chunk-filtered rollout (Codex's `policy.rs`) is tempting — but `seq = log.length` and the load-validation `events[i].seq === i` require a *contiguous* logical log; filtering chunks out would leave holes and break both the contract and resume. A chunk-filtered projection is possible later as a derived view with its own renumbering, but it is NOT the canonical log.
- **Append-only; a crashed turn is closed, never truncated.** Flushed events are never rewritten. The [semantic checkpoint policy](../bug-fix/2026-07-21-semantic-session-checkpoints.md) drains the request before model dispatch, a recorded top-level call before tool dispatch, and the complete response/result batch after a step; the loop drains the final turn boundary. Because one interrupted turn may contain substantial valid work, `load` preserves its contiguous, parseable events and appends risk-classified error results for unanswered assistant calls, a missing `step/end`, and `turn/end` with `{ kind: 'interrupted' }`. The synthetic results keep resumed provider transcripts valid. Only an incomplete final record is discarded; a parse error or sequence gap at or before the last real `turn/end` is corruption and makes the session unloadable.
- **File backend canonical, DB backend a proven drop-in.** `SessionEvent` maps 1:1 onto a row `(session_id, seq, type, time, data)` — `append` is INSERT (in a transaction asserting the contiguous-seq contract), `load` is SELECT … ORDER BY seq. `dsh-session-persistence-sqlite` is exactly this: a `SessionPersistence` subclass with no interface change (opencode runs this exact shape on SQLite/WAL), and it passes the same `runPersistenceContract` suite as the JSONL backend — so the contract holds both backends to identical semantics (lazy materialization, interrupted-turn close on load, contiguous-seq), expressed once over file bytes and once over rows. Its database carries a dedicated application id and monotonic schema version. A pristine file creates all tables and stamps both header values in one transaction; an unversioned file with any user-defined schema object or application identity, a foreign current-version identity, and every non-current version reject before journal-mode mutation.
+- **The canonical durable log persists every `SessionEvent` losslessly, including `assistant/chunk`.** JSONL storage may encode a consecutive delta run as one packed row, but logical readers reconstruct the exact event boundaries, sequence numbers, and timestamps. `deriveMessages()` skips chunks, and a chunk-filtered rollout (Codex's `policy.rs`) is tempting — but `seq = log.length` and validation of `events[i].seq === i` require a *contiguous* logical log; filtering chunks out would leave holes and break both the contract and resume. A chunk-filtered projection is possible later as a derived view with its own renumbering, but it is NOT the canonical log.
+- **Append-only; a crashed turn is closed, never truncated.** Flushed events are never rewritten. The [semantic checkpoint policy](../bug-fix/2026-07-21-semantic-session-checkpoints.md) drains the request before model dispatch, a recorded top-level call before tool dispatch, and the complete response/result batch after a step; the loop drains the final turn boundary. Because one interrupted turn may contain substantial valid work, cold inspection preserves its contiguous, parseable events and adds risk-classified error results for unanswered assistant calls, a missing `step/end`, and `turn/end` with `{ kind: 'interrupted' }` to the in-memory logical view. `prepare` or `load` commits those closers before returning a recoverable view; the synthetic results keep resumed provider transcripts valid. Only an incomplete final record is discarded during committed repair; a parse error or sequence gap at or before the last real `turn/end` is corruption and makes the session unloadable.
+- **File backend canonical, DB backend a proven drop-in.** `SessionEvent` maps 1:1 onto a row `(session_id, seq, type, time, data)` — `append` is INSERT (in a transaction asserting the contiguous-seq contract), and reads use SELECT … ORDER BY seq. `dsh-session-persistence-sqlite` is exactly this: a `SessionPersistence` subclass with no interface change (opencode runs this exact shape on SQLite/WAL), and it passes the same `runPersistenceContract` suite as the JSONL backend — so the contract holds both backends to identical semantics (lazy materialization, logical interrupted-turn closure, single committed repair, contiguous-seq), expressed once over file bytes and once over rows. Its database carries a dedicated application id and monotonic schema version. A pristine file creates all tables and stamps both header values in one transaction; an unversioned file with any user-defined schema object or application identity, a foreign current-version identity, and every non-current version reject before journal-mode mutation.
 - **Metadata is out-of-log.** Format version, cwd, and lineage are storage concerns, not replayable conversation state, so they live in a `SessionHeader` owned by `dsh-session` and attached to a `Session` via a new readonly `session.header` — never in `SessionEventMap`, never reaching `deriveMessages()`. `createdAt` is non-negative safe-integer Unix epoch milliseconds: live creation and persistence registration reject fractional values, JSONL validates the decoded header, and SQLite stores it in a strict `INTEGER` column. The alternative (a merge-extensible `session/meta` event as log line 0) was rejected: an in-log event would ride along with a seeded/forked session for free, but metadata is not replayable state, so the explicit out-of-log header seam is the cleaner cost. (The header was originally split into an immutable `SessionHeader` plus a mutable `SessionSummary` whose union was `SessionMeta`; the mutable summary was later removed as dead state — see [Drop the mutable session summary](../simplification/2026-06-19-drop-mutable-session-summary.md).)
- **`ctx.agents.create()` and `ctx.agents.resume()` are async factories; resume additionally crosses the persistence boundary.** `ctx.agents.resume({ resumeSessionId })` awaits `ctx.sessionPersistence.load`, recreates the live session with the loaded events (so `lastTurnNumber`/`deriveMessages` continue), and registers the fresh agent under the exact resumed id. The agent-loop does NOT hard-inject `sessionPersistence` (that would pend non-persistent demos forever); `resume` rejects with a clear error when it is absent.
+- **`ctx.agents.create()` and `ctx.agents.resume()` are async factories; resume additionally crosses the persistence boundary.** `ctx.agents.resume({ resumeSessionId })` obtains the exact unpublished Session through `ctx.sessionPersistence.prepare()`, publishes it under the persisted id, and continues its projections. The [Session preparation decision](2026-08-05-session-preparation.md) owns reuse between history inspection and resume. The agent-loop does NOT hard-inject `sessionPersistence` (that would pend non-persistent demos forever); `resume` rejects with a clear error when it is absent.

 ## Alternatives considered

 Each key choice above records its rejected alternative where the choice is stated: a **chunk-filtered canonical log** (Codex's `policy.rs` shape) — breaks the contiguous-seq contract; **truncating a crashed turn** — silently destroys a long autonomous run's real work; an **in-log `session/meta` event as line 0** — metadata is not replayable state; **finite fractional `createdAt` values** — have no producer and diverge from integer Unix-millisecond storage and query columns; **adopting a non-pristine unversioned SQLite file** — can overwrite unrelated objects or identity; **hard-injecting `sessionPersistence` into the loop** — would pend non-persistent demos forever.

-Format versioning: the header carries a `version`; `load` rejects any non-current version. The pre-release session format stays pinned at `SESSION_FORMAT_VERSION = 0` and carries no broad compatibility promise, while the coordinator may own an explicit narrow import upgrade when persisted user data requires it ([pre-identity message recovery](../bug-fix/2026-07-28-load-pre-identity-session-messages.md)). Stated honestly: append-only + flush is robust to partial trailing writes (tolerated on load) but not to fsync-less power loss mid-line; a DB/WAL backend is the stronger option later.
+Format versioning: the header carries a `version`; cold reads reject any non-current version. The pre-release session format stays pinned at `SESSION_FORMAT_VERSION = 0` and carries no broad compatibility promise, while the coordinator may own an explicit narrow import upgrade when persisted user data requires it ([pre-identity message recovery](../bug-fix/2026-07-28-load-pre-identity-session-messages.md)). Stated honestly: append-only + flush is robust to partial trailing writes (tolerated during cold preparation) but not to fsync-less power loss mid-line; a DB/WAL backend is the stronger option later.

 ## Consequences

-Two new packages and the metadata seam in `dsh-session` (`session.header`, the `create(id?, options?)` signature). Bought: durable resume/fork, a read/replay path, crash tolerance, and host-side session access over the existing event-sourced log, with the backend swappable behind one interface. The reusable `runPersistenceContract` suite holds every backend to the same append-only, contiguous-seq, lazy-materialization, integer-metadata, and serializability semantics. Persisting the full logical log also settles event fidelity: every `assistant/chunk` survives exactly even when JSONL packs several into one storage row. SQLite initialization either commits its complete owned schema and header identity or leaves no partial schema to strand on the next open.
+Two new packages and the metadata seam in `dsh-session` (`session.header`, the `create(id?, options?)` signature). Bought: durable resume/fork, a read/replay path, crash tolerance, and host-side session access over the existing event-sourced log, with the backend swappable behind one interface. The reusable `runPersistenceContract` suite holds every backend to the same append-only, contiguous-seq, lazy-materialization, logical-recovery, integer-metadata, and serializability semantics. Persisting the full logical log also settles event fidelity: every `assistant/chunk` survives exactly even when JSONL packs several into one storage row. SQLite initialization either commits its complete owned schema and header identity or leaves no partial schema to strand on the next open.
@@ -14,23 +14,23 @@ Status: implemented

 持久化是一个抽象的**能力 seam**（[能力 seam](2026-06-13-capability-seams.md)，`dsh-bash` 模板），而非循环或核心逻辑：

-1. **接口**（`dsh-session-persistence`，`ctx.sessionPersistence`）：一个抽象的 `SessionPersistence` 服务，提供 `create`/`append`/`load`/`list`。其持久化单元就是现有的 `SessionEvent`（`{ type, seq, time, data }`），原样复用，无转换类型。
+1. **接口**（`dsh-session-persistence`，`ctx.sessionPersistence`）：一个抽象的 `SessionPersistence` 服务，提供 `locate`/`create`/`append`/`prepare`/`load`/`inspect`/`readFrom`/`list`/`listSnapshots`。其持久化单元就是现有的 `SessionEvent`（`{ type, seq, time, data }`），原样复用，无转换类型。
 2. **实现**（`dsh-session-persistence-jsonl`）：每个会话一个仅追加的逻辑 JSONL 日志：先是一行 `SessionHeader`，随后是无损表示连续 `SessionEvent` 流的存储记录。符合条件的 `assistant/chunk` 增量连续段默认使用打包行；[带校验和的 Zstandard 帧](2026-07-19-zstandard-jsonl-session-logs.md)是默认物理编码，也可通过配置使用原始行。

 以下关键选择记录于此，因为它们长期有效、存在争议且出人意料：

- **规范的持久日志无损保留每个 `SessionEvent`，包括 `assistant/chunk`。** JSONL 存储可以将一段连续的增量事件编码为一条打包行，但 `load` 会重建精确的事件边界、序号与时间戳。`deriveMessages()` 跳过分片，而过滤分片的方案（Codex 的 `policy.rs`）很有吸引力，但 `seq = log.length` 以及加载验证 `events[i].seq === i` 要求*连续*的逻辑日志；过滤掉分片会留下空洞，同时破坏契约和恢复功能。基于分片过滤的投影可以作为派生视图在后续实现（带有自己的重新编号），但它不是规范日志。
- **仅追加；崩溃的轮次被关闭，而非截断。** 已刷写的事件永不被重写。[语义检查点策略](../bug-fix/2026-07-21-semantic-session-checkpoints.md)会在模型分发前排空请求、在工具分发前排空已记录的顶层调用，并在步骤结束后排空完整的响应/结果批次；循环则排空最终轮次边界。由于一个被中断的轮次可能包含大量有效工作，`load` 保留其连续、可解析的事件，并为未应答的 assistant 调用追加按风险分类的错误结果、补一个缺失的 `step/end`，以及带 `{ kind: 'interrupted' }` 的 `turn/end`。合成的结果保证恢复后的提供方 transcript（文本记录）仍然有效。只有不完整的最后一条记录会被丢弃；在最后一个真实 `turn/end` 处或之前出现解析错误或序号间隙，属于数据损坏，会使该会话不可加载。
- **文件后端为规范实现，数据库后端为经过验证的直接替换。** `SessionEvent` 1:1 映射到一行 `(session_id, seq, type, time, data)`：`append` 是 INSERT（在一个断言连续 seq 契约的事务中），`load` 是 SELECT … ORDER BY seq。`dsh-session-persistence-sqlite` 正是如此：一个 `SessionPersistence` 子类，接口无变化（opencode 在 SQLite/WAL 上运行的正是这个形状），且通过与 JSONL 后端相同的 `runPersistenceContract` 测试套件。该契约以相同的语义约束两个后端（惰性物化、加载时关闭中断轮次、连续 seq），一次表达在文件字节上，一次表达在数据库行上。其数据库拥有专用的 application id 与单调递增的 schema 版本。系统会在一个事务中为全新文件创建所有表并写入这两个 header 值；未版本化文件若带有任何用户定义的 schema 对象或应用标识、当前版本文件若带有外部应用标识，以及任何非当前版本文件，都会在修改日志模式之前被拒绝。
+- **规范的持久日志无损保留每个 `SessionEvent`，包括 `assistant/chunk`。** JSONL 存储可以将一段连续的增量事件编码为一条打包行，但逻辑读取方会重建精确的事件边界、序号与时间戳。`deriveMessages()` 跳过分片，而过滤分片的方案（Codex 的 `policy.rs`）很有吸引力，但 `seq = log.length` 以及 `events[i].seq === i` 验证要求*连续*的逻辑日志；过滤掉分片会留下空洞，同时破坏契约和恢复功能。基于分片过滤的投影可以作为派生视图在后续实现（带有自己的重新编号），但它不是规范日志。
+- **仅追加；崩溃的轮次被关闭，而非截断。** 已刷写的事件永不被重写。[语义检查点策略](../bug-fix/2026-07-21-semantic-session-checkpoints.md)会在模型分发前排空请求、在工具分发前排空已记录的顶层调用，并在步骤结束后排空完整的响应/结果批次；循环则排空最终轮次边界。由于一个被中断的轮次可能包含大量有效工作，冷检查会保留其连续、可解析的事件，并在内存逻辑视图中为未应答的 assistant 调用添加按风险分类的错误结果、补一个缺失的 `step/end`，以及带 `{ kind: 'interrupted' }` 的 `turn/end`。`prepare` 或 `load` 在返回可恢复视图前提交这些 closer；合成结果保证恢复后的提供方 transcript（文本记录）仍然有效。只有不完整的最后一条记录会在提交修复时被丢弃；在最后一个真实 `turn/end` 处或之前出现解析错误或序号间隙，属于数据损坏，会使该会话不可加载。
+- **文件后端为规范实现，数据库后端为经过验证的直接替换。** `SessionEvent` 1:1 映射到一行 `(session_id, seq, type, time, data)`：`append` 是 INSERT（在一个断言连续 seq 契约的事务中），读取使用 SELECT … ORDER BY seq。`dsh-session-persistence-sqlite` 正是如此：一个 `SessionPersistence` 子类，接口无变化（opencode 在 SQLite/WAL 上运行的正是这个形状），且通过与 JSONL 后端相同的 `runPersistenceContract` 测试套件。该契约以相同的语义约束两个后端（惰性物化、逻辑关闭中断轮次、修复只提交一次、连续 seq），一次表达在文件字节上，一次表达在数据库行上。其数据库拥有专用的 application id 与单调递增的 schema 版本。系统会在一个事务中为全新文件创建所有表并写入这两个 header 值；未版本化文件若带有任何用户定义的 schema 对象或应用标识、当前版本文件若带有外部应用标识，以及任何非当前版本文件，都会在修改日志模式之前被拒绝。
 - **元数据在日志之外。** 格式版本、cwd 和谱系是存储关注点，不是可回放的对话状态，因此它们存放在 `dsh-session` 拥有的 `SessionHeader` 中，并通过新的只读属性 `session.header` 附加到 `Session` 上——永远不进入 `SessionEventMap`，永远不到达 `deriveMessages()`。`createdAt` 是以 Unix epoch 毫秒表示的非负安全整数：运行时创建和持久化注册会拒绝小数值，JSONL 会验证解码后的 header，SQLite 则将其存入严格的 `INTEGER` 列。替代方案（一个可合并扩展的 `session/meta` 事件作为日志第 0 行）被否决：日志内事件会自然随 seed/fork 的会话携带，但元数据不是可回放状态，因此显式的日志外 header seam 是更清晰的取舍。（header 最初被拆分为不可变的 `SessionHeader` 加可变的 `SessionSummary`，二者的联合类型为 `SessionMeta`；可变 summary 后来因属于死状态而被移除——见 [移除可变会话摘要](../simplification/2026-06-19-drop-mutable-session-summary.md)。）
- **`ctx.agents.create()` 和 `ctx.agents.resume()` 是异步工厂；恢复还跨越持久化边界。** `ctx.agents.resume({ resumeSessionId })` 等待 `ctx.sessionPersistence.load`，用加载的事件重建活跃会话（使 `lastTurnNumber`/`deriveMessages` 得以延续），并以原样恢复的 id 注册新 agent。agent loop（智能体循环）不会硬注入 `sessionPersistence`（那样会让非持久化的演示永远挂起）；当它不存在时，`resume` 会以明确的错误拒绝。
+- **`ctx.agents.create()` 和 `ctx.agents.resume()` 是异步工厂；恢复还跨越持久化边界。** `ctx.agents.resume({ resumeSessionId })` 通过 `ctx.sessionPersistence.prepare()` 取得精确的未发布 Session，以持久化 id 发布它，并继续其投影。[Session 准备阶段决策](2026-08-05-session-preparation.md)定义历史检查与恢复之间的复用。agent loop（智能体循环）不会硬注入 `sessionPersistence`（那样会让非持久化的演示永远挂起）；当它不存在时，`resume` 会以明确的错误拒绝。

 ## 曾考虑的替代方案

 上述每个关键选择都在陈述处记录了被否决的替代方案：**过滤分片的规范日志**（Codex 的 `policy.rs` 形式）破坏连续 seq 契约；**截断崩溃的轮次**会静默销毁长时间自主运行中的真实工作；**日志内 `session/meta` 事件作为第 0 行**——元数据不是可回放状态；**有限的非整数 `createdAt` 值**没有生产方，且与整数 Unix 毫秒存储及查询列不一致；**接受非全新的未版本化 SQLite 文件**可能覆盖无关对象或应用标识；**将 `sessionPersistence` 硬注入循环**会让非持久化的演示永远挂起。

-格式版本控制：header 携带一个 `version`；`load` 拒绝任何非当前版本。预发布阶段的会话格式仍固定为 `SESSION_FORMAT_VERSION = 0`，不承诺广泛兼容；当持久化用户数据确有需要时，协调器可以负责显式且范围受限的导入升级（[消息标识机制引入前的消息恢复](../bug-fix/2026-07-28-load-pre-identity-session-messages.md)）。坦率地说：仅追加 + 刷写对部分尾部写入是健壮的（加载时容忍），但对行写入中途的无 fsync 断电不健壮；数据库/WAL 后端是后续更强的选项。
+格式版本控制：header 携带一个 `version`；冷读取拒绝任何非当前版本。预发布阶段的会话格式仍固定为 `SESSION_FORMAT_VERSION = 0`，不承诺广泛兼容；当持久化用户数据确有需要时，协调器可以负责显式且范围受限的导入升级（[消息标识机制引入前的消息恢复](../bug-fix/2026-07-28-load-pre-identity-session-messages.md)）。坦率地说：仅追加 + 刷写对部分尾部写入是健壮的（冷准备时容忍），但对行写入中途的无 fsync 断电不健壮；数据库/WAL 后端是后续更强的选项。

 ## 后果

-新增两个包，以及 `dsh-session` 中的元数据 seam（`session.header`，`create(id?, options?)` 签名）。收益：持久恢复/fork、读取/回放路径、崩溃容忍，以及基于现有事件溯源日志的宿主侧会话访问，后端可在同一接口下替换。可复用的 `runPersistenceContract` 测试套件以相同的仅追加、连续 seq、惰性物化、整数元数据与可序列化语义约束每个后端。持久化完整的逻辑日志还确定了事件保真度：即使 JSONL 将多个 `assistant/chunk` 打包到一条存储行中，每个事件也会精确保留。SQLite 初始化要么提交完整的自有 schema 与 header 标识，要么不留下任何会使下次打开受阻的部分 schema。
+新增两个包，以及 `dsh-session` 中的元数据 seam（`session.header`，`create(id?, options?)` 签名）。收益：持久恢复/fork、读取/回放路径、崩溃容忍，以及基于现有事件溯源日志的宿主侧会话访问，后端可在同一接口下替换。可复用的 `runPersistenceContract` 测试套件以相同的仅追加、连续 seq、惰性物化、逻辑恢复、整数元数据与可序列化语义约束每个后端。持久化完整的逻辑日志还确定了事件保真度：即使 JSONL 将多个 `assistant/chunk` 打包到一条存储行中，每个事件也会精确保留。SQLite 初始化要么提交完整的自有 schema 与 header 标识，要么不留下任何会使下次打开受阻的部分 schema。
@@ -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/architecture/2026-06-18-shared-persistence-write-coordinator.md
-2026-06-18-shared-persistence-write-coordinator.md: 4632351a6f39c44c9ba8af58d508d4665b9e9279
-2026-06-18-shared-persistence-write-coordinator.zh.md: f5a70d7d6e7ab76663620ca8d416c671f81e2f8f
+2026-06-18-shared-persistence-write-coordinator.md: 66b73b60ceec9497f1f1226747b8cebd831eb426
+2026-06-18-shared-persistence-write-coordinator.zh.md: 424ce6ec7384e8af7b979a29f58c31379a1d1850
@@ -10,9 +10,9 @@ English | [中文](2026-06-18-shared-persistence-write-coordinator.zh.md)

 ## Decision

-Extract a backend-agnostic `PersistenceCoordinator` into `dsh-session-persistence`. The coordinator owns the orchestration once; each first-party backend composes one (`new PersistenceCoordinator(ctx, this)`), implements a small `PersistenceBackend` hook interface, and delegates its stateful public methods (`create`/`append`/`load`/`inspect`) to it. Backend-owned metadata and revision listing bypass the coordinator.
+Extract a backend-agnostic `PersistenceCoordinator` into `dsh-session-persistence`. The coordinator owns the orchestration once; each first-party backend composes one (`new PersistenceCoordinator(ctx, this)`), implements a small `PersistenceBackend` hook interface, and delegates its stateful public methods (`create`/`append`/`prepare`/`load`/`inspect`/`readFrom`) to it. Backend-owned metadata and revision listing bypass the coordinator.

-Composition, not inheritance. The coordinator is a concrete class the backend holds, not a base class the backend extends. The Agent Note's risk — "a coordinator must not make unusual backends fight an inheritance hierarchy" — is avoided: a backend exposes only the hooks and cannot reach the coordinator's private orchestration state. A third-party backend MAY still implement the abstract service directly without the coordinator, including the non-mutating `inspect` contract used by read models.
+Composition, not inheritance. The coordinator is a concrete class the backend holds, not a base class the backend extends. The Agent Note's risk — "a coordinator must not make unusual backends fight an inheritance hierarchy" — is avoided: a backend exposes only the hooks and cannot reach the coordinator's private orchestration state. A third-party backend MAY still implement the abstract service directly without the coordinator, including immutable logical inspection and the default preparation fallback through `load`.

 The coordinator holds one controller for each exact live `Session`; the controller combines initialization, pending events, and the shared flush promise. Each `session/event` starts an eager drain, and `session/flush` observes quiescence rather than initiating the ordinary write path. The [flush-controller simplification](../simplification/2026-07-23-collapse-persistence-flush-state.md) owns this lifecycle.

@@ -23,9 +23,9 @@ The coordinator retires a session from `session/disposed`: it waits for the cont
 Five required members plus an optional lifecycle hook form the only boundary between the coordinator and storage:

 - `name` — backend label for the dispose-failure `AggregateError`.
- `loadStored(id)` — read one stored prefix by id across every storage scope (every JSONL project directory; SQLite's id is globally unique). Resume/load, non-mutating inspection, live adoption, and the create-collision probe share this lookup. The coordinator asserts the returned id and rejects a stored/live cwd mismatch before repair or state publication.
+- `loadStored(id)` — read one stored prefix by id across every storage scope (every JSONL project directory; SQLite's id is globally unique). Preparation, logical load/inspection, physical suffix reads, live adoption, and the create-collision probe share this lookup. The coordinator asserts the returned id and rejects a stored/live cwd mismatch before repair or state publication.
 - `appendBatch(meta, events, isMaterialized)` — durably append a contiguous batch, lazily materializing the session ATOMICALLY when not yet materialized (the materialize-write and the first event batch must commit together — a crash between them must not leave a materialized-but-empty session; this is why there is no separate `materialize` hook).
- `commitRepair(meta, tornMarker, closers)` — make a crash repair durable: truncate the torn tail (iff `tornMarker !== undefined`) and append `closers`. **NOT required to be atomic** — JSONL legitimately truncates-then-appends in two fsync'd steps, SQLite does DELETE+INSERT in one transaction. Used by `load` (truncate + synthetic closers) and live-adoption (truncate only, `closers = []`).
+- `commitRepair(meta, tornMarker, closers)` — make a crash repair durable: truncate the torn tail (iff `tornMarker !== undefined`) and append `closers`. **NOT required to be atomic** — JSONL legitimately truncates-then-appends in two fsync'd steps, SQLite does DELETE+INSERT in one transaction. Used by `prepare`/`load` (truncate + synthetic closers) and live-adoption (truncate only, `closers = []`).
 - `list()` — list all stored metadata.
 - `close?()` — optional lifecycle teardown (SQLite closes its db handle; JSONL omits it), awaited in the dispose effect AFTER the quiescence drain so a close failure never masks a drain error.

@@ -35,7 +35,7 @@ The single design choice that keeps the seam clean: the crash-repair "where is t

 ## Testing

-The shared `runPersistenceContract` (public-API contract) runs for every backend and proves that `inspect` leaves interrupted logs and revisions unchanged before `load` performs recovery. `runCoordinatorContract` (`tests/coordinator-contract.ts`) covers adoption, HMR, collision, session and backend disposal drains, and crash-tail repair through an in-memory reference, JSONL, and SQLite. Coordinator-specific tests cover eager follow-up batches, live-controller cleanup, same-id chain-tail races, failed-drain retry, and close ordering. The per-backend specs retain storage mechanics only. A through-coordinator torn-tail repair test per real backend keeps the opaque-marker branch covered because the contract crash case produces synthetic closers without a torn marker.
+The shared `runPersistenceContract` (public-API contract) runs for every backend and proves that `inspect` balances an interrupted logical view without changing storage or revisions before `prepare` or `load` commits recovery. `runCoordinatorContract` (`tests/coordinator-contract.ts`) covers adoption, HMR, collision, session and backend disposal drains, and crash-tail repair through an in-memory reference, JSONL, and SQLite. `persistence.spec.ts` and `preparations.spec.ts` cover preparation reuse and reservation, bounded prepared-state eviction, eager follow-up batches, live-controller cleanup, same-id chain-tail races, failed-drain retry, and close ordering. The per-backend specs retain storage mechanics only. A through-coordinator torn-tail repair test per real backend keeps the opaque-marker branch covered because the contract crash case produces synthetic closers without a torn marker.

 ## Alternatives considered

@@ -44,4 +44,4 @@ The shared `runPersistenceContract` (public-API contract) runs for every backend

 ## Consequences

-The coordinator adds one indirection, an opaque torn marker, and detached session-retirement tasks, but centralizes correctness-heavy orchestration previously duplicated by every backend. Session disposal remains an observe-only event, so the session owner does not await persistence retirement; the coordinator contains failures, preserves pending events in the live controller, and makes backend teardown the quiescence boundary. Its hook surface stays narrow: identity, adoption, collision checks, and non-mutating inspection reuse `loadStored`; materialization stays atomic inside `appendBatch`; and listing bypasses the coordinator. Read models use `inspect` rather than `load`, so observing a persisted open turn cannot race a new live owner by committing interruption closers. New backends implement storage primitives rather than copy the eager write lifecycle.
+The coordinator adds one indirection, an opaque torn marker, detached session-retirement tasks, and bounded prepared Session state, but centralizes correctness-heavy orchestration previously duplicated by every backend. Session disposal remains an observe-only event, so the session owner does not await persistence retirement; the coordinator contains failures, preserves pending events in the live controller, and makes backend teardown the quiescence boundary. Its hook surface stays narrow: identity, adoption, collision checks, preparation, and immutable inspection reuse `loadStored`; materialization stays atomic inside `appendBatch`; and listing bypasses the coordinator. Read models use `inspect` rather than `load`, so observing a persisted open turn does not commit interruption closers; the [Session preparation decision](2026-08-05-session-preparation.md) owns reuse, reservation, and publication. New backends implement storage primitives rather than copy the eager write lifecycle.
@@ -10,9 +10,9 @@ Status: implemented

 ## 决策

-将一个后端无关的 `PersistenceCoordinator` 提取到 `dsh-session-persistence` 中。协调器统一拥有编排逻辑；每个第一方后端组合一个协调器实例（`new PersistenceCoordinator(ctx, this)`），实现一个小型 `PersistenceBackend` 钩子接口，并将其有状态的公开方法（`create`/`append`/`load`/`inspect`）委托给协调器。由后端拥有的元数据与修订版本列举会绕过协调器。
+将一个后端无关的 `PersistenceCoordinator` 提取到 `dsh-session-persistence` 中。协调器统一拥有编排逻辑；每个第一方后端组合一个协调器实例（`new PersistenceCoordinator(ctx, this)`），实现一个小型 `PersistenceBackend` 钩子接口，并将其有状态的公开方法（`create`/`append`/`prepare`/`load`/`inspect`/`readFrom`）委托给协调器。由后端拥有的元数据与修订版本列举会绕过协调器。

-组合，而非继承。协调器是后端持有的具体类，不是后端继承的基类。本 Agent Note 的风险——「协调器不得让非常规后端与继承层级作斗争」——由此规避：后端只暴露钩子，无法触及协调器的私有编排状态。第三方后端仍然可以完全不使用协调器、直接实现抽象服务，包括供读模型使用、不修改状态的 `inspect` 契约。
+组合，而非继承。协调器是后端持有的具体类，不是后端继承的基类。本 Agent Note 的风险——「协调器不得让非常规后端与继承层级作斗争」——由此规避：后端只暴露钩子，无法触及协调器的私有编排状态。第三方后端仍然可以完全不使用协调器、直接实现抽象服务，包括不可变逻辑检查，以及通过 `load` 实现的默认准备回退。

 协调器为每个存活的 `Session` 实例持有一个控制器；该控制器统合初始化、待处理事件与共享 flush promise。每个 `session/event` 都会立即启动排空，而 `session/flush` 只观察完全停稳，不会发起常规写入路径。[flush 控制器简化](../simplification/2026-07-23-collapse-persistence-flush-state.md)定义该生命周期。

@@ -23,9 +23,9 @@ Status: implemented
 五个必需成员加一个可选的生命周期钩子，构成协调器与存储之间唯一的边界：

 - `name`——后端标签，用于 dispose 失败时的 `AggregateError`。
- `loadStored(id)`——按 id 跨所有存储范围读取一个已存储前缀（JSONL 的所有项目目录；SQLite 的 id 全局唯一）。恢复/加载、不修改状态的检查、存活会话接管与创建碰撞探测共用此查找。协调器会断言返回的 id，并在修复或发布状态之前拒绝已存储记录与存活会话的 cwd 不匹配。
+- `loadStored(id)`——按 id 跨所有存储范围读取一个已存储前缀（JSONL 的所有项目目录；SQLite 的 id 全局唯一）。准备、逻辑加载/检查、物理后缀读取、存活会话接管与创建碰撞探测共用此查找。协调器会断言返回的 id，并在修复或发布状态之前拒绝已存储记录与存活会话的 cwd 不匹配。
 - `appendBatch(meta, events, isMaterialized)`——持久追加一个连续批次，在尚未物化时原子地惰性物化会话（物化写入与首批事件必须一起提交——二者之间发生崩溃时，不得留下一个已物化但为空的会话；这就是为什么没有单独的 `materialize` 钩子）。
- `commitRepair(meta, tornMarker, closers)`——使崩溃修复持久化：截断损坏的尾部（当且仅当 `tornMarker !== undefined`）并追加 `closers`。**不要求原子性**——JSONL 合理地分两步 fsync（先截断再追加），SQLite 在一个事务中完成 DELETE+INSERT。用于 `load`（截断 + 合成 closers）和 live-adoption（仅截断，`closers = []`）。
+- `commitRepair(meta, tornMarker, closers)`——使崩溃修复持久化：截断损坏的尾部（当且仅当 `tornMarker !== undefined`）并追加 `closers`。**不要求原子性**——JSONL 合理地分两步 fsync（先截断再追加），SQLite 在一个事务中完成 DELETE+INSERT。用于 `prepare`/`load`（截断 + 合成 closers）和 live-adoption（仅截断，`closers = []`）。
 - `list()`——列出所有已存储的元数据。
 - `close?()`——可选的生命周期清理（SQLite 关闭 db 句柄；JSONL 省略），在 dispose effect 中于排空至完全停稳之后被 await，因此 close 失败不会掩盖排空错误。

@@ -35,7 +35,7 @@ Status: implemented

 ## 测试

-共享的 `runPersistenceContract`（公开 API 契约）为每个后端运行，并证明在 `load` 执行恢复之前，`inspect` 会保持被中断的日志与修订版本不变。`runCoordinatorContract`（`tests/coordinator-contract.ts`）通过内存参考实现、JSONL 与 SQLite 覆盖接管、HMR、碰撞、会话与后端 dispose 排空，以及崩溃尾部修复。协调器专属测试覆盖立即执行的后续批次、存活控制器清理、同 id 链尾竞态、排空失败重试与关闭顺序。各后端自身的测试规格只保留存储机制。每个真实后端都有一个经由协调器的崩溃尾部修复测试，以覆盖不透明 marker 分支，因为契约中的崩溃用例会产生合成 closers，却不会产生 torn marker。
+共享的 `runPersistenceContract`（公开 API 契约）为每个后端运行，并证明 `inspect` 会配平被中断的逻辑视图但不改变存储或修订版本，随后由 `prepare` 或 `load` 提交恢复。`runCoordinatorContract`（`tests/coordinator-contract.ts`）通过内存参考实现、JSONL 与 SQLite 覆盖接管、HMR、碰撞、会话与后端 dispose 排空和崩溃尾部修复。`persistence.spec.ts` 与 `preparations.spec.ts` 覆盖准备复用与预留、有界准备状态淘汰、立即执行的后续批次、存活控制器清理、同 id 链尾竞态、排空失败重试与关闭顺序。各后端自身的测试规格只保留存储机制。每个真实后端都有一个经由协调器的崩溃尾部修复测试，以覆盖不透明 marker 分支，因为契约中的崩溃用例会产生合成 closers，却不会产生 torn marker。

 ## 曾考虑的替代方案

@@ -44,4 +44,4 @@ Status: implemented

 ## 后果

-协调器增加了一层间接、一个不透明的 torn marker 和脱离会话生命周期的退役任务，但将此前每个后端重复的、对正确性要求很高的编排逻辑集中到一处。会话 dispose 仍是仅观察事件，因此会话所有者不会等待持久化退役；协调器会收容失败、在存活控制器中保留待处理事件，并以后端 teardown 为完全停稳边界。其钩子面保持窄小：标识校验、接管、碰撞检查与不修改状态的检查共用 `loadStored`；物化保持在 `appendBatch` 内原子完成；列举绕过协调器。读模型使用 `inspect` 而非 `load`，因此观察已持久化但仍开放的轮次时，不会因提交中断 closers 而与新的存活所有者产生竞态。新后端只需实现存储原语，而无需复制立即写入生命周期。
+协调器增加了一层间接、一个不透明的 torn marker、脱离会话生命周期的退役任务，以及有界的已准备 Session 状态，但将此前每个后端重复的、对正确性要求很高的编排逻辑集中到一处。会话 dispose 仍是仅观察事件，因此会话所有者不会等待持久化退役；协调器会收容失败、在存活控制器中保留待处理事件，并以后端 teardown 为完全停稳边界。其钩子面保持窄小：标识校验、接管、碰撞检查、准备与不可变检查共用 `loadStored`；物化保持在 `appendBatch` 内原子完成；列举绕过协调器。读模型使用 `inspect` 而非 `load`，因此观察已持久化但仍开放的轮次时不会提交中断 closers；复用、预留与发布由 [Session 准备阶段决策](2026-08-05-session-preparation.md)定义。新后端只需实现存储原语，而无需复制立即写入生命周期。
@@ -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/architecture/2026-07-19-gui-web-client-architecture.md
-2026-07-19-gui-web-client-architecture.md: b306f3b155d9d9208066c3f25ad2c4fb4683b1ee
-2026-07-19-gui-web-client-architecture.zh.md: 28632667c45b360eb2bc5f0d06f10b9df910770d
+2026-07-19-gui-web-client-architecture.md: 1a91d88818c374a1637b546fb3ddf6647af68570
+2026-07-19-gui-web-client-architecture.zh.md: 5c0bacde9836d45812895f5d9c89a0e8974ed7a1
@@ -44,7 +44,7 @@ Implementation homes: registry core and the props-share types in `packages/clien

 A service is a plugin's only API surface toward other plugins (UI components and injection faces are not APIs; a plugin nobody calls mounts no service — ui-trajectory is the minimal-plugin exemplar: no ctx service, only view-slot registrations). The roster: `ctx.connection` (api client + stream handles), `ctx.slots` (registry wrapper emitting `slots/changed`, render entry, renderer install seam), `ctx.sessions` (list store, current-session state, scope tree), `ctx.loader`, `ctx.theme`, `ctx.i18n`, `ctx.layout` (cross-plugin view navigation), `ctx.conversation` (send/cancel/startSession). Viewing state that used to live in service stores (panel widths, selection, drafts) now lives in entry-declared stores per the [slot system standard](2026-07-22-slot-type-chain-implementation.md).

-There is no registration model besides slots — the former view and tool rings both dissolved into it. Conversation views are entries of the `'conversation.view'` list slot ui-conversation declares, tab metadata rides the registration options (`id`/`order`/`label`), and per-view chrome lives inside the view components themselves. A tool row is a keyed child slot each view declares for itself — today `'conversation.chat.toolview'` (keyed/session), declared by the chat entry's `children` table; the key space is runtime-open (SlotMap declares slots, never keys), which is what the tool ring's open tool-name set required. The render site dispatches per row via `entryKey: toolName` with `GenericToolCard` as the call-site `fallback`; the owner payload is the uniform `ToolRowOwnerProps` (`callId`/`toolName`/`block`/`openDetails`), and `ToolRowProps` composes it with the session standard kit for registrant components. Registrants are plain plugins with zero dedicated machinery: `ctx.slots.register({ name: 'conversation.chat.toolview', key: '<tool>', inject? }, Row)`, with `inject: ['slots', 'conversation']` as the load-order seam (the conversation service being present guarantees the slot is declared). Interaction drafts and other row state ride the ordinary store seat. Trajectory/waterfall get same-shaped slots (names fixed by the slot-naming discipline `<domain>.<entry>.<hole>`, one shared owner type) that land with their own row render sites — RendersCheck rejects a declaration nobody renders, so the two slots cannot be declared early.
+There is no registration model besides slots — the former view and tool rings both dissolved into it. Conversation views are entries of the `'conversation.view'` list slot ui-conversation declares, tab metadata rides the registration options (`id`/`order`/`label`), and per-view chrome lives inside the view components themselves. A tool row is a keyed child slot each view declares for itself — today `'conversation.chat.toolview'` (keyed/session), declared by the chat entry's `children` table; the key space is runtime-open (SlotMap declares slots, never keys), which is what the tool ring's open tool-name set required. The render site dispatches per row via `entryKey: toolName` with `GenericToolCard` as the call-site `fallback`; the owner payload is the uniform `ToolRowOwnerProps` (`callId`/`toolName`/`block`/`openDetails`), and `ToolRowProps` composes it with the session standard kit for registrant components. Registrants are plain plugins with zero dedicated machinery: `ctx.slots.inject('conversation.chat.toolview', () => ctx.slots.register({ name: 'conversation.chat.toolview', key: '<tool>', inject? }, Row))`; the declaration is the load and reload dependency, independently from `ConversationService` ([decision](2026-08-05-slot-declaration-injection.md)). Interaction drafts and other row state ride the ordinary store seat. Trajectory/waterfall get same-shaped slots (names fixed by the slot-naming discipline `<domain>.<entry>.<hole>`, one shared owner type) that land with their own row render sites — RendersCheck rejects a declaration nobody renders, so the two slots cannot be declared early.

 **Scope addressing** mirrors the host's agent-scope idiom: services are root singletons whose methods take no sessionId — they read the caller's scope mark (`scopeOf(ctx)`). Inside a session scope, `ctx.conversation.send('hi', 'queue')` targets that session; cross-session calls re-target by switching ctx (`ctx.sessions.scope(id)!.conversation.send(...)`); calling a scoped method from root ctx throws. Client session scopes are minted like host agent scopes (a no-op plugin fiber + a scope-key extend), built lazily on first viewing and torn down only when the session is removed and unwatched — host-session death alone does not tear a scope (it freezes into a read-only viewport).

@@ -44,7 +44,7 @@ slot 体系有自己的 RFC——[slot 体系标准](2026-07-22-slot-type-chain-

 服务是插件对其他插件的唯一 API 面（UI 组件与注入面都不是 API；无人调用的插件不挂服务——ui-trajectory 即最小插件样板：无 ctx 服务，只做视图坑注册）。名册：`ctx.connection`（api client + 流句柄）、`ctx.slots`（注册表包装层，发 `slots/changed`，渲染入口，渲染器安装缝）、`ctx.sessions`（列表 store、当前会话状态、scope 树）、`ctx.loader`、`ctx.theme`、`ctx.i18n`、`ctx.layout`（跨插件视图导航）、`ctx.conversation`（send/cancel/startSession）。过去住在服务 store 里的观看态（面板宽、选中、草稿）现按 [slot 体系标准](2026-07-22-slot-type-chain-implementation.md) 住 entry 声明的 store。

-slot 之外不存在第二种注册模型——原视图环与工具环都已溶解进来。会话视图即 ui-conversation 声明的 `'conversation.view'` list 坑的 entry，tab 元数据随注册 options（`id`/`order`/`label`）走，per-view chrome 住视图组件自身。工具行是各视图自己声明的 keyed 子槽——今天是 `'conversation.chat.toolview'`（keyed/session），由 chat 条目的 `children` 表声明；key 空间运行时开放（SlotMap 声明槽、从不声明 key），这正是工具环「tool 名开放集」的原需求。渲染点逐行以 `entryKey: toolName` 分发、以 `GenericToolCard` 作调用点 `fallback`；owner 载荷是统一的 `ToolRowOwnerProps`（`callId`/`toolName`/`block`/`openDetails`），`ToolRowProps` 把它与 session 标配 kit 预组合供注册方组件取用。注册方就是普通插件、零专用设施：`ctx.slots.register({ name: 'conversation.chat.toolview', key: '<tool>', inject? }, Row)`，以 `inject: ['slots', 'conversation']` 作加载序缝（conversation 服务在场即保证槽已声明）。交互草稿等行内状态走普通 store 席位。trajectory/waterfall 得同形槽（槽名按槽名纪律 `<域>.<条目>.<孔位>` 已定死，共用一张 owner 类型），随各自的行渲染点落地——RendersCheck 拒绝无人渲染的声明，两槽无法提前声明。
+slot 之外不存在第二种注册模型——原视图环与工具环都已溶解进来。会话视图即 ui-conversation 声明的 `'conversation.view'` list 坑的 entry，tab 元数据随注册 options（`id`/`order`/`label`）走，per-view chrome 住视图组件自身。工具行是各视图自己声明的 keyed 子槽——今天是 `'conversation.chat.toolview'`（keyed/session），由 chat 条目的 `children` 表声明；key 空间运行时开放（SlotMap 声明槽、从不声明 key），这正是工具环「tool 名开放集」的原需求。渲染点逐行以 `entryKey: toolName` 分发、以 `GenericToolCard` 作调用点 `fallback`；owner 载荷是统一的 `ToolRowOwnerProps`（`callId`/`toolName`/`block`/`openDetails`），`ToolRowProps` 把它与 session 标配 kit 预组合供注册方组件取用。注册方就是普通插件、零专用设施：`ctx.slots.inject('conversation.chat.toolview', () => ctx.slots.register({ name: 'conversation.chat.toolview', key: '<tool>', inject? }, Row))`；声明本身就是加载与重载依赖，不依赖 `ConversationService`（[决策](2026-08-05-slot-declaration-injection.md)）。交互草稿等行内状态走普通 store 席位。trajectory/waterfall 得同形槽（槽名按槽名纪律 `<域>.<条目>.<孔位>` 已定死，共用一张 owner 类型），随各自的行渲染点落地——RendersCheck 拒绝无人渲染的声明，两槽无法提前声明。

 **scope 寻址**与 host 侧 agent scope 惯例同构：服务是 root 单例，方法不收 sessionId——它们读调用方 ctx 上的 scope 标（`scopeOf(ctx)`）。在会话 scope 内，`ctx.conversation.send('hi', 'queue')` 自动打到该会话；跨会话调用换 ctx 定向（`ctx.sessions.scope(id)!.conversation.send(...)`）；从 root ctx 直接调 scoped 方法即 throw。client 会话 scope 的铸造方式与 host agent scope 相同（no-op 插件 fiber + scope 键 extend），首次观看时惰性建，只有会话被移除且无人观看才拆——仅 host 会话死亡不拆 scope（冻结为只读视窗）。

@@ -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/architecture/2026-07-19-zstandard-jsonl-session-logs.md
-2026-07-19-zstandard-jsonl-session-logs.md: 287ec94a91101850e9343d36ffd27870daf1333b
-2026-07-19-zstandard-jsonl-session-logs.zh.md: 4e578432640651de1eb1977229b7cdd462766c24
+2026-07-19-zstandard-jsonl-session-logs.md: 93fc20f931c75552352834b9340e7d38680d4254
+2026-07-19-zstandard-jsonl-session-logs.zh.md: 061d7fcb55c775eed10e99bae47777d32cc8eee1
@@ -28,7 +28,7 @@ First materialization compresses the two initial frames before opening the tempo

 ### Read, listing, and crash recovery

-A frame-boundary scanner reads the standard magic, variable header fields, block headers and payload sizes, and optional checksum trailer. It does not interpret compressed blocks. Complete frames are decompressed independently and sequentially with Node's default `ZSTD_e_end`, which requires frame completion and validates their checksums, and their plaintext is passed to the existing JSONL scanner. A checksum/decompression failure in any complete frame, a malformed complete-frame JSONL tail, or invalid frame structure is corruption and rejects.
+A frame-boundary scanner reads the standard magic, variable header fields, block headers and payload sizes, and optional checksum trailer. It does not interpret compressed blocks. Complete frames are independently checksum-validated and passed through the [large-session restore pipeline](2026-08-05-large-session-jsonl-restore-pipeline.md), which owns decoder reuse, cooperative yielding, and incremental JSONL scanning. A checksum/decompression failure in any complete frame, a malformed complete-frame JSONL tail, or invalid frame structure is corruption and rejects.

 Listing reads in bounded chunks only until the first complete frame is available, validates and decompresses that header frame, and never reads an event frame. The dedicated header frame therefore preserves metadata-only listing even for very large session logs.

@@ -53,5 +53,5 @@ The shared persistence and coordinator contracts run against both encodings. Bac
 - Ordinary session roots store `.jsonl.zstd` and retain append-only, fsync, rollback, and interrupted-turn recovery semantics.
 - Raw JSONL remains a deliberate configuration, but changing encoding requires a fresh/separate root or selecting the mode that matches existing artifacts.
 - One frame per durable batch adds bounded framing/checksum overhead and allows header-only listing plus repair from an exact append boundary.
- External tools must understand concatenated Zstandard frames or consume raw-mode artifacts; generic one-shot Node decompression reads only the first independent frame, so backend reads walk frames explicitly.
+- External tools must understand concatenated Zstandard frames or consume raw-mode artifacts; generic one-shot Node decompression reads only the first independent frame, so backend reads walk frames through the [restore pipeline](2026-08-05-large-session-jsonl-restore-pipeline.md).
 - The implementation depends on Node's experimental built-in Zstandard API without an npm dependency; the supported-version compatibility gate makes drift visible.
@@ -28,7 +28,7 @@ JSONL 持久化后端会逐字保留每个 `SessionEvent`，其中包括数量

 ### 读取、列举与崩溃恢复

-帧边界扫描器会读取标准魔数、可变头字段、块头与负载长度，以及可选校验和尾部，但不会解释压缩块。后端使用 Node 默认的 `ZSTD_e_end` 独立且按顺序解压完整帧；该模式要求帧完整并验证各帧校验和，再把明文交给既有 JSONL 扫描器。任何完整帧的校验和或解压失败、完整帧中畸形的 JSONL 尾部，或者无效帧结构都属于损坏并拒绝加载。
+帧边界扫描器会读取标准魔数、可变头字段、块头与负载长度，以及可选校验和尾部，但不会解释压缩块。完整帧会独立验证校验和，再进入[大型会话恢复流水线](2026-08-05-large-session-jsonl-restore-pipeline.md)；该流水线负责复用解码器、协作式让出事件循环和增量扫描 JSONL。任何完整帧的校验和或解压失败、完整帧中畸形的 JSONL 尾部，或者无效帧结构都属于损坏并拒绝加载。

 列举只按有界分片读取到第一个完整帧可用为止，验证并解压该头部帧，绝不读取事件帧。因此，即使会话日志很大，专用头部帧仍能维持仅元数据列举。

@@ -53,5 +53,5 @@ CLI、ACP 与 stdio 应用包公开对称的 `persistenceCompression` 透传配
 - 普通会话根目录存储 `.jsonl.zstd`，并保留仅追加、fsync、回滚与中断轮次恢复语义。
 - 原始 JSONL 仍是显式配置，但切换编码需要使用全新或单独根目录，或者选择与既有产物匹配的模式。
 - 每个持久批次一个帧会增加有界的帧与校验和开销，同时支持仅头部列举和从精确追加边界开始修复。
- 外部工具必须理解串联的 Zstandard 帧，或者消费原始模式产物；Node 通用的一次性解压只读取第一个独立帧，因此后端读取会显式遍历各帧。
+- 外部工具必须理解串联的 Zstandard 帧，或者消费原始模式产物；Node 通用的一次性解压只读取第一个独立帧，因此后端读取会通过[恢复流水线](2026-08-05-large-session-jsonl-restore-pipeline.md)遍历各帧。
 - 实现依赖 Node 的实验性内置 Zstandard API，但不增加 NPM 依赖；受支持版本兼容性门禁会暴露 API 漂移。
@@ -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/architecture/2026-07-22-slot-type-chain-implementation.md
-2026-07-22-slot-type-chain-implementation.md: e88361701fc05c1ab30174dde147ae9558265ce6
-2026-07-22-slot-type-chain-implementation.zh.md: 8ca6781e42764fc8d7f7de0f9f25ca6c110d4be0
+2026-07-22-slot-type-chain-implementation.md: 2f0ec32766100e492c68c474f8798be3df0a3d15
+2026-07-22-slot-type-chain-implementation.zh.md: 75e89d3f57b96a1699981123e8361c775db2b8a7
@@ -36,6 +36,8 @@ There is no separate slot-definition API. The `children` object both **declares

 Parity rule: **the declaring entry holds the exclusive right to render its child slots**, settled entirely at register time (misconfiguration fails loud at load; the render hot path carries no checks). Loud-at-load cases: a second entry declaring an already-declared slot; registering into an undeclared slot; one store handle mounted under two scopes; a chain registration missing its `select`.

+A contributor whose activation order is independent from the declaring entry uses `ctx.slots.inject(key, callback)` and keeps direct `register()` fail-loud. The declaration, contributor, replacement, and failure lifetimes are specified by the [slot declaration injection decision](2026-08-05-slot-declaration-injection.md).
+
 `SlotMap` declaration merging remains the type authority, and an entry declares only its own axes plus the **owner share** — the registrant's injected props never enter the global table ("whoever injects it, owns its type").

 ### Component props: four shares, each from its own source of truth
@@ -36,6 +36,8 @@ ctx.slots.register({

 对等原则：**声明子 slot 的 entry 独占渲染这些子 slot 的权力**，全部在 register 时确定（配置错误会在装载时明确失败；渲染热路径不再校验）。装载即炸的情形：第二个 entry 声明已被声明的 slot；向未声明的 slot register；同一个 store 句柄挂到两个 scope 之下；chain 注册缺 `select`。

+激活顺序独立于声明条目的贡献方使用 `ctx.slots.inject(key, callback)`，并让直接调用 `register()` 继续大声失败。声明、贡献方、替换与失败各自的生命周期由 [slot 声明注入决策](2026-08-05-slot-declaration-injection.md) 规定。
+
 `SlotMap` 声明合并仍是类型权威，且 entry 只声明自己的轴加 **owner 份额**——注册方注入的 props 永不进入全局表（「谁注入的，类型归谁」）。

 ### 组件 props：四份额，各有唯一真源
@@ -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/architecture/2026-07-23-toolview-dissolution.md
-2026-07-23-toolview-dissolution.md: 406e5c181aabb635f9d6dcb12d8a9b8b6697368e
-2026-07-23-toolview-dissolution.zh.md: f42881c5f2e4c661d7fa40bfca7d0b53c1beef5e
+2026-07-23-toolview-dissolution.md: 97d8beb4de43d9bc6348d942e5460d0321592b32
+2026-07-23-toolview-dissolution.zh.md: db93c6252d5d42d1fd85ce81ad430d95f4324cf2
@@ -14,7 +14,7 @@ After the view ring dissolved into the slot system, the client kept exactly one

 The tool ring is gone as independent infrastructure: a tool row is a **keyed child slot each view declares for itself**, and the client has exactly one registration model. The justification above was hollow — a keyed slot's *key space* is already runtime-open (SlotMap declares slots, never keys; the ask-user composer's `key: 'question'` was the precedent), so the open tool-name set fits `entryKey` dispatch natively.

-Shipped shape (current-state narrative also in the [architecture note](2026-07-19-gui-web-client-architecture.md)): the chat entry's `children` table declares `'conversation.chat.toolview'` (keyed/session); the render site dispatches per row via `entryKey: toolName` with `GenericToolCard` as the call-site `fallback` (the default card is domain property; the fallback option is ordinary renderSlot grammar). The owner payload is the uniform `ToolRowOwnerProps` (`callId`/`toolName`/`block`/`openDetails` — details being a session-level facility, not chat-private), and `ToolRowProps` pre-composes it with the session standard kit for registrant components. A registrant is a plain plugin: `ctx.slots.register({ name: 'conversation.chat.toolview', key: '<tool>', inject? }, Row)` with `inject: ['slots', 'conversation']` as the load-order seam — apply mounts `ConversationService` *after* the chat registration, so the service being present guarantees the slot is declared, by construction. The bash sample is the third-party-posture exemplar and paints the same ToolRow chrome as Think (`Bash · {description}`). Trajectory/waterfall toolview slots share this exact shape (names fixed by the slot-naming discipline `<domain>.<entry>.<hole>`, one shared owner type) and land with their own row render sites — RendersCheck rejects a declaration nobody renders, so the type system, not convention, blocks early empty declarations.
+Shipped shape (current-state narrative also in the [architecture note](2026-07-19-gui-web-client-architecture.md)): the chat entry's `children` table declares `'conversation.chat.toolview'` (keyed/session); the render site dispatches per row via `entryKey: toolName` with `GenericToolCard` as the call-site `fallback` (the default card is domain property; the fallback option is ordinary renderSlot grammar). The owner payload is the uniform `ToolRowOwnerProps` (`callId`/`toolName`/`block`/`openDetails` — details being a session-level facility, not chat-private), and `ToolRowProps` pre-composes it with the session standard kit for registrant components. A registrant is a plain plugin using `ctx.slots.inject('conversation.chat.toolview', () => ctx.slots.register({ name: 'conversation.chat.toolview', key: '<tool>', inject? }, Row))`; the declaration itself governs activation and replacement, without a false `ConversationService` edge ([decision](2026-08-05-slot-declaration-injection.md)). The bash sample is the third-party-posture exemplar and paints the same ToolRow chrome as Think (`Bash · {description}`). Trajectory/waterfall toolview slots share this exact shape (names fixed by the slot-naming discipline `<domain>.<entry>.<hole>`, one shared owner type) and land with their own row render sites — RendersCheck rejects a declaration nobody renders, so the type system, not convention, blocks early empty declarations.

 Registry-era responsibilities all have successor homes: inject caching and row error isolation ride the framework renderer (entry×scope cache, per-entry `SlotErrorBoundary`); subscribe/getVersion ride the slot core's per-key version machinery; the future "store seat" is the ordinary store seat keyed slots already have (interaction-draft durability is its first named consumer); miss fallback is the call-site `fallback` option.

@@ -34,4 +34,4 @@ Four behavioral deltas were accepted deliberately, not overlooked. Cross-view ap

 ## Consequences

-The client has one registration model; auditing who renders tool rows = reading register calls, the same audit as every other slot. Registrants get the framework's error isolation, inject caching, and store seat for free — no capability ships twice. The costs are the accepted semantic changes above (chiefly: per-view registration for cross-view rows, and no third-party registry-level override), plus one subtlety the load-order seam carries: registrant plugins must declare `inject: ['conversation']` to sequence after the slot declaration, a convention the seam makes correct by construction but does not statically force on third parties.
+The client has one registration model; auditing who renders tool rows = reading register calls, the same audit as every other slot. Registrants get the framework's error isolation, inject caching, and store seat for free — no capability ships twice. The costs are the accepted semantic changes above (chiefly: per-view registration for cross-view rows, and no third-party registry-level override). Independent registrants name the typed slot in `ctx.slots.inject`, so the dependency is explicit and follows declaration replacement without a service-order convention.
@@ -14,7 +14,7 @@ Status: implemented

 工具环作为独立基础设施已消失：工具行是**各视图为自己声明的 keyed 子槽**，client 全域只剩一种注册模型。上述理由是空的——keyed slot 的 *key 空间*本就运行时开放（SlotMap 声明槽、从不声明 key；ask-user composer 的 `key: 'question'` 即先例），开放的 tool 名集合天然适配 `entryKey` 分发。

-落地形态（现状叙述同见[架构注](2026-07-19-gui-web-client-architecture.md)）：chat 条目的 `children` 表声明 `'conversation.chat.toolview'`（keyed/session）；渲染点逐行以 `entryKey: toolName` 分发、以 `GenericToolCard` 作调用点 `fallback`（默认卡片是域产权；fallback 选项就是普通 renderSlot 文法）。owner 载荷是统一的 `ToolRowOwnerProps`（`callId`/`toolName`/`block`/`openDetails`——details 是会话级设施，非 chat 私货），`ToolRowProps` 把它与 session 标配 kit 预组合供注册方组件取用。注册方就是普通插件：`ctx.slots.register({ name: 'conversation.chat.toolview', key: '<tool>', inject? }, Row)`，以 `inject: ['slots', 'conversation']` 作加载序缝——apply 把 `ConversationService` 挂在 chat 注册*之后*，故服务在场即保证槽已声明，构造使然。bash 样例即第三方姿态的样板，并与 Think 绘制同一套 ToolRow chrome（`Bash · {description}`）。trajectory/waterfall 的 toolview 槽共用这套形状（槽名按槽名纪律 `<domain>.<entry>.<hole>` 定死，共用一张 owner 类型），随各自的行渲染点落地——RendersCheck 拒绝无人渲染的声明，挡住提前空声明的是类型系统而非约定。
+落地形态（现状叙述同见[架构注](2026-07-19-gui-web-client-architecture.md)）：chat 条目的 `children` 表声明 `'conversation.chat.toolview'`（keyed/session）；渲染点逐行以 `entryKey: toolName` 分发、以 `GenericToolCard` 作调用点 `fallback`（默认卡片是域产权；fallback 选项就是普通 renderSlot 文法）。owner 载荷是统一的 `ToolRowOwnerProps`（`callId`/`toolName`/`block`/`openDetails`——details 是会话级设施，非 chat 私货），`ToolRowProps` 把它与 session 标配 kit 预组合供注册方组件取用。注册方是使用 `ctx.slots.inject('conversation.chat.toolview', () => ctx.slots.register({ name: 'conversation.chat.toolview', key: '<tool>', inject? }, Row))` 的普通插件；声明本身控制激活与替换，不再引入虚假的 `ConversationService` 依赖（[决策](2026-08-05-slot-declaration-injection.md)）。bash 样例即第三方姿态的样板，并与 Think 绘制同一套 ToolRow chrome（`Bash · {description}`）。trajectory/waterfall 的 toolview 槽共用这套形状（槽名按槽名纪律 `<域>.<条目>.<孔位>` 定死，共用一张 owner 类型），随各自的行渲染点落地——RendersCheck 拒绝无人渲染的声明，挡住提前空声明的是类型系统而非约定。

 registry 时代的职责各有后继居所：inject 缓存与行错误隔离乘框架渲染器（entry×scope 缓存、per-entry `SlotErrorBoundary`）；subscribe/getVersion 乘 slot core 的 per-key 版本机；将来的「store 席位」就是 keyed slot 本就拥有的普通 store 席位（交互草稿耐久性是其首个具名消费者）；miss 兜底即调用点 `fallback` 选项。

@@ -34,4 +34,4 @@ registry 时代的职责各有后继居所：inject 缓存与行错误隔离乘

 ## Consequences

-client 只有一种注册模型；审计谁渲染工具行 = 读 register 调用，与其他所有 slot 同一套审计。注册方免费获得框架的错误隔离、inject 缓存与 store 席位——没有能力要建两遍。代价即上文接受的语义变化（主要是：跨视图行要逐视图注册、第三方无 registry 级覆盖），外加加载序缝携带的一处微妙：注册方插件须声明 `inject: ['conversation']` 才排在槽声明之后，这条约定由序缝构造保证正确、但不对第三方静态强制。
+client 只有一种注册模型；审计谁渲染工具行 = 读 register 调用，与其他所有 slot 同一套审计。注册方免费获得框架的错误隔离、inject 缓存与 store 席位——没有能力要建两遍。代价即上文接受的语义变化（主要是：跨视图行要逐视图注册、第三方无 registry 级覆盖）。独立注册方在 `ctx.slots.inject` 中点名有类型约束的 slot，因此依赖关系既显式，又能跟随声明替换，无需服务顺序约定。
@@ -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/architecture/2026-08-05-large-session-jsonl-restore-pipeline.md
+2026-08-05-large-session-jsonl-restore-pipeline.md: eab53c683880ef7095233ed8122e532eb5add547
+2026-08-05-large-session-jsonl-restore-pipeline.zh.md: 039e0c193179677b57e742d55f4c7df6bdff852f
@@ -0,0 +1,52 @@
+# Agent Note: Large-session JSONL restore pipeline
+
+Status: implemented
+
+English | [中文](2026-08-05-large-session-jsonl-restore-pipeline.zh.md)
+
+## Problem
+
+Restoring a stored session activates it and materializes its complete authoritative event log before the agent can run. Large JSONL artifacts made that one-time operation pay several avoidable costs: each independent Zstandard frame created and closed a decoder context, decoded plaintext was accumulated and rescanned as whole-log buffers and strings, and freshly parsed events went through generic snapshot and deep-freeze paths designed for borrowed or cyclic values.
+
+A representative profile contained 61.8 MiB of Zstandard data, 97.1 MiB of plaintext, and 1,307,073 events. The restore path must reduce its CPU and memory cost without weakening checksum validation, committed-region corruption detection, torn-tail recovery, sequence and surface validation, or the session log's immutability.
+
+## Decision
+
+Restoration is one ownership-transfer pipeline from the persistence artifact into `Session.fromRestore`. The compressed artifact remains the source buffer, while each decoding and scanning stage consumes the previous stage's output incrementally without retaining a whole-log plaintext or parsed copy; the resulting event array is the only complete decoded representation.
+
+### Frame decoding
+
+The structural Zstandard scanner identifies complete frame ranges before decoding. The dedicated first frame is decoded and parsed separately as the session header; subsequent plaintext frames are yielded in order into the JSONL scanner.
+
+`ZstdFrameDecoder` gives the reader one lifecycle for interchangeable synchronous implementations. The preferred implementation probes the supported Node 22, 24, and 26 stream shape, reuses one private native decoder context and scratch buffer across all complete frames, and closes it once. If that private shape is unavailable, the factory selects a public `zstdDecompressSync` implementation with the same iterator and checksum-error contract. A yielded scratch view is consumed before the iterator advances.
+
+After approximately 500 ms of accumulated frame work, the asynchronous reader yields at the next frame boundary and observes cancellation before continuing. A single frame remains an indivisible synchronous operation. Complete frames require end-of-frame and checksum validation; only a structurally incomplete final frame uses the existing prefix decoder for recovery.
+
+### Incremental JSONL scanning
+
+`SessionLogScanner` searches raw buffers with `Buffer.indexOf(0x0A)` and converts only complete records to UTF-8 for `JSON.parse`. It carries an incomplete record across decoder writes and copies only that fragment because the private decoder may reuse its output buffer. It does not build a whole plaintext buffer or string, a line array, or a second parsed-record array.
+
+The scanner stops retaining events at the first unparsable row or sequence gap but continues inspecting later complete records. A later `turn/end` proves that the issue lies in the committed region and rejects the log. The Zstandard reader also rejects any unresolved parse, sequence, or partial-record issue after all complete frames; only a structurally torn final frame may contribute a recoverable suffix. Complete records emitted from that torn frame pass through the same scanner and retain the existing repair offset and recovered-event semantics.
+
+### Restore admission
+
+Persistence transfers freshly materialized JSON values to `Session.fromRestore`. These values are detached, acyclic trees, and packed chunk rows expand into newly allocated events, so the restore-only path validates the fixed event envelope with one `for...in` and `switch`, dispatches current-shape checks by event discriminant, and iteratively freezes the owned graph with an explicit `pending` array and no cycle-tracking set. Surface validation records one transition plan and commits that plan when the exact candidate enters the log instead of planning the same event twice.
+
+Borrowed seeds used by ordinary creation and fork paths still take a JSON snapshot and use the generic cycle-safe deep freeze. The specialization therefore changes only durable restoration; it does not weaken acceptance for caller-owned values.
+
+## Alternatives considered
+
+- **One asynchronous native operation per frame** — rejected because dispatch and callback overhead dominates logs containing many small durable batches. Cooperative synchronous decoding pays that overhead only at periodic yield boundaries.
+- **Process the complete log synchronously without yielding** — rejected because it prevents cancellation and event-loop progress for the full restore duration. Frame-boundary yields retain a bounded observation point without splitting codec operations.
+- **Concatenate all plaintext before scanning** — rejected because it retains the compressed input, complete plaintext, whole-log UTF-8 string, line metadata, and parsed rows at the same time, and it rescans a torn-frame prefix.
+- **Implement a streaming JSON parser** — rejected because JSONL already provides record boundaries; native newline search plus `JSON.parse` removes the large intermediates without owning another parser or changing JSON semantics.
+- **Use a shared `WeakSet` while freezing restored events** — rejected because JSON materialization cannot produce cycles, and the set adds a lookup per object while retaining the complete graph during traversal.
+- **Skip validation or freezing for restored values** — rejected because durable storage is a runtime boundary and `Session.events` promises immutable accepted history. The optimized path specializes those operations around stronger ownership facts instead of removing them.
+
+## Consequences
+
+On the representative profile, incremental scanning reduced JSONL scan time from about 598 ms to 397 ms and peak RSS from about 1,494 MiB to 1,060 MiB. Restore admission reduced `Session.fromRestore` from 604–608 ms to about 263 ms, including an `assertSessionEventEnvelope` reduction from about 77 ms to 13 ms. These measurements characterize the optimization input rather than establish runtime limits.
+
+The fast decoder depends on runtime-probed Node internals, but incompatibility selects the public implementation rather than changing correctness. Cancellation is observed around cooperative frame-boundary yields; the deadline is not a hard wall-clock bound inside one frame. The complete event array remains resident because it is the active session's authoritative log; the pipeline removes duplicate representations rather than paginating that state.
+
+Tests force both decoder implementations, compare their frame order and corruption behavior, exercise cooperative cancellation and torn-tail recovery, and retain the existing session envelope, surface, and immutability contracts.
@@ -0,0 +1,52 @@
+# Agent Note: 大型会话 JSONL 恢复流水线
+
+Status: implemented
+
+[English](2026-08-05-large-session-jsonl-restore-pipeline.md) | 中文
+
+## 问题
+
+恢复已存储会话会激活该会话，并在 agent（智能体）运行前物化完整且权威的事件日志。处理大型 JSONL 产物时，这个一次性操作会产生几项不必要的开销：每个独立 Zstandard 帧都会创建并关闭一个解码上下文；解码后的明文会汇总成整份日志的缓冲区和字符串，再进行重复扫描；刚解析出的事件还会进入面向借用值或循环引用值设计的通用快照与深度冻结路径。
+
+一份代表性性能剖析包含 61.8 MiB Zstandard 数据、97.1 MiB 明文和 1,307,073 个事件。恢复路径必须降低 CPU 与内存开销，同时保持校验和验证、已提交区域损坏检测、撕裂尾部恢复、序列与 `surface` 校验，以及会话日志不可变性。
+
+## 决策
+
+恢复过程是一条从持久化产物进入 `Session.fromRestore` 的所有权转移流水线。压缩产物仍作为源缓冲区驻留，但解码与扫描阶段会增量消费上一阶段的输出，不会保留整份日志的明文或解析副本；最终事件数组是唯一完整的已解码表示。
+
+### 帧解码
+
+Zstandard 结构扫描器会在解码前识别完整帧范围。系统单独解码专用首帧并将其解析为会话头部，后续明文帧则按顺序产出并送入 JSONL 扫描器。
+
+`ZstdFrameDecoder` 为可互换的同步实现提供统一生命周期。首选实现会探测受支持 Node 22、24 与 26 的流结构，在所有完整帧之间复用一个私有原生解码上下文和临时缓冲区，最后只关闭一次。如果私有结构不可用，工厂会选择使用公共 `zstdDecompressSync` 的实现，并保持相同的迭代器和校验和错误契约。迭代器产出的临时视图会在进入下一次迭代前被消费。
+
+累计帧处理时间约达 500 ms 后，异步读取器会在下一帧边界让出事件循环，并在继续前观察取消信号。单个帧仍是不可分割的同步操作。完整帧必须通过帧结束与校验和验证；只有结构上不完整的最终帧才使用既有前缀解码器进行恢复。
+
+### 增量 JSONL 扫描
+
+`SessionLogScanner` 使用 `Buffer.indexOf(0x0A)` 在原始缓冲区中查找换行，只把完整记录转换为 UTF-8 并交给 `JSON.parse`。扫描器会跨解码写入保留不完整记录；由于私有解码器可能复用输出缓冲区，它只复制这个片段。扫描过程不会构造整份明文缓冲区或字符串，也不会构造行数组或第二份解析记录数组。
+
+扫描器在遇到第一条无法解析的记录或序列缺口后停止保留事件，但会继续检查后续完整记录。后续出现 `turn/end`，说明问题位于已提交区域，系统会拒绝该日志。处理完所有完整帧后，如果仍存在未决的解析错误、序列错误或部分记录，Zstandard 读取器同样会拒绝日志；只有结构上撕裂的最终帧才能提供可恢复后缀。该撕裂帧产出的完整记录会经过同一扫描器，并保持既有修复偏移量与恢复事件语义。
+
+### 恢复准入
+
+持久化层把刚物化的 JSON 值转移给 `Session.fromRestore`。这些值是已分离且无环的树，打包的分片行也会展开成新分配的事件。因此，恢复专用路径使用一次 `for...in` 与 `switch` 校验固定事件信封，按事件判别字段执行当前数据形状检查，并通过显式 `pending` 数组迭代冻结所拥有的对象图，不使用循环跟踪集合。`surface` 校验会记录一次转换计划；当同一个候选事件进入日志时，系统直接提交该计划，不再对同一事件规划两次。
+
+普通创建与 fork 路径使用的借用 `seed` 仍会创建 JSON 快照，并使用支持循环检测的通用深度冻结。因此，这项特化仅改变持久恢复，不会放宽调用方所有值的准入要求。
+
+## 考虑过的替代方案
+
+- **每帧执行一次异步原生操作**：不予采纳，因为对于包含大量小型持久化批次的日志，调度与回调开销占据主要部分。协作式同步解码只在周期性让出边界支付这类开销。
+- **同步处理完整日志且不让出事件循环**：不予采纳，因为整个恢复期间都无法响应取消或推进事件循环。帧边界让出机制无需拆分编解码操作，就能保留有界的观察点。
+- **扫描前拼接全部明文**：不予采纳，因为该方案会同时保留压缩输入、完整明文、整份日志的 UTF-8 字符串、行元数据和解析记录，并会重新扫描撕裂帧前缀。
+- **实现流式 JSON 解析器**：不予采纳，因为 JSONL 已提供记录边界；使用原生换行搜索与 `JSON.parse` 就能移除大型中间结构，无需自行维护另一套解析器或改变 JSON 语义。
+- **冻结恢复事件时共享一个 `WeakSet`**：不予采纳，因为 JSON 物化不可能产生循环引用，而该集合会对每个对象增加一次查找，并在遍历期间保留完整对象图。
+- **跳过恢复值的校验或冻结**：不予采纳，因为持久存储属于运行时边界，而 `Session.events` 承诺已接受历史不可变。优化路径利用更强的所有权事实特化这些操作，而不是将其移除。
+
+## 后果
+
+在代表性性能剖析中，增量扫描将 JSONL 扫描时间从约 598 ms 降至 397 ms，峰值 RSS 从约 1,494 MiB 降至 1,060 MiB。恢复准入将 `Session.fromRestore` 从 604–608 ms 降至约 263 ms，其中 `assertSessionEventEnvelope` 从约 77 ms 降至 13 ms。这些数据用于描述优化输入，不构成运行时上限。
+
+快速解码器依赖运行时探测的 Node 内部接口，但接口不兼容时会改用公共实现，不会改变正确性。系统会在协作式帧边界让出点观察取消信号；截止时间并不是单个帧内部严格的挂钟时间上限。完整事件数组仍会驻留内存，因为它是活跃会话的权威日志；该流水线移除的是重复表示，并未对这份状态做分页。
+
+测试会强制执行两种解码器实现，比对帧顺序和损坏处理行为，覆盖协作式取消与撕裂尾部恢复，并保留既有会话信封、`surface` 与不可变性契约。
@@ -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/architecture/2026-08-05-session-preparation.md
+2026-08-05-session-preparation.md: 69d39f552ed3041403a24b5aefb435e4e721b09c
+2026-08-05-session-preparation.zh.md: a0ca27eb63552566c918c299bd5fba976687812c
@@ -0,0 +1,68 @@
+# Agent Note: Reusable Session preparation before publication
+
+Status: implemented
+
+English | [中文](2026-08-05-session-preparation.zh.md)
+
+## Problem
+
+Cold history inspection and Agent resume independently materialized the same persisted session log. For a large compressed log, each operation repeated the full read, decompression, parse, validation, freezing, and Session construction. Pagination could therefore pay the cold-read cost again, while making a history query activate an Agent would couple a read lifecycle to a live Agent with no natural retirement point.
+
+Fresh creation and persisted resume also reached the same publication boundary through different construction flows. This obscured the invariant that setup must finish against one unpublished Session before that exact Session and its Agent become visible together.
+
+## Decision
+
+`SessionPreparation` owns one exact unpublished `Session` until publication or rollback. It is a Session lifecycle object, not an Agent lifecycle or activation object. Fresh creation wraps the result of `SessionStore.prepare()`; persisted resume obtains a preparation from `SessionPersistence.prepare()`.
+
+The Agent loop consumes both forms through one setup-and-publication pipeline: it acquires the preparation, builds the private Agent context around `preparation.session`, awaits optional setup, publishes that exact Session and Agent, and disposes the preparation on every exit. Publication transfers the live lifecycle to the existing Session and Agent stores; `SessionPreparation` itself owns no Agent behavior.
+
+This refines the publication boundary from the [Agent lifecycle and ownership decision](2026-06-18-agent-lifecycle-and-ownership-seams.md) without replacing its ownership model.
+
+## Persisted preparation lifecycle
+
+A coordinator-backed persistence implementation loads one cold source into a prepared Session. The backend transfers fresh, mutually unaliased metadata and events together with the source-qualified revision that identifies those exact values; the Session restore path validates and freezes the graphs in place instead of cloning them. The coordinator computes interrupted-turn closers and constructs the exact unpublished Session once. Its immutable header and balanced logical event log form the `SessionInspection` borrowed by readers, while the revision remains internal to persistence.
+
+`inspect(id, signal?)` does not mutate storage. Synthetic closers exist only in the prepared in-memory view, and a torn physical tail remains untouched. Same-id callers share an in-flight cold read. Once ready, the preparation may remain in a per-coordinator LRU whose capacity defaults to five and is configurable by first-party backends. Before reusing a retained source, the coordinator reads that id's current revision; a mismatch evicts a ready source and repeats the cold materialization. A source already committing or reserved for resume remains exclusively owned, so concurrent inspection borrows that immutable view until publication or release.
+
+`prepare(id, signal?)` exclusively reserves the prepared Session. It confirms the retained revision before committing any torn-tail and interrupted-turn repair, establishes the durable cursor, then returns a disposable preparation. A stale source is discarded and reloaded instead of being repaired or published. A successful repair also discards the pre-repair source and materializes the committed log again before reservation, so a newer revision is never associated with an older event graph. Another same-id preparation waits until the reservation is published or released. Publication accepts only the exact reserved Session and attaches the committed cursor without rebuilding its history. Failed setup or cancellation returns an unchanged unpublished Session to the LRU; mutation or attachment consumes the reservation.
+
+The legacy `load(id)` API uses the same preparation and repair machinery, then discards its reservation and returns the immutable logical view. It remains a compatibility API, not the history-to-resume reuse path. This lifecycle extends the [shared persistence coordinator](2026-06-18-shared-persistence-write-coordinator.md) while preserving the storage and recovery rules owned by the [session persistence decision](2026-06-14-session-persistence.md).
+
+## History and resume reuse
+
+History reads use `inspect()`, so repeated pages borrow the same immutable prepared state without activating an Agent. A later resume uses `prepare()` and receives the exact Session retained by inspection; it does not read, decompress, parse, clone, validate, or freeze the complete log again.
+
+If the durable log changes after inspection, its revision changes. The next history read or resume discards a retained ready Session and materializes the new log, so an old event graph cannot be associated with a newer snapshot revision. A source already claimed by an in-flight resume is not evicted: its exclusive owner keeps it through publication or release, and concurrent history may borrow the same immutable view.
+
+Cold continuable-subagent access follows the same path. Descriptor authorization first inspects the child, then `ctx.agents.resume()` reserves and publishes the retained Session. This preserves the lifecycle and authorization rules in the [continuable subagent conversation decision](../feature/2026-07-28-continuable-subagent-conversations.md) while removing its duplicate cold read.
+
+## Boundaries
+
+- `readFrom()` remains a detached physical-suffix API. It neither creates nor consumes a preparation, synthesizes logical closers, or joins the LRU.
+- HMR adoption keeps the live Session authoritative and reads the stored prefix directly. It may truncate a torn physical fragment but never closes the live open turn as interrupted.
+- The cache belongs to one persistence coordinator, not a process-global Session map. Live Sessions are owned by the existing stores and never occupy preparation capacity.
+- A fresh create never claims a cold persisted preparation with the same id. Persistence collisions continue to reject.
+- Third-party persistence implementations retain the abstract `prepare()` fallback through `load()`. They receive the same publication interface but gain exact-object reuse only when they override preparation.
+- Revision validation establishes freshness at the reuse and repair-commit points; it does not add cross-process writer exclusion to a backend. Retries converge after the durable log remains unchanged for one read/check round trip, so continuous external writers can delay preparation.
+
+## Verification
+
+The shared persistence contract pins non-mutating balanced cold inspection and later repair. `persistence.spec.ts` and `preparations.spec.ts` pin same-id in-flight sharing, exact Session reuse across inspect and prepare, revision-triggered refresh before history and resume, single repair commit, exclusive reservation, release after failed setup, ready-entry LRU eviction, append rejection during reservation, and publication of only the reserved Session. Backend tests pin that full and lightweight reads use the same revision identity. Agent-loop and continuable-subagent tests pin the common publication pipeline and inspection-to-resume path across cancellation and teardown.
+
+## Alternatives considered
+
+**Activate an Agent for history reads.** Rejected because pagination would keep query-only Agents live and transfer cache retirement into the Agent lifecycle.
+
+**Cache only `{ meta, events }`.** Rejected because resume would still reconstruct, validate, freeze, and copy a Session from the cached values. The exact unpublished Session is the reusable unit.
+
+**Keep a process-global Session map.** Rejected because it would cross backend and runtime ownership boundaries, retain unbounded identities, and duplicate the live Session store.
+
+**Add a restore transaction or coordinator to the Agent loop.** Rejected because cold reading, repair, reservation, and cursor attachment are persistence and Session concerns. The Agent loop only needs the uniform `SessionPreparation` ownership boundary.
+
+**Turn `readFrom()` into logical preparation.** Rejected because watermark consumers need a detached physical suffix and, on seek-capable backends, a bounded read. Recovery balancing and whole-Session reuse have different semantics.
+
+## Consequences
+
+One cold materialization can serve history pagination, subagent descriptor inspection, and a later resume. Ownership transfer removes redundant restoration clones, while the bounded per-coordinator LRU limits memory and avoids creating live Agents for queries. Create and resume share one publication protocol without merging Agent and Session responsibilities.
+
+The first cold inspection now pays the complete validation and Session-construction cost and may retain that unpublished Session until eviction. Persistence must coordinate reservation, append, repair, and publication, and callers must treat inspection values as immutable borrowed state. Backends that rely on the default `prepare()` remain correct but do not receive the reuse optimization.
@@ -0,0 +1,68 @@
+# Agent Note: 发布前可复用的 Session 准备阶段
+
+Status: implemented
+
+[English](2026-08-05-session-preparation.md) | 中文
+
+## 问题
+
+冷历史检查和 agent（智能体）恢复会分别实体化同一份持久会话日志。对于大型压缩日志，每次操作都会重新完整读取、解压、解析、验证、冻结并构造 Session。因此，历史分页可能反复承担冷读成本；如果改为由历史查询激活 agent，读取生命周期又会与缺少自然退出时机的实时 agent 耦合。
+
+新建和持久化恢复也通过不同构造流程抵达相同的发布边界。这使一项关键不变量不够清楚：设置必须基于一个未发布的 Session 完成，之后系统才能同时公开这个精确 Session 及其 agent。
+
+## 决策
+
+`SessionPreparation` 持有一个精确的未发布 `Session`，直至发布或回滚。它属于 Session 生命周期，不属于 agent 生命周期或激活机制。新建流程包装 `SessionStore.prepare()` 的结果；持久化恢复则从 `SessionPersistence.prepare()` 取得准备对象。
+
+agent loop（智能体循环）通过同一条设置与发布流水线消费这两种形式：先取得准备对象，围绕 `preparation.session` 构建私有 agent 上下文，等待可选设置完成，再发布该精确 Session 和 agent，并在所有退出路径上 dispose 准备对象。发布后，实时生命周期由现有 Session 与 agent 存储接管；`SessionPreparation` 本身不负责任何 agent 行为。
+
+该机制细化了 [agent 生命周期与所有权决策](2026-06-18-agent-lifecycle-and-ownership-seams.md)中的发布边界，但不替换其所有权模型。
+
+## 持久化准备生命周期
+
+使用协调器的持久化实现会将一个冷源加载为准备完成的 Session。后端转移新鲜、彼此无别名的元数据和事件，以及标识这些精确值的来源限定 revision；Session 恢复路径直接验证并冻结这些对象图，不再复制。协调器计算中断轮次的 closer，并且只构造一次精确的未发布 Session。其不可变 header 与平衡逻辑事件日志构成读取方借用的 `SessionInspection`，revision 则保留在持久化内部。
+
+`inspect(id, signal?)` 不修改存储。合成 closer 只存在于准备完成的内存视图中，撕裂的物理尾部保持不变。同 id 调用方共享进行中的冷读。准备完成后，该对象可以进入每个协调器自己的 LRU；第一方后端可配置容量，默认保留五个。协调器复用保留源之前会读取该 id 的当前 revision；如果不匹配，就淘汰处于就绪阶段的源并重新完成冷实体化。已经进入提交或为恢复而预留的源仍由其所有者独占，因此并发检查会借用该不可变视图，直至发布或释放。
+
+`prepare(id, signal?)` 独占预留准备完成的 Session。它先确认保留的 revision，再提交撕裂尾部和中断轮次修复、建立持久游标，最后返回可 dispose 的准备对象。陈旧源会被丢弃并重新读取，不会参与修复或发布。修复成功后也会丢弃修复前的源，并在预留前重新实体化已提交日志，以免把较新的 revision 关联到较旧的事件对象图。同 id 的另一个准备请求会等待当前预留发布或释放。发布只接受精确的预留 Session，并直接附接已提交游标，无需重建历史。设置失败或取消时，未发生变化的未发布 Session 会返回 LRU；发生变更或完成附接后，系统会消费该预留。
+
+存量 `load(id)` API 使用相同的准备和修复机制，随后丢弃其预留并返回不可变逻辑视图。它保留为兼容 API，不承担历史到恢复的复用路径。该生命周期扩展了[共享持久化协调器](2026-06-18-shared-persistence-write-coordinator.md)，同时继续遵循[会话持久化决策](2026-06-14-session-persistence.md)所规定的存储与恢复规则。
+
+## 历史与恢复复用
+
+历史读取使用 `inspect()`，因此重复分页可以借用同一份不可变准备状态，而不会激活 agent。后续恢复调用 `prepare()`，直接取得检查阶段保留的精确 Session；系统不会再次完整读取、解压、解析、复制、验证或冻结日志。
+
+如果持久日志在检查后发生变化，其 revision 也会变化。下一次历史读取或恢复会丢弃保留且处于就绪阶段的 Session，并实体化新日志，因此旧事件对象图不会被关联到较新的快照 revision。已经由进行中恢复操作取得的源不会被淘汰：其独占所有者会持有它直至发布或释放，并发历史读取可以借用同一个不可变视图。
+
+冷 continuable subagent 访问沿用同一路径。系统先检查子会话并完成 descriptor 授权，再由 `ctx.agents.resume()` 预留并发布保留的 Session。这样既遵循 [continuable subagent 会话决策](../feature/2026-07-28-continuable-subagent-conversations.md)中的生命周期与授权规则，也消除了重复冷读。
+
+## 边界
+
+- `readFrom()` 仍是脱离的物理后缀 API。它不会创建或消费准备对象，不会合成逻辑 closer，也不会进入 LRU。
+- HMR（热模块替换）接管继续以实时 Session 为权威，并直接读取已存储前缀。它可以截断撕裂的物理碎片，但绝不把实时开放轮次关闭为中断状态。
+- 缓存属于单个持久化协调器，而不是进程全局 Session map。实时 Session 由现有存储持有，绝不占用准备容量。
+- 新建流程绝不认领相同 id 的冷持久化准备对象。持久化冲突仍会被拒绝。
+- 第三方持久化实现继续获得通过 `load()` 实现的抽象 `prepare()` 回退。它们使用相同发布接口，但只有覆盖准备流程后才能复用精确对象。
+- Revision 校验在复用点和修复提交点建立新鲜性，但不会为后端增加跨进程 writer 排他。持久日志在一次读取与复核往返内保持不变后，重试才能收敛，因此持续的外部写入可能延迟准备。
+
+## 验证
+
+共享持久化契约覆盖无变更且已配平的冷检查与后续修复。`persistence.spec.ts` 与 `preparations.spec.ts` 覆盖同 id 进行中读取共享、检查与准备之间的精确 Session 复用、在历史读取与恢复前由 revision 触发刷新、修复只提交一次、独占预留、设置失败后释放、就绪项 LRU 淘汰、预留期间拒绝 append，以及只允许发布预留 Session。后端测试覆盖完整读取与轻量读取使用同一 revision 身份。agent loop 与 continuable subagent 测试覆盖统一发布流水线，以及取消和拆卸期间从检查到恢复的路径。
+
+## 考虑过的替代方案
+
+**由历史读取激活 agent。** 不采用，因为分页会使仅用于查询的 agent 长期保持实时状态，并把缓存退出问题转移到 agent 生命周期。
+
+**只缓存 `{ meta, events }`。** 不采用，因为恢复仍需从缓存值重新构造、验证、冻结并复制 Session。真正可复用的单元是精确的未发布 Session。
+
+**维护进程全局 Session map。** 不采用，因为它会跨越后端和运行时所有权边界，无界保留身份，并与实时 Session 存储重复。
+
+**在 agent loop 中增加恢复事务或协调器。** 不采用，因为冷读、修复、预留和游标附接都属于持久化与 Session 职责。agent loop 只需要统一的 `SessionPreparation` 所有权边界。
+
+**把 `readFrom()` 改成逻辑准备流程。** 不采用，因为水位消费方需要脱离的物理后缀；对于可寻址后端，还需要限制实际读取范围。恢复平衡与完整 Session 复用具有不同语义。
+
+## 后果
+
+一次冷实体化可以同时服务历史分页、subagent descriptor 检查和后续恢复。所有权转移去除了恢复阶段的冗余复制；每个协调器的有界 LRU 限制内存占用，也避免查询创建实时 agent。新建和恢复共享同一发布协议，同时保持 agent 与 Session 职责分离。
+
+首次冷检查需要承担完整验证与 Session 构造成本，并可能保留该未发布 Session 直至淘汰。持久化层必须协调预留、append、修复和发布；调用方必须把检查结果视为借用的不可变状态。依赖默认 `prepare()` 的后端仍然正确，但无法获得复用优化。
@@ -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/architecture/2026-08-05-slot-declaration-injection.md
+2026-08-05-slot-declaration-injection.md: cb15125977c060144553d7cf75e3c2c26fb1b23b
+2026-08-05-slot-declaration-injection.zh.md: 385cab875bb445ba1ca324fc9b45363b8daf50b6
@@ -0,0 +1,45 @@
+# Agent Note: Slot declaration injection and reload lifetimes
+
+Status: implemented
+
+English | [中文](2026-08-05-slot-declaration-injection.zh.md)
+
+## Problem
+
+Client plugins may contribute to a slot before or after the plugin that declares it. Cordis service injection cannot express this dependency: a service is only an indirect ordering signal, client manifest dependency rows do not sequence activation, and a slot can disappear and return while every related service remains mounted. Registering immediately therefore races an undeclared slot, while waiting on an unrelated service couples independently reloadable features.
+
+Slot-level hot replacement also requires two independent owners. Removing the declaring plugin must remove every contribution under its child slots; removing a contributing plugin must remove only that plugin's entries. A replacement declaration with the same key is a new lifetime even when disappearance and reappearance batch into one notification.
+
+## Decision
+
+`SlotsService.inject(name, callback)` makes the declared slot itself the dependency. The full `SlotMap` key is statically checked; there is no namespace builder, synthetic Cordis service, or slot-specific `Context`. The callback runs immediately when the declaration exists, otherwise waits, and returns either one synchronous disposer or a synchronous iterable of disposers. Iterable effects install transactionally: a later setup failure disposes every earlier yielded effect in reverse order.
+
+The ledger records a declaration epoch distinct from the slot's ordinary entry version. An epoch changes whenever a child declaration is created or collapsed. Injection remembers the active epoch, disposes its callback effect when that epoch ends, and reruns the callback for a replacement declaration even when the final observed state is continuously declared. Ordinary contribution changes do not restart injection.
+
+Both sides retain their natural ownership. The injection controller and every contribution run on the contributing plugin's caller `Context`, so disposing that plugin removes its wait and active entries. The slot ledger's existing child-collapse cascade removes entries when the declarer disappears; injection then runs their disposers to release service-layer resources and remains ready for a later declaration. The declaring plugin's `Context` is neither retained as a capability source nor exposed to contributors.
+
+Dynamic reload code uses an ordinary Cordis plugin fiber as its replacement unit: activate the new module through `ctx.plugin()`, dispose and await the old fiber before mounting its replacement, and let its `slots.inject` and `slots.register` effects leave with that fiber. Renderer subscriptions observe the ledger removal and unmount the component; no slot-owned fiber tree is required.
+
+## Failure and lifecycle contract
+
+An injection whose declaration already exists reports callback setup failures synchronously. A callback failure after a delayed declaration first unsubscribes and rolls back its collected effects, then reports the failure outside the slot notification flush so one registrant cannot starve other listeners. Direct `slots.register()` into an undeclared slot continues to throw: injection is explicit and does not weaken load-time validation.
+
+Disposing an injection is idempotent. It unsubscribes before releasing the active callback effect, preventing teardown-triggered ledger notifications from resurrecting the contribution. Declaration-bound teardown is synchronous with the ledger boundary, so it releases service-layer resources before any subsequent same-tick registration. A waiting injection disposed with its plugin cannot activate later.
+
+## Alternatives considered
+
+**Use `ConversationService` or another service as an ordering barrier.** Service presence does not identify the declaration or follow its reload lifetime, and it creates a false package dependency for presentation-only contributors.
+
+**Bridge each declaration into a `slot:<name>` Cordis service.** This pollutes the service namespace, turns a misspelled dynamic key into a silent service wait, and disguises ledger state as a business capability. Native slot injection provides the same wait without changing Cordis topology.
+
+**Create a Cordis context or fiber for every slot.** A contributor needs the intersection of its own plugin lifetime and the declaration lifetime, not the declarer's capabilities. A slot-owned context introduces capability inheritance and dual-parent teardown problems without improving ledger ownership.
+
+**Make `register()` wait implicitly.** Immediate failure on an undeclared target is a valuable configuration check. Explicit injection distinguishes an intentional independently ordered contribution from a broken composition.
+
+**Judge replacement from `spec(name) !== undefined` alone.** Collapse and redeclaration can batch into one continuously present final state while the old contributions have already been removed. The declaration epoch preserves that boundary.
+
+## Consequences
+
+Slot dependencies become auditable at the registration site and follow declaration replacement without package-specific ordering conventions. Dynamic plugin disposal removes rendered entries through existing Cordis effects, while declaration replacement has a stable hook for later slot-level HMR.
+
+The runtime carries one additional monotonic epoch per touched slot and injection callbacks must return their cleanup. Multi-registration callbacks use iterable effects so setup and teardown remain atomic. The flat dotted-key ledger and the single `register()` composition authority remain unchanged.
@@ -0,0 +1,45 @@
+# Agent Note（agent 决策记录）：slot 声明注入与重载生命周期
+
+Status: implemented
+
+[English](2026-08-05-slot-declaration-injection.md) | 中文
+
+## 问题
+
+客户端插件可能在声明某个 slot 的插件之前或之后向该 slot 贡献内容。Cordis 服务注入无法表达这种依赖：服务只能作为间接的顺序信号；客户端 manifest（元数据清单）的依赖项不会规定激活顺序；即使所有相关服务始终挂载，slot 仍可能消失后重新出现。因此，立即注册会与尚未声明的 slot 形成竞态，而等待无关服务则会耦合本可独立重载的功能。
+
+slot 级热替换还要求两个相互独立的所有者。移除声明方插件必须移除其子 slot 下的所有贡献；移除贡献方插件只能移除该插件自己的条目。即使消失与重新出现合并在同一次通知中，同一个 key 的替换声明也属于新的生命周期。
+
+## 决策
+
+`SlotsService.inject(name, callback)` 以已声明的 slot 本身作为依赖。完整的 `SlotMap` key 会经过静态检查；系统不引入命名空间构建器、合成的 Cordis 服务或 slot 专属 `Context`。声明存在时回调同步执行，否则等待；回调返回一个同步 disposer，或由多个 disposer 构成的同步 iterable。iterable effect 的安装具有事务性：后续 setup 失败时，系统会按逆序 dispose（资源释放）之前 yield 的所有 effect。
+
+该账本记录独立于 slot 普通条目版本的 declaration epoch（声明代次）。每当子声明创建或折叠时，epoch 都会变化。注入会记住活跃 epoch；该 epoch 结束时，注入会 dispose 其回调 effect；即使最终观测到的状态始终为已声明，也会为替换声明重新执行回调。普通贡献变更不会重启注入。
+
+声明方与贡献方各自保留其自然所有权。注入控制器和每项贡献都运行在贡献方插件调用时的 `Context` 上，因此 dispose 该插件会同时移除其等待与活跃条目。slot 账本现有的子项折叠级联会在声明方消失时移除条目；随后，注入会运行其 disposer 以释放服务层资源，并继续等待后续声明。系统既不会将声明方插件的 `Context` 保留为 capability 来源，也不会向贡献方公开它。
+
+动态重载代码使用普通 Cordis 插件 fiber 作为替换单元：通过 `ctx.plugin()` 激活新模块；挂载替换模块之前，先 dispose 并等待旧 fiber；该 fiber 的 `slots.inject` 与 `slots.register` effect 会随之退出。renderer 订阅会观察到账本移除并卸载组件；无需建立 slot 自有的 fiber 树。
+
+## 失败与生命周期契约
+
+如果注入创建时声明已经存在，回调 setup 失败会同步上报。延迟声明出现后发生的回调失败，会先取消订阅并回滚已收集的 effect，再在 slot 通知刷新之外上报，避免一个注册方使其他 listener 得不到执行机会。直接调用 `slots.register()` 向未声明 slot 注册仍会抛出异常：注入是显式机制，不会削弱加载时验证。
+
+对注入执行 dispose 具有幂等性。它会先取消订阅，再释放活跃的回调 effect，避免拆卸触发的账本通知复活该项贡献。声明绑定的 teardown 与账本边界同步，因此会在同一 tick 的任何后续注册之前释放服务层资源。随插件一同 dispose 的待命注入无法在之后激活。
+
+## 备选方案
+
+**将 `ConversationService` 或其他服务用作顺序屏障。** 服务存在并不能标识相应声明，也不会跟随声明的重载生命周期；只负责呈现的贡献方还会因此产生虚假的包（package）依赖。
+
+**将每项声明桥接为 `slot:<name>` Cordis 服务。** 这会污染服务命名空间，使拼错的动态 key 变成静默的服务等待，并把账本状态伪装成业务 capability。原生 slot 注入无需改变 Cordis 拓扑，即可提供同样的等待能力。
+
+**为每个 slot 创建 Cordis 上下文或 fiber。** 贡献方需要的是自身插件生命周期与声明生命周期的交集，而不是声明方的 capability。slot 所有的上下文会引入 capability 继承和双父级拆卸问题，却无法改善账本所有权。
+
+**让 `register()` 隐式等待。** 对未声明目标立即失败是一项有价值的配置检查。显式注入能够区分有意独立排序的贡献与错误组合。
+
+**只根据 `spec(name) !== undefined` 判断替换。** 折叠与重新声明可以合并成一个最终状态始终存在的通知，而旧贡献此时已经被移除。declaration epoch 保留了这条生命周期边界。
+
+## 影响
+
+slot 依赖可以在注册点审计，并且无需特定于包的顺序约定即可跟随声明替换。动态插件 dispose 会通过既有 Cordis effect 移除已渲染条目，而声明替换则为后续 slot 级 HMR（热模块替换）提供稳定钩子。
+
+运行时为每个被访问的 slot 多维护一个单调 epoch，且注入回调必须返回清理操作。多注册回调使用 iterable effect，使 setup 与 teardown 保持原子性。扁平的点分 key 账本和唯一的 `register()` 组合权威保持不变。
@@ -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/2026-08-05-context-meter-blind-to-compaction.md
+2026-08-05-context-meter-blind-to-compaction.md: ab39ae4e109f238960fd60de5e5b61075344f525
+2026-08-05-context-meter-blind-to-compaction.zh.md: c93aa509530e48acf906b18ba85bab4c7d355d69
@@ -0,0 +1,46 @@
+# Agent Note: the context meter could not see a compaction
+
+Status: implemented
+
+English | [中文](2026-08-05-context-meter-blind-to-compaction.zh.md)
+
+## Problem
+
+The composer's [context meter](../feature/2026-08-05-composer-context-meter-breakdown.md) took its ring, percentage, and `~used / capacity` header from `contextPressure.pressureTokens`, the newest provider-reported prompt size. That number moves only when a request reports usage, and compaction reports none: `compact-basic` summarizes through a direct `ctx.llm.stream()` call and appends `compact/start`, `compact/summary`, the replacement `user/message`, and `compact/end` — no `assistant/message`, no usage chunk.
+
+So the meter was frozen across the one action taken to change it. Driving a real `compactNow` through the agent loop:
+
+```
+BEFORE compact:  ring=4%  header=~4227/100000   rows=[system 18, tools 0, messages 4365]
+AFTER  compact:  ring=4%  header=~4227/100000   rows=[system 18, tools 0, messages  286]
+```
+
+The composition rows, which fold the surface, dropped by 93%. The ring — the primary affordance, and the reason a user opens the panel right after compacting — did not move at all, and would not until an entire further turn completed. The panel then showed a header and rows disagreeing by more than an order of magnitude, at exactly the moment a reader was most likely to add the rows up.
+
+## Decision
+
+`contextPressure` publishes a second numerator, `projectedTokens`: the provider sample plus the heuristic repricing of everything the surface gained or lost since that sample was taken, clamped at zero. The fold carries the priced surface through the shared `surface-fold.ts` and stamps `sampledSurfaceTokens` when a usage sample lands — **before** the same event joins the surface, so an `assistant/message` anchors against the surface its own request actually carried. `stateVersion` moves to 3.
+
+Only the delta is estimated. The anchor stays provider-exact, which keeps the estimator's systematic CJK and JSON-schema underpricing out of the occupancy figure while still letting the number react the moment content lands or a span is shadowed. `contextOccupancy` reads `projectedTokens` and falls back to the bare sample, so a projection restored from a pre-field checkpoint degrades to the old behavior instead of vanishing.
+
+This reverses the "the ring, header, and bar length stay provider-exact" half of the [context meter decision](../feature/2026-08-05-composer-context-meter-breakdown.md). What that decision was protecting — not fabricating precision by scaling heuristic rows to a provider total — is preserved: the rows are still unscaled, and the header still does not equal their sum. What changed is the recognition that "provider-exact but describing a request two compactions ago" is not the more truthful figure.
+
+## Alternatives considered
+
+**Project `measure().totalTokens` instead.** The measurement service already composes exactly this (`baseline` anchor plus signed `surfaceDeltaTokens`), and it reacts correctly — measured at 4383 → 304 across the same compaction. But it is a service over private replay state, not a pure fold, and a projection cannot call it. Reproducing its anchor inside a `ProjectionDefinition` needs `_estimateProviderAssistant`'s random access to the chunk provenance (`session.events[seq]`), which `apply(state, event)` does not have. Anchoring on the sampled surface total is the same idea reachable from a pure per-event fold.
+
+**Emit a synthetic usage record at the end of compaction.** Would move `pressureTokens` itself, but the only usage compaction holds is the summarization request's own — a different prompt entirely. Recording it as the conversation's prompt size would be a lie in the durable log rather than in one display.
+
+**Let the UI subtract, exposing `sampledSurfaceTokens` and reading `contextBreakdown.messageTokens`.** Splits one figure's arithmetic across two projections and the client. The host owns the vocabulary; it should publish the whole value.
+
+## Consequences
+
+Occupancy now advances with every surface event rather than once per turn, so the ring creeps up as a turn produces tool results instead of jumping at its end — and drops the instant a compaction lands. That is more projection frames on the wire: one per surface event for `contextPressure`, the rate `contextBreakdown` already ran at.
+
+The panel's composition rows still do not sum to the header, and now for one clearly-stated reason instead of two: the rows carry the estimator's error, the header's anchor does not. The remaining lever is estimator accuracy (CJK-aware weighting in `estimate.ts`), which changes no seam.
+
+`sampledSurfaceTokens` assumes nothing joins the surface between a step's request and its usage report. The loop admits steering and context before `buildRequest` and drains tool results after `assistant/message`, so that holds; if it ever stops holding, the error is bounded by one message and self-corrects at the next sample.
+
+## Testing
+
+`packages/llm/token-meter/tests/token-usage-projection.spec.ts` covers the carry-forward across surface growth and a compaction (the sample holding still while the projection shrinks) and the zero clamp when heuristic error would drive the figure negative. `packages/client/ui-conversation/tests/context-meter.spec.tsx` pins the ring reading the projected figure, and `chat-stats-bash-sample.spec.tsx` pins `contextOccupancy`'s preference and its fallback. The end-to-end numbers above came from driving `BasicCompactService.compactNow` through a real `AgentLoop` with the projection registry mounted.
@@ -0,0 +1,46 @@
+# Agent Note：上下文仪表看不见压缩
+
+Status: implemented
+
+[English](2026-08-05-context-meter-blind-to-compaction.md) | 中文
+
+## 问题
+
+composer 的[上下文仪表](../feature/2026-08-05-composer-context-meter-breakdown.md)的圆环、百分比与 `~已用 / 容量` 标题都取自 `contextPressure.pressureTokens`，即提供方报告的最新提示词规模。这个数字只在某个请求报告用量时才会移动，而压缩不报告用量：`compact-basic` 通过直连的 `ctx.llm.stream()` 调用生成摘要，只追加 `compact/start`、`compact/summary`、用作替换的 `user/message` 和 `compact/end`——没有 `assistant/message`，也没有用量分片。
+
+于是在唯一一个专门用来改变它的操作面前，这块仪表纹丝不动。通过真实 agent loop 驱动一次 `compactNow`：
+
+```
+BEFORE compact:  ring=4%  header=~4227/100000   rows=[system 18, tools 0, messages 4365]
+AFTER  compact:  ring=4%  header=~4227/100000   rows=[system 18, tools 0, messages  286]
+```
+
+折叠表层得出的组成明细行下降了 93%。而圆环——那个主要的可操作元素，也正是用户压缩完立刻会去点开面板的理由——完全没动，而且要等到又跑完一整轮才会动。此时面板上的标题与明细行相差一个数量级以上，恰恰发生在读者最可能去把明细行加总的时刻。
+
+## 决策
+
+`contextPressure` 发布第二个分子 `projectedTokens`：在提供方样本之上，加上自取样以来表层增减部分的启发式重新计价，下界钳制为零。该折叠通过共享的 `surface-fold.ts` 携带已计价的表层，并在用量样本落地时记下 `sampledSurfaceTokens`——记录时机在同一条事件加入表层**之前**，因此 `assistant/message` 锚定的正是它自己那次请求实际携带的表层。`stateVersion` 提升到 3。
+
+只有增量部分是估算的。锚点保持提供方精确值，从而把估算器对 CJK 文本与 JSON schema 的系统性低估挡在占用率数字之外，同时又让这个数字能在内容落地或某段区间被遮蔽的瞬间做出反应。`contextOccupancy` 读取 `projectedTokens`，并回退到裸样本，因此从不含该字段的检查点恢复出来的投影会退化为旧行为，而不是直接消失。
+
+这推翻了[上下文仪表决策](../feature/2026-08-05-composer-context-meter-breakdown.md)中「圆环、标题与进度条总长保持提供方精确值」的那一半。那条决策真正想守住的东西——不要把启发式明细行按比例缩放到提供方总量、从而伪造精度——依然守住了：明细行仍未被缩放，标题仍不等于它们之和。改变的是这样一个认识：「提供方精确、但描述的是两次压缩之前那个请求」并不是更真实的数字。
+
+## 备选方案
+
+**改为投影 `measure().totalTokens`。** 测量服务本来就合成了正是这个量（`baseline` 锚点加有符号的 `surfaceDeltaTokens`），而且反应正确——同一次压缩前后实测为 4383 → 304。但它是一个建立在私有重放状态上的服务，不是纯折叠，投影无法调用它。要在 `ProjectionDefinition` 内部复现它的锚点，需要 `_estimateProviderAssistant` 对分片来源的随机访问（`session.events[seq]`），而 `apply(state, event)` 拿不到。以取样时的表层总量作为锚点，是同一个思路在纯逐事件折叠中可达的版本。
+
+**在压缩结束时补写一条合成的用量记录。** 这确实能推动 `pressureTokens` 本身，但压缩手上唯一的用量是摘要请求自己的用量——那是完全另一个提示词。把它记成本对话的提示词规模，等于把谎言写进持久日志，而不只是写进某一处展示。
+
+**让 UI 自己做减法：暴露 `sampledSurfaceTokens`，再读 `contextBreakdown.messageTokens`。** 这会把一个数字的算术拆散到两个投影和客户端三处。词汇的所有者是宿主，就应当由它发布完整值。
+
+## 影响
+
+占用率现在随每个表层事件推进，而不再是每轮跳一次，因此一轮中产生工具结果时圆环会持续爬升，而不是等到轮次结束才跳变——压缩落地的瞬间它也会掉下来。代价是线路上多了投影帧：`contextPressure` 每个表层事件推一帧，也就是 `contextBreakdown` 本来就在跑的频率。
+
+面板的组成明细行仍然加不出标题数字，但现在只剩一个能讲清楚的原因，而不是两个：明细行带着估算器的误差，标题的锚点不带。剩下的抓手是估算精度（在 `estimate.ts` 里做 CJK 感知加权），它不改动任何 seam。
+
+`sampledSurfaceTokens` 依赖一个前提：在某个步骤的请求与它的用量报告之间，不会有新内容加入表层。循环在 `buildRequest` 之前接纳 steering 与 context，在 `assistant/message` 之后才排空工具结果，因此该前提成立；即便将来不再成立，误差也被限制在一条消息以内，并在下一个样本处自行纠正。
+
+## 测试
+
+`packages/llm/token-meter/tests/token-usage-projection.spec.ts` 覆盖了样本在表层增长与一次压缩上的推进（样本保持不动而投影值缩小），以及启发式误差会把数字压到负数时的零钳制。`packages/client/ui-conversation/tests/context-meter.spec.tsx` 钉住圆环读取投影值这一点，`chat-stats-bash-sample.spec.tsx` 钉住 `contextOccupancy` 的优先级与回退。上面那组端到端数字来自在挂载了投影注册表的真实 `AgentLoop` 上驱动 `BasicCompactService.compactNow`。
@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write .agents/notes/implemented/feature/2026-07-23-web-todo-display.md
-2026-07-23-web-todo-display.md: 7223ff9adbf1fa6dca39c9eb4949b6d3861bdd6d
-2026-07-23-web-todo-display.zh.md: 98390c8c2cd95be9d5565b4062d00c1d99215cea
+2026-07-23-web-todo-display.md: d5939c0fa6ab83a61f1932622c4b6a150ccaded7
+2026-07-23-web-todo-display.zh.md: b1ecf679efe81016e00c5c1221c04730b3ce98bb
@@ -18,11 +18,11 @@ Consume `todo/write` as a Session side effect, not a surface node, and render it

 ### TodoPanel: the durable list as a persistent strip

-The panel mounts through the `conversation.input.dock` slot (a plain registrant plugin, `todoDockEntry`, the QueueDock posture: `inject: ['slots', 'conversation']` as the load-order seam, `order: -1` above the queue rows), hidden while empty, collapsible to a header of title + `"<done>/<total> tasks · <n> in progress"` (no in-progress content hint when collapsed). Status glyphs are the figma todo set (green check ring / blue fading ring / dashed pending ring) on a tip-surface card (`--dsw-specific-tip`, 14px radius, `width: calc(100% - 88px)` / `max-width: 776px` centered; InputBar top pad 6px is the gap to the composer card). It reads `snapshot.todos` via the standard-kit `useSession` hook the dock entry receives — no store, no service, no ctx. The inner component stays props-complete and framework-free; the dock adapter is a one-line wrapper.
+The panel mounts through the `conversation.input.dock` slot (a plain registrant plugin, `todoDockEntry`, using `ctx.slots.inject` with no `ConversationService` edge, `order: -1` above the queue rows), hidden while empty, collapsible to a header of title + `"<done>/<total> tasks · <n> in progress"` (no in-progress content hint when collapsed). Status glyphs are the figma todo set (green check ring / blue fading ring / dashed pending ring) on a tip-surface card (`--dsw-specific-tip`, 14px radius, `width: calc(100% - 88px)` / `max-width: 776px` centered; InputBar top pad 6px is the gap to the composer card). It reads `snapshot.todos` via the standard-kit `useSession` hook the dock entry receives — no store, no service, no ctx. The inner component stays props-complete and framework-free; the dock adapter is a one-line wrapper.

 ### TodoRow: the per-call row through the keyed toolview slot

-The dedicated `todo_write` chat row is a plain registrant plugin (`todoToolview`, mounted from `apply`) that registers into the keyed `conversation.chat.toolview` slot via `ctx.slots.register` — the same seam and load-order posture as the bash sample (`inject: ['slots', 'conversation']`), but a product registration. The summary derives from call args (`N/M done · active item`); unparseable args fall back to the generic row summary; clicking opens the details column with the raw args. No `ToolEventView` is added for todo — presentation is client-owned, and the durable list renders from the session event, not the tool card.
+The dedicated `todo_write` chat row is a plain registrant plugin (`todoToolview`, mounted from `apply`) that registers into the keyed `conversation.chat.toolview` slot through `ctx.slots.inject`, the same declaration-lifetime posture as the bash sample but a product registration. The summary derives from call args (`N/M done · active item`); unparseable args fall back to the generic row summary; clicking opens the details column with the raw args. No `ToolEventView` is added for todo — presentation is client-owned, and the durable list renders from the session event, not the tool card.

 ## Alternatives considered

@@ -18,11 +18,11 @@ Status: implemented

 ### TodoPanel：持久化列表作为一条常驻横条

-面板经 `conversation.input.dock` slot 挂载（普通注册者插件 `todoDockEntry`，采用与 QueueDock 相同的模式：以 `inject: ['slots', 'conversation']` 作为加载顺序 seam，`order: -1` 排在队列条上方），空列表时隐藏，可折叠为标题加 `"<已完成>/<总数> tasks · <n> in progress"` 的表头（折叠态不显示进行中条目的内容提示）。状态图标为 figma todo 套件（绿色勾选环／蓝色渐隐环／虚线未开始环），卡片使用 tip 表面（`--dsw-specific-tip`、14px 圆角、`width: calc(100% - 88px)`／`max-width: 776px` 居中；InputBar 顶部 6px 内边距是到输入卡的间距）。它经 dock entry 收到的标准件 `useSession` hook 读取 `snapshot.todos`——无 store、无 service、无 ctx。内部组件保持 props 完备且框架无关；dock 适配器只是一行包装。
+面板经 `conversation.input.dock` slot 挂载（普通注册者插件 `todoDockEntry` 使用 `ctx.slots.inject`，不依赖 `ConversationService`，`order: -1` 排在队列条上方），空列表时隐藏，可折叠为标题加 `"<已完成>/<总数> tasks · <n> in progress"` 的表头（折叠态不再附带进行中条目正文）。状态图标为 figma todo 套件（绿色勾选环／蓝色渐隐环／虚线未开始环），卡片使用 tip 表面（`--dsw-specific-tip`、14px 圆角、`width: calc(100% - 88px)`／`max-width: 776px` 居中；InputBar 顶部 6px 内边距是到输入卡的间距）。它经 dock entry 收到的标准件 `useSession` hook 读取 `snapshot.todos`——无 store、无 service、无 ctx。内部组件保持 props 完备且框架无关；dock 适配件只是一行包装。

 ### TodoRow：经 keyed toolview slot 的逐调用行

-专用的 `todo_write` 对话行是一个普通注册者插件（`todoToolview`，由 `apply` 挂载），经 `ctx.slots.register` 注册进 keyed 的 `conversation.chat.toolview` slot——与 bash 样例使用同一 seam、相同的加载顺序模式（`inject: ['slots', 'conversation']`），但属产品级注册。摘要由调用 args 推导（`N/M done · active item`）；无法解析的 args 回退到通用行摘要；点击会以原始 args 打开 details 列。todo 不新增任何 `ToolEventView`——呈现归客户端所有，持久化列表从会话事件渲染，而非工具卡。
+专用的 `todo_write` 对话行是一个普通注册者插件（`todoToolview`，由 `apply` 挂载），经 `ctx.slots.inject` 注册进 keyed 的 `conversation.chat.toolview` slot，遵循与 bash 样例相同的声明生命周期，但属产品级注册。摘要由调用 args 推导（`N/M done · active item`）；无法解析的 args 回退到通用行摘要；点击会以原始 args 打开 details 列。todo 不新增任何 `ToolEventView`——呈现归客户端所有，常驻列表从会话事件渲染，而非工具卡。

 ## 考虑过的替代方案

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write .agents/notes/implemented/feature/2026-07-30-deepseek-onboarding-credential-setup.md
-2026-07-30-deepseek-onboarding-credential-setup.md: ed53ffe64d3ba27e8746d58ad84d1a4c401f6ce4
-2026-07-30-deepseek-onboarding-credential-setup.zh.md: 340728ab9348e0132954e403f9bdbf561e340247
+2026-07-30-deepseek-onboarding-credential-setup.md: c732758bc567376a0be4ac348aa9129aa8126ac4
+2026-07-30-deepseek-onboarding-credential-setup.zh.md: 2dc7e0ccf5f9a99ad35c859a7ecfb9f98d93d530
@@ -12,7 +12,7 @@ The [web configuration plane](../architecture/2026-07-30-web-config-plane.md) ma

 **One readiness projection owns both Models and onboarding facts.** `ui-models` keeps a single store that joins `llm.providers({})`, redacted `settings.describe({})`, and batched `credentials.describe({refs})`. The onboarding projection selects the `deepseek-official` configurable-provider entry owned by the `llm-deepseek` namespace and empty settings path, reads the effective `apiKeyEnv`, and evaluates the matching credential descriptor. A live route with the same provider id but no matching configurable-provider declaration is adapter-absent for onboarding. A configured literal `apiKey` secret sidecar is also ready, so compatibility configuration does not trigger a false prompt; a configured process-environment credential is ready and remains read-only.

-**The settings shell contributes ordering and navigation, not provider policy.** `ui-settings` declares a root-scoped `settings.onboarding` list slot and mounts one ordered step at a time while the current surface is the empty Hero. The active registrant receives `complete()` and a private `openSection(id)` callback; completion transfers ownership to the next entry. `ui-models` registers the DeepSeek step through the same declaration-aware deferred-registration path as its Models section, so plugin load order does not become a contract and independently contributed dialogs cannot stack. The product-wide welcome step that precedes it is owned separately by [the versioned welcome decision](2026-07-30-versioned-gui-welcome-onboarding.md).
+**The settings shell contributes ordering and navigation, not provider policy.** `ui-settings` declares a root-scoped `settings.onboarding` list slot and mounts one ordered step at a time while the current surface is the empty Hero. The active registrant receives `complete()` and a private `openSection(id)` callback; completion transfers ownership to the next entry. `ui-models` registers the DeepSeek step and its Models section through `slots.inject()`, so each contribution follows its declaration lifetime without making plugin load order a contract, and independently contributed dialogs cannot stack. The product-wide welcome step that precedes it is owned separately by [the versioned welcome decision](2026-07-30-versioned-gui-welcome-onboarding.md).

 **The prompt routes to the one credential editor.** A mounted, active adapter with a resolved, writable, unconfigured reference presents one action that opens Settings on Models. The existing DeepSeek setup card there exclusively owns the password input, `credentials.set({ref, value})`, write failures, and post-write refresh; the onboarding overlay never holds or submits a secret. An unavailable settings or credential capability keeps its deployment diagnostic and routes to the same page, while an absent adapter remains skipped because navigation cannot mount a Cordis plugin.

@@ -12,7 +12,7 @@ Status: implemented

 **Models 与首次使用引导共享同一个就绪状态投影。**`ui-models` 维护一个 store，把 `llm.providers({})`、脱敏后的 `settings.describe({})` 和批量调用的 `credentials.describe({refs})` 联接为同一份状态。首次使用投影选取由 `llm-deepseek` namespace 与空 settings path 持有的 `deepseek-official` 可配置提供方条目，读取生效的 `apiKeyEnv`，并检查对应的凭据描述符。同 provider id 但没有匹配可配置提供方声明的存活路由，在首次使用引导中视为适配器缺失。若 `apiKey` 字面量对应的 secret 槽位标记为已设置，也会判定为就绪，兼容配置因此不会误触发页面；通过进程环境提供的凭据若已配置，同样判定为就绪并保持只读。

-**设置外壳只贡献排序与导航，不持有提供方策略。** `ui-settings` 声明一个根作用域的 `settings.onboarding` list slot，并在当前界面为空白 Hero 时，每次只挂载一个有序步骤。当前注册方会收到 `complete()` 和私有 `openSection(id)` 回调；完成当前步骤后，所有权转交给下一项。`ui-models` 沿用 Models 分区所使用、感知 slot 声明的延迟注册路径来注册 DeepSeek 步骤，因此插件加载顺序不会成为契约，独立贡献的对话框也无法堆叠。排在它之前的产品级欢迎步骤由[版本化欢迎决策](2026-07-30-versioned-gui-welcome-onboarding.md)单独持有。
+**设置外壳只贡献排序与导航，不持有提供方策略。** `ui-settings` 声明一个根作用域的 `settings.onboarding` list slot，并在当前界面为空白 Hero 时，每次只挂载一个有序步骤。当前注册方会收到 `complete()` 和私有 `openSection(id)` 回调；完成当前步骤后，所有权转交给下一项。`ui-models` 通过 `slots.inject()` 注册 DeepSeek 步骤及其 Models 分区，使每项贡献都跟随自身的声明生命周期，不让插件加载顺序成为契约；独立贡献的对话框也无法堆叠。排在它之前的产品级欢迎步骤由[版本化欢迎决策](2026-07-30-versioned-gui-welcome-onboarding.md)单独持有。

 **首次使用页面只负责跳转到唯一的凭据编辑器。**适配器已挂载且处于活跃状态，其引用可解析、可写但尚未配置时，界面会显示一个操作按钮，用于打开「设置」的 Models 分区。该分区已有的 DeepSeek 设置卡片全权负责密码输入框、`credentials.set({ref, value})`、写入失败处理和写入后刷新；首次使用页面绝不持有或提交 secret。

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write .agents/notes/implemented/feature/2026-07-30-web-read-card-frontend.md
-2026-07-30-web-read-card-frontend.md: f504cab7705d03f6d3e911da05c509da50bb9abe
-2026-07-30-web-read-card-frontend.zh.md: 983e03b36a3e6d6d4ec0ba416fdcca227d82bb41
+2026-07-30-web-read-card-frontend.md: 06559d70c655b86a6aa70c8a9e948f4f21a1f522
+2026-07-30-web-read-card-frontend.zh.md: 92fb724658d4c23b915f61efc3b482fdf1ce7c7b
@@ -16,7 +16,7 @@ The [read backend](2026-07-30-web-read-card.md) added a fourth render-intent car

 `readCardModel` is result-side only, mirroring the backend: a read call carries no content until `execute` returns, so the pending call stays a `GenericCallView` (`kind: 'read'`) and this returns null for a running read — the row keeps its args-derived summary until the result arrives. It also returns null for a settled call whose result view is not a read card, including a `card` value this UI version does not know (which arrives over the wire and cannot be trusted to be a compiled variant) and the read tool's own generic fallback for an error result. The card's banner label is the read view's `title` when the tool supplied one (the contract's replacement-title rule), otherwise the file path relativized to the session workspace so a workspace-rooted absolute path shows the same short form the row summary shows. The model copies the frozen line array into the primitive's own line shape, so the card never holds a reference into the runtime's snapshot cache.

-The chat row renders the card **resident** under the summary line, capped at `CHAT_READ_MAX_LINES` (8, half the primitive's default), the same posture `BashRow` gives a terminal card — the block's internal expander keeps a long read from taking over the message flow. Two render sites carry it: the keyed `ReadRow` (registered under `read` in `apply.ts`, the load-order seam being `inject: ['slots', 'conversation']` exactly as the bash sample) whose summary is the file path as an openable host link, and `GenericToolCard`'s fallback for a read-declaring tool without its own keyed row (e.g. `web_fetch`, which classifies to the `read` variant). The details panel renders the same card at the primitive's own full-height cap (16), because the panel is the single-call reading surface.
+The chat row renders the card **resident** under the summary line, capped at `CHAT_READ_MAX_LINES` (8, half the primitive's default), the same posture `BashRow` gives a terminal card — the block's internal expander keeps a long read from taking over the message flow. Two render sites carry it: the keyed `ReadRow` (registered under `read` through `ctx.slots.inject`, exactly as the bash sample) whose summary is the file path as an openable host link, and `GenericToolCard`'s fallback for a read-declaring tool without its own keyed row (e.g. `web_fetch`, which classifies to the `read` variant). The details panel renders the same card at the primitive's own full-height cap (16), because the panel is the single-call reading surface.

 Whole-row collapse/expand (defaulting every tool call to collapsed) is a separate later change that will flip every resident card at once; this note's card is resident, matching the terminal card it sits beside.

@@ -16,7 +16,7 @@ Status: implemented

 `readCardModel` 只在结果侧，与后端对称：一次读取调用在 `execute` 返回前不带任何内容，因此挂起中的调用保持为 `GenericCallView`（`kind: 'read'`），本函数对运行中的读取返回 null —— 该行保持其从参数派生的摘要，直到结果到达。它对结果视图不是读取卡片的已结算调用也返回 null，包括本 UI 版本不认识的 `card` 值（它从线路到来、不能被信任为一个已编译的变体）以及读取工具对错误结果自己的通用回退。卡片横幅标签在工具提供 `title` 时取它（契约的替换标题规则），否则取相对于会话工作区化简后的文件路径，使工作区根下的绝对路径显示为与行摘要相同的短形式。该 model 把冻结的行数组复制进 primitive 自己的行形状，因此卡片绝不持有指向运行时快照缓存的引用。

-聊天行把卡片**常驻**渲染在摘要行之下，上限 `CHAT_READ_MAX_LINES`（8，是 primitive 默认值的一半），与 `BashRow` 对终端卡片的姿态相同 —— block 的内部展开器让长读取不会占据整个消息流。两个渲染点承载它：keyed `ReadRow`（在 `apply.ts` 里以 `read` 键注册，加载顺序 seam 为 `inject: ['slots', 'conversation']`，与 bash 样例完全一致），其摘要是作为可打开的宿主链接的文件路径；以及 `GenericToolCard` 对没有自己 keyed 行的读取声明工具（例如归到 `read` 变体的 `web_fetch`）的回退。详情面板以 primitive 自己的全高上限（16）渲染同一张卡片，因为面板是单次调用的阅读界面。
+聊天行把卡片**常驻**渲染在摘要行之下，上限 `CHAT_READ_MAX_LINES`（8，是 primitive 默认值的一半），与 `BashRow` 对终端卡片的姿态相同 —— block 的内部展开器让长读取不会占据整个消息流。两个渲染点承载它：keyed `ReadRow`（经 `ctx.slots.inject` 以 `read` 键注册，与 bash 样例完全一致），其摘要是作为可打开的宿主链接的文件路径；以及 `GenericToolCard` 对没有自己 keyed 行的读取声明工具（例如归到 `read` 变体的 `web_fetch`）的回退。详情面板以 primitive 自己的全高上限（16）渲染同一张卡片，因为面板是单次调用的阅读界面。

 整行折叠/展开（把每个工具调用默认折叠）是一个单独的后续改动，它会一次性翻转每张常驻卡片；本 note 的卡片是常驻的，与它旁边的终端卡片一致。

@@ -0,0 +1,6 @@
+# Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
+# side as of the last confirmed-consistent state. Both languages carry equal authority;
+# after editing either side, bring the other along and re-record with:
+#   pnpm run verify-translation-pairing --write .agents/notes/implemented/feature/2026-08-04-web-latency-throughput-metrics.md
+2026-08-04-web-latency-throughput-metrics.md: 4d7627a9a38127259f1ba07121cea7282f794f2e
+2026-08-04-web-latency-throughput-metrics.zh.md: 09e59242b799a3f4d03b9e0259f1a5a0d85f6a53
@@ -0,0 +1,31 @@
+# Agent Note: Web turn and window latency/throughput metrics
+
+Status: implemented
+
+English | [中文](2026-08-04-web-latency-throughput-metrics.zh.md)
+
+## Problem
+
+The Web chat records per-step LLM timing (`stepStartTime` / `firstTokenTime` / `completedTime`) and per-step usage, and the trajectory view exposes them per step, but the chat surface answers neither "how responsive was this turn" nor "how fast is this session going": the assistant footer shows only the turn wall time, and the stats line folds only wall-time totals.
+
+## Decision
+
+A package-local fold, `ui-conversation`'s `chat/turn-metrics.ts`, is the single derivation from assistant nodes to latency/throughput readings. `assistantStepReading` turns one node into a step reading: TTFT needs both `stepStartTime` and `firstTokenTime`, decode span needs `firstTokenTime`, negative spans clamp to zero, and output tokens come from the untrusted `usage` value only when they are finite and non-negative. `deriveTurnMetrics` folds readings per turn: the lowest-numbered step owns the turn's TTFT slot, and throughput divides the summed output tokens by the summed decode spans over exactly the steps carrying both, so an unsampled step drops out instead of skewing the ratio; a turn with neither figure emits no entry.
+
+The assistant footer appends the readings to the existing hover-revealed time chrome after `Ran for`, as `TTFT {s}s · {tps} tok/s`, each omitted independently when unrecorded. ChatView shows a turn's readings only when that turn's `turnTimings` entry has an `endTime`: the loaded window is a contiguous log suffix, so an in-window settled turn carries every one of its steps and the first-step TTFT is genuine rather than a window artifact. `formatLatencySeconds` is unit-less so each locale template owns its second suffix (`TTFT {seconds}s` / `首 token {seconds}秒`).
+
+The stats line reuses the same step reading in its window fold: `deriveStats` accumulates TTFT sum/count and decode span/tokens, rendering a latency/throughput group localized through the `conversation` locale namespace (`TTFT avg … · … tok/s` in English) beside the LLM/tool wall times. The turn-count, step-count, duration, cache, and token labels use the same namespace. Like those wall times the group is window-scoped and folds no billing; token accounting stays on the token-meter projections.
+
+## Alternatives considered
+
+**A durable session projection (token-meter shape).** A `ProjectionDefinition` folding step timings host-side would survive compaction and window paging and cover the whole log. Deferred, not rejected: projection state must stay O(1) (averages, not percentiles), it needs a host change plus a schema, and the chat stats line is already documented as window-scoped for its duration facts — the new group joins that scope. A later PR can add the durable projection without moving these readings.
+
+**Per-step footer chrome.** Showing each assistant message its own TTFT would attach chrome to mid-turn narration nodes, which the footer design deliberately keeps chrome-free; the trajectory view already exposes per-step timing detail.
+
+**Gating footer metrics on node presence instead of `turn/end` timing.** Rendering whatever steps happen to be loaded would show a plausible-looking TTFT that is actually the first *loaded* step after paging. The `endTime` gate plus the suffix-window invariant makes the displayed figure the turn's true first-step latency or nothing.
+
+## Consequences
+
+A settled in-window turn's footer reveals `TTFT`/`tok/s` on hover after the wall time, and the stats line shows window-average latency and throughput with localized labels beside its wall times, all without new session events or host changes. Metrics degrade by omission: providers or steps without timing or usage samples drop individual figures rather than rendering zeros. Older history outside the loaded window stays uncounted, recorded in the package README's stats-line limitation.
+
+Both readings divide by measured wall time, so neither is reproducible: the same replayed scenario yielded 69 and 70 tok/s on consecutive local runs, and a 3 ms replayed stream reads 26333 tok/s. The Web aria goldens therefore normalize throughput to `{{throughput}}` beside the existing `{{duration}}`, and the footer's decorative separators gained flanking spaces — without them the readings concatenate into one accessible string (`Ran for 13sTTFT 0.2s12 tok/s`), which both loses the reading boundaries a screen reader needs and denies `{{duration}}` the word boundary it matches on.
@@ -0,0 +1,31 @@
+# Agent Note: Web 轮次与窗口级延迟/吞吐指标
+
+Status: implemented
+
+[English](2026-08-04-web-latency-throughput-metrics.md) | 中文
+
+## 问题
+
+Web 聊天已经记录了逐步骤的 LLM 计时（`stepStartTime`／`firstTokenTime`／`completedTime`）和逐步骤 usage，trajectory 视图也按步骤展示它们，但聊天界面既回答不了「这一轮响应有多快」，也回答不了「这个会话跑得有多快」：assistant 页脚只显示轮次实际耗时，统计行也只折算墙钟时间总量。
+
+## 决策
+
+包内折算 `ui-conversation` 的 `chat/turn-metrics.ts` 是从 assistant 节点推导延迟/吞吐读数的唯一位置。`assistantStepReading` 把一个节点转成一次步骤读数：TTFT（首 token 延迟）需要 `stepStartTime` 与 `firstTokenTime` 同时存在，解码时长需要 `firstTokenTime`，负时长收敛为零，输出 token 数只在不可信的 `usage` 值有限且非负时才采纳。`deriveTurnMetrics` 按轮次折算读数：编号最小的步骤拥有该轮次的 TTFT 槽位，吞吐用「同时携带两者的那些步骤」的输出 token 总和除以解码时长总和，因此缺采样的步骤直接退出而不是让比值失真；两个数字都没有的轮次不产生条目。
+
+assistant 页脚把读数追加到既有 hover 显示的时间附属元素中、`用时` 之后，形如 `首 token {s}秒 · {tps} tok/s`，未记录的数字各自省略。ChatView 仅在该轮次的 `turnTimings` 条目带有 `endTime` 时才显示读数：已加载窗口是日志的连续后缀，因此窗口内已结算的轮次必然带着它的全部步骤，首步 TTFT 是真实值而非窗口截断的产物。`formatLatencySeconds` 不带单位，各语言模板各自拥有秒后缀（`TTFT {seconds}s`／`首 token {seconds}秒`）。
+
+统计行在其窗口折算中复用同一份步骤读数：`deriveStats` 累计 TTFT 总和／计数与解码时长／token 数，在 LLM／工具墙钟时间旁渲染经 `conversation` locale 命名空间本地化的延迟／吞吐分组（中文为 `首 token 平均 … · … tok/s`）。轮次计数、步骤计数、耗时、缓存与 token 各项的标签也使用同一命名空间。与那些墙钟时间一样，该分组是窗口作用域的，不折算任何计费；token 账目仍归 token-meter 投影。
+
+## 考虑过的替代方案
+
+**持久的会话投影（token-meter 形态）。** 在 host 侧用 `ProjectionDefinition` 折算步骤计时可以跨越压缩与窗口分页、覆盖整个日志。是暂缓而非否决：投影状态必须保持 O(1)（只能均值，不能分位数），它需要 host 改动加 schema，而聊天统计行的耗时事实本就被记录为窗口作用域——新分组沿用该作用域。后续 PR 可以在不挪动这些读数的情况下补上持久投影。
+
+**逐步骤页脚附属元素。** 让每条 assistant 消息显示自己的 TTFT，会给轮次中段的叙述节点挂上附属元素，而页脚设计刻意让它们保持无 chrome；trajectory 视图已经暴露逐步骤计时细节。
+
+**用节点是否在场而非 `turn/end` 计时做页脚门控。** 直接渲染碰巧加载到的步骤，会展示一个貌似合理、实为分页后「首个已加载步骤」的 TTFT。`endTime` 门控加上后缀窗口不变量，使显示的数字要么是该轮次真实的首步延迟，要么什么都不显示。
+
+## 后果
+
+窗口内已结算轮次的页脚在 hover 时于实际耗时之后显示 `首 token`／`tok/s`，统计行在墙钟时间旁以本地化标签显示窗口平均延迟与吞吐，全程不新增会话事件、不改 host。指标以省略的方式退化：没有计时或 usage 采样的提供方或步骤只是丢掉对应数字，而不会渲染成零。已加载窗口之外的更早历史仍不计入，已记录在包 README 的统计行限制中。
+
+两个读数都以实测墙钟时间作分母，因此都不可复现：同一个回放场景在本机连续两次跑出 69 与 70 tok/s，而一段 3 毫秒的回放流会读成 26333 tok/s。因此 Web aria golden 在既有的 `{{duration}}` 之外，把吞吐归一化为 `{{throughput}}`；页脚的装饰性分隔符也补上了两侧空格——没有它们，这些读数会连成一整串无障碍文本（`Ran for 13sTTFT 0.2s12 tok/s`），既让屏幕阅读器失去读数之间的边界，也让 `{{duration}}` 失去它赖以匹配的词边界。
@@ -0,0 +1,6 @@
+# Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
+# side as of the last confirmed-consistent state. Both languages carry equal authority;
+# after editing either side, bring the other along and re-record with:
+#   pnpm run verify-translation-pairing --write .agents/notes/implemented/feature/2026-08-05-composer-context-meter-breakdown.md
+2026-08-05-composer-context-meter-breakdown.md: a757bcbc8bc57f4c3a16f663a9c922155b8bb575
+2026-08-05-composer-context-meter-breakdown.zh.md: 441fd3013f2db721527838955b5ce227865615f1
@@ -0,0 +1,31 @@
+# Agent Note: Composer context meter with heuristic composition breakdown
+
+Status: implemented
+
+English | [中文](2026-08-05-composer-context-meter-breakdown.zh.md)
+
+## Problem
+
+The Web chat's stats line showed context occupancy as one inline figure (`Context N% of X`) among its billing groups. That answers "how full" but not "what fills it": nothing showed how the window divides between the system prompt, tool schemas, and conversation, and the one-line row has no room for that detail. The available numbers also live in two vocabularies — the provider-exact billed prompt size from `contextPressure` versus the token-meter's fixed character heuristic — and no existing surface could present composition without conflating them.
+
+## Decision
+
+Three cooperating pieces, one per package boundary:
+
+`dsh-session` exports the pure `deriveEventMessage(event)` (previously reachable only as a `Session` method, which now delegates to it) so a host-side fold can price surface nodes without a `Session` instance.
+
+`dsh-token-meter` extracts its pricing heuristic into `src/estimate.ts` and its positional surface fold into `src/surface-fold.ts` — both shared verbatim with the measurement service — and registers a third session projection, `contextBreakdown`, carrying `systemTokens` / `toolsTokens` / `messageTokens`. Envelope figures reprice last-wins on each `request/header` through `canonicalHeader`; the message figure replays `foldSurfaceTokens` over a per-node `{seq, tokens}` list, so it equals `measure().surfaceTokens` at every event boundary by construction and compaction shrinks it the way it shrinks the next request. The shared fold is total and allocation-fresh — it returns the next surface rather than mutating one — which keeps the service's validate-before-commit replay transaction intact: a throw leaves the replay cursor unmoved and the same malformed event fails identically on retry. A replace range absent from the folded surface throws: committed logs are surface-validated at append time, so an unresolvable range is log corruption, not a skippable event.
+
+`ui-conversation` moves context occupancy off the stats line (one home per fact) onto a composer-trailing `ContextMeter`: a 14px occupancy ring after the model seat fed by `contextPressure`, click-opening a panel that pairs the provider-exact percent and `~used / capacity` header with a 4px color-segmented bar and `~`-prefixed composition rows. The two vocabularies deliberately never reconcile — the heuristic shares only proportion the bar's colored segments and rows, each marked `~` because the fixed 4-chars-per-token heuristic systematically underprices CJK text and code. (The ring, header, and bar length were provider-exact as shipped here; they now read the provider-anchored `projectedTokens` instead, because the bare sample could not see a compaction — see [the meter's compaction blindness](../bug-fix/2026-08-05-context-meter-blind-to-compaction.md).) The header is one localized sentence (`context.aria`, shared with the ring's accessible name) split around its `{percent}` slot, so each locale owns the reading's position — English leads with it, Chinese trails it — while the reading keeps its own tone; a bar part whose width computes to zero is dropped rather than rendered, because `.segment`'s min-width would otherwise paint a filled sliver at 0% occupancy.
+
+## Alternatives considered
+
+**Deriving composition client-side from the loaded window.** The window is a contiguous log suffix: the `request/header` events carrying the system prompt and tool schemas may sit outside it, and paging would silently change the figures. Only a durable host-side projection survives paging and compaction, which is why the data crosses the wire as a third projection rather than a chat-window fold.
+
+**Scaling the heuristic rows to sum to `pressureTokens`.** Forced reconciliation fabricates precision: pressure lags one request, includes provider envelope overhead the estimator never models, and would make the rows move when nothing in the composition changed. Showing the estimator's real vocabulary with an explicit `~` was chosen instead.
+
+**Finer categories (rules, skills, MCP tools) as in Claude Code's `/context`.** Not separable here: the harness folds those contributions into the system text and the tools list before the request header exists, so three categories are the honest resolution.
+
+## Consequences
+
+Token-meter now registers three projection keys; unloading removes all three, and `contextBreakdown` restores from JSON checkpoints (`stateVersion` 1). The stats line dropped its Context group and the ring is the sole context UI. The panel's heuristic rows visibly disagree with the provider-exact header — accepted and signposted by the `~` prefix; improving estimate accuracy (for example CJK-aware weighting) is localized to `estimate.ts` and changes no seam. The legend's purple segment tint is a literal color because the design platform ships no purple static token.
@@ -0,0 +1,31 @@
+# Agent Note: composer 上下文占用圆环与启发式组成明细
+
+Status: implemented
+
+[English](2026-08-05-composer-context-meter-breakdown.md) | 中文
+
+## 问题
+
+Web 聊天的统计行把上下文占用率作为一个行内数字（`Context N% of X`）挤在计费分组之间。它回答了「有多满」，却回答不了「被什么占满」：没有任何地方展示窗口在系统提示词、工具 schema 与对话之间如何分配，而单行统计行也容纳不下这种明细。可用的数字还分属两套口径——来自 `contextPressure` 的提供方精确计费 prompt 规模，与 token-meter 的固定字符启发式——没有任何既有界面能在不混淆两者的前提下展示组成。
+
+## 决定
+
+三个协作部分，每个包边界一个：
+
+`dsh-session` 导出纯函数 `deriveEventMessage(event)`（此前只能通过 `Session` 方法访问，该方法现在委托给它），使 host 侧 fold 无需 `Session` 实例即可为表层节点计价。
+
+`dsh-token-meter` 把计价启发式抽取到 `src/estimate.ts`、把位置表层折叠抽取到 `src/surface-fold.ts`（两者都与测量服务逐字共享），并注册第三个会话投影 `contextBreakdown`，携带 `systemTokens` / `toolsTokens` / `messageTokens`。envelope 数字在每条 `request/header` 上经 `canonicalHeader` 按后者胜重新计价；消息数字在逐节点 `{seq, tokens}` 列表上重放 `foldSurfaceTokens`，因此它在每个事件边界上按构造等于 `measure().surfaceTokens`，压缩会像缩小下一个请求那样缩小它。这份共享折叠是全函数且总是新建数组——返回下一个表层而不是原地改写——从而保留了服务侧「先校验再提交」的重放事务：抛出时重放游标不前进，同一条畸形事件在重试时报同样的错。折叠表层中不存在的替换范围会直接抛出：已提交日志在追加时就经过表层校验，无法解析的范围是日志损坏，而不是可跳过的事件。
+
+`ui-conversation` 把上下文占用率从统计行移走（一个事实一个家），放到 composer 尾部的 `ContextMeter`：模型座位之后的一枚 14px 占用圆环，由 `contextPressure` 供数，点击弹出的面板把提供方精确的百分比与 `~已用 / 容量` 标题，与 4px 分色分段进度条及带 `~` 前缀的组成明细行并列。两套口径刻意永不对账——启发式占比只用于切分进度条的彩色分段与明细行，且每个启发式数字都标 `~`，因为固定的「4 字符≈1 token」启发式会系统性低估 CJK 文本与代码。（本记录落地时，圆环、标题与进度条总长取的是提供方精确值；它们现在改读锚定在提供方读数上的 `projectedTokens`，因为裸样本看不见压缩——见[仪表对压缩的失明](../bug-fix/2026-08-05-context-meter-blind-to-compaction.md)。）标题是一整句本地化文案（`context.aria`，与圆环的无障碍名共用），在 `{percent}` 槽位处切开渲染，于是读数的位置由各语言自己决定——英文在前、中文在后——同时读数保留自己的字重；宽度算出为零的分段直接不渲染，否则 `.segment` 的 min-width 会在 0% 占用时画出一段填充色。
+
+## 备选方案
+
+**在客户端从已加载窗口推导组成。** 窗口是日志的连续后缀：携带系统提示词与工具 schema 的 `request/header` 事件可能在窗口之外，翻页还会让数字悄悄变化。只有持久的 host 侧投影能在翻页与压缩后幸存，这正是数据以第三个投影而非聊天窗口 fold 的形式过线的原因。
+
+**把启发式明细行按比例缩放到与 `pressureTokens` 相加一致。** 强行对账是在捏造精度：压力滞后一个请求，还包含估算器从不建模的提供方封装开销，会让明细行在组成毫无变化时也跟着变动。最终选择以显式 `~` 展示估算器的真实口径。
+
+**更细的类别（rules、skills、MCP 工具，如 Claude Code 的 `/context`）。** 在这里不可分：harness 在请求标头存在之前就把这些贡献折入系统文本与工具列表，因此三个类别是诚实的分辨率。
+
+## 后果
+
+token-meter 现在注册三个投影键；卸载会移除全部三个，`contextBreakdown` 可从 JSON 检查点恢复（`stateVersion` 为 1）。统计行删除了 Context 分组，圆环成为唯一的上下文 UI。面板的启发式明细行与提供方精确的标题数字肉眼可见地不一致——已接受并以 `~` 前缀标示；提升估算精度（例如按 CJK 加权）只需改动 `estimate.ts`，不涉及任何 seam。图例的紫色分段色值是字面量，因为设计平台没有紫色静态 token。
@@ -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/proposed/architecture/2026-07-25-client-settings-locale-theme.md
-2026-07-25-client-settings-locale-theme.md: c86d6ac053f7bb87ce758613a5f3a0a34951e428
-2026-07-25-client-settings-locale-theme.zh.md: 379c6d0afee71b51dd15605fcac5689fb53ee8a3
+2026-07-25-client-settings-locale-theme.md: fdcdcff92fa324803d5f2343f3fc3d9dcca069c7
+2026-07-25-client-settings-locale-theme.zh.md: b1536a1515fa7022320934dfdabf94c815e8ba04
@@ -55,11 +55,11 @@ root
            └─ models (order 10)         ui-models 注册
 ```

-Section and item contributions both use declaration-aware deferral (ui-slots' `deferRegistration()`: ledger-judged presence, one-call disposal; localized labels ride the label thunk from the [full-rollout note](../../implemented/architecture/2026-07-30-client-locale-full-rollout.md), not `refresh()`) and do not depend on the client manifest's apply order. The SlotMap types split homes: trigger/header/close/section have their canonical home in the ui-settings contract (the consumers, general and models, both depend on the shell — no cycle); `settings.general.item`'s canonical home is the locale package — it is the lowest common dependency of all item registrants (a settings row always carries copy), while the declarer general's contract is unreachable from locale/ui-theme (it would form a cycle); ui-theme consumes it through a re-export seam.
+Section and item contributions use `ctx.slots.inject()` and do not depend on the client manifest's apply order; localized labels ride the label thunk from the [full-rollout note](../../implemented/architecture/2026-07-30-client-locale-full-rollout.md). The SlotMap types split homes: trigger/header/close/section have their canonical home in the ui-settings contract (the consumers, general and models, both depend on the shell — no cycle); `settings.general.item`'s canonical home is the locale package — it is the lowest common dependency of all item registrants (a settings row always carries copy), while the declarer general's contract is unreachable from locale/ui-theme (it would form a cycle); ui-theme consumes it through a re-export seam.

-### Future work: promote slot declarations to first-class injectable waits
+### Slot declarations are first-class injectable waits

-`deferRegistration()` is behaviorally isomorphic to `ctx.inject` — one waits on a ledger declaration, the other on service presence, with matching disappear/reappear lifecycle semantics; the difference is that the fiber form's disposer lifetime naturally equals the declaration's lifetime, so the stale-disposer presence-judging machinery disappears entirely. Direction (a separate PR): SlotsService bridges each slot into a `slot:<name>` service (value = the slot spec) at declaration commit / cascade removal, registrants migrate from `deferRegistration()` to a nested `ctx.inject(['slot:<name>'], cb)`, then `deferRegistration()` is deleted and packages/client/AGENTS.md checklist item 4 is rewritten. Boundaries to pin down: the nested fiber's harmless wait must not be named by the boot fail-loud scan (needs a test); the `slot:` namespace and the silent-wait-on-typo stance; provide keys are flat names (`slot:a.b` is one key, not a property path on `ctx.slots`). This phase keeps the `deferRegistration()` function form.
+`SlotsService.inject()` now waits on the typed ledger key directly; it does not bridge declarations into synthetic `slot:<name>` Cordis services. The callback follows declaration collapse and redeclaration while its controller remains owned by the contributing plugin fiber, and direct registration into an undeclared slot still fails loud. This removes the stale-disposer presence machine and the typo-prone parallel service namespace. The complete lifecycle and failure contract lives in the [slot declaration injection decision](../../implemented/architecture/2026-08-05-slot-declaration-injection.md).

 ### Service contracts

@@ -127,4 +127,4 @@ Locale ships with 中文 and English built in; `setLocale`/`setTheme` are the on

 ## Risks

-The apply order of slot declarations and contributions is not fixed, so every section/item registrant must keep declaration-aware registration and judge presence by the ledger, not by a local disposer. Service events may fire before a row's first render, so both a feature row store's init and the inject attach must align to the current snapshot from the getter. The duplicated merge copies of `settings.general.item` (locale, ui-theme) must stay verbatim-identical to the ui-settings canonical home — any drift means changing all three together. Layout must clean up the global attributes it set on unmount, and ThemeService must remove its matchMedia listener on dispose, so nothing lingers after HMR.
+The apply order of slot declarations and contributions is not fixed, so every section/item registrant must use `ctx.slots.inject()` rather than a service or local-disposer presence signal. Service events may fire before a row's first render, so both a feature row store's init and the inject attach must align to the current snapshot from the getter. The duplicated merge copies of `settings.general.item` (locale, ui-theme) must stay verbatim-identical to the ui-settings canonical home — any drift means changing all three together. Layout must clean up the global attributes it set on unmount, and ThemeService must remove its matchMedia listener on dispose, so nothing lingers after HMR.
@@ -55,11 +55,11 @@ root
            └─ models (order 10)         ui-models 注册
 ```

-section/item contribution 均使用 declaration-aware deferral（ui-slots 的 `deferRegistration()`：ledger 判在位、一键 dispose（资源释放）；本地化 label 走 [全量接入 Note](../../implemented/architecture/2026-07-30-client-locale-full-rollout.md) 的 label thunk，不再 `refresh()`），不依赖 client manifest（元数据清单）的 apply 顺序。SlotMap 类型分家：trigger/header/close/section 正家在 ui-settings 契约（消费方 general/models 均依赖壳，无环）；`settings.general.item` 正家在 locale 包——它是全部 item 注册方的最低公共依赖（设置行必带文案），而声明方 general 的契约对 locale/ui-theme 不可达（会成环）；ui-theme 经 re-export seam 消费。
+section/item contribution 使用 `ctx.slots.inject()`，不依赖 client manifest 的 apply 顺序；本地化 label 走 [全量接入 Note](../../implemented/architecture/2026-07-30-client-locale-full-rollout.md) 的 label thunk。SlotMap 类型分家：trigger/header/close/section 正家在 ui-settings contract（消费者 general/models 均依赖壳，无环）；`settings.general.item` 正家在 locale 包——它是全部 item 注册方的最低公共依赖（设置行必带文案），而声明方 general 的 contract 对 locale/ui-theme 不可达（会成环）；ui-theme 经 re-export seam 消费。

-### 未来工作：slot 声明升格为可 inject 的一等等待物
+### slot 声明是一等可注入等待对象

-`deferRegistration()` 与 `ctx.inject` 行为同构——一个等 ledger 声明、一个等服务在场，消失/重现的生命周期语义一致；差别只在 fiber 版的 disposer 生命周期天然等于声明生命周期，陈旧 disposer 判在位机器可整体消失。方向（另开 PR）：SlotsService 在声明落账/级联拆除处把每个 slot 桥接成 `slot:<name>` 服务（value 为 slot spec），注册方从 `deferRegistration()` 迁为嵌套 `ctx.inject(['slot:<name>'], cb)`，随后删除 `deferRegistration()` 并改写 packages/client/AGENTS.md checklist 第 4 条。待钉死的边界：嵌套 fiber 的无害等待不被 boot fail-loud 扫描点名（需测试）；`slot:` 名字空间与 typo 静默等待的口径；provide 键是平面名（`slot:a.b` 是一个键，不是 `ctx.slots` 的属性路径）。本期维持 `deferRegistration()` 函数形式。
+`SlotsService.inject()` 直接等待有类型约束的 ledger key；它不会将声明桥接为合成的 `slot:<name>` Cordis 服务。回调会跟随声明折叠与重新声明，而其控制器仍归贡献方插件 fiber 所有；直接向未声明 slot 注册仍会大声失败。这删除了陈旧 disposer 判在位机器和容易因拼写错误出错的平行服务命名空间。完整的生命周期与失败契约见 [slot 声明注入决策](../../implemented/architecture/2026-08-05-slot-declaration-injection.md)。

 ### 服务契约

@@ -127,4 +127,4 @@ Locale 内置中文和 English；`setLocale`/`setTheme` 是唯一写入口，未

 ## 风险

-slot 声明与 contribution 的 apply 顺序不固定，所有 section/item 注册方必须保留 declaration-aware registration，并以 ledger（而非本地 disposer）判定在位。服务事件可能早于行首次渲染，功能行 store 的 init 与 inject attach 都必须从 getter 对齐当前 snapshot。`settings.general.item` 的重复合并副本（locale、ui-theme）与 ui-settings 正家必须逐字一致，漂移即三处一起改。Layout 卸载时必须清理自己设置的全局属性，ThemeService dispose 时必须移除 matchMedia 监听，避免 HMR（热模块替换）后残留。
+slot 声明与 contribution 的 apply 顺序不固定，所有 section/item 注册方必须使用 `ctx.slots.inject()`，而不能以服务或本地 disposer 作为在位信号。service event 可能早于行首次渲染，功能行 store 的 init 与 inject attach 都必须从 getter 对齐当前 snapshot。`settings.general.item` 的重复合并副本（locale、ui-theme）与 ui-settings 正家必须逐字一致，漂移即三处一起改。Layout 卸载时必须清理自己设置的全局属性，ThemeService dispose 时必须移除 matchMedia 监听，避免 HMR 后残留。
@@ -121,6 +121,21 @@ it('boots the built plugin graph and renders a fixture session end to end', asyn
    expect(document.querySelector('[data-sample="bash"]')).not.toBeNull()
  }, { timeout: 10_000 })

+  // Resolve the resident approval so the ordinary composer bar (which owns
+  // ContextMeter) resumes without replacing the session shell. This minimal
+  // boot graph intentionally does not mount the separate question UI plugin.
+  fireEvent.click(await screen.findByRole('button', { name: 'Allow once' }))
+
+  // The fixture mirrors all three token-meter projections, so the assembled
+  // ContextMeter reaches its composition panel instead of only the occupancy
+  // fallback path.
+  const contextTrigger = await screen.findByRole('button', { name: /of context used/ })
+  fireEvent.click(contextTrigger)
+  const contextPanel = await screen.findByRole('dialog', { name: 'of context used' })
+  within(contextPanel).getByText('System prompt')
+  within(contextPanel).getByText('Tools')
+  within(contextPanel).getByText('Messages')
+
  // The write/edit turns render a real diff card through the assembled graph
  // (the keyed FileMutationRow composing ToolRow + DiffBlock), not just the
  // fixture's raw text. The card is collapsed by default, so expand each edit/
@@ -26,6 +26,7 @@ const DONE = 'MATH_RENDERING_DONE'
 /** Build a settled assistant reply that exercises every supported math delimiter. */
 function mathFixture(): string {
  const session = Session.create(SessionId('math-rendering-source'))
+  const eventTimeOrigin = new Date().setHours(12, 0, 0, 0)
  session.append('turn/start', {
    turn: 1,
  })
@@ -76,7 +77,10 @@ function mathFixture(): string {
      createdAt: 0,
      cwd: '{{cwd}}',
    }),
-    ...session.events.map(event => JSON.stringify(event)),
+    ...session.events.map(event => JSON.stringify({
+      ...event,
+      time: eventTimeOrigin + event.seq * 1_000,
+    })),
    '',
  ].join('\n')
 }
@@ -476,15 +476,29 @@ export function fixtureUserPrompts(fixtureText: string): string[] {
 * @param id - the seeded session id (stable for deterministic goldens).
 * @returns the seeded id.
 */
-export async function seedSession(scaffold: WebScaffold, fixtureText: string, id: string): Promise<SessionId> {
+/**
+ * Realize a recorded seed fixture against one scaffold: substitute the
+ * `{{sessionId}}`/`{{cwd}}` placeholders and rewrite the recorded cwd to the
+ * scaffold's workspace. Idempotent, so a caller may realize early (e.g. to
+ * price content exactly as the host will fold it) and still pass the result
+ * through {@link seedSession}.
+ * @param scaffold - the booted scaffold whose workspace the seed targets.
+ * @param fixtureText - the committed seed fixture text.
+ * @param id - the session id the seed is realized for.
+ * @returns the realized fixture text.
+ */
+export function realizeSeedFixture(scaffold: WebScaffold, fixtureText: string, id: string): string {
  const realized = fixtureText
    .split('{{sessionId}}').join(id)
    .split('{{cwd}}').join(scaffold.workspaceCwd)
  const fixtureCwd = (JSON.parse(realized.split('\n', 1)[0]!) as { cwd?: string }).cwd
-  const rewritten = fixtureCwd === undefined
+  return fixtureCwd === undefined
    ? realized
    : realized.split(fixtureCwd).join(scaffold.workspaceCwd)
-  const events = parseSessionLog(rewritten)
+}
+
+export async function seedSession(scaffold: WebScaffold, fixtureText: string, id: string): Promise<SessionId> {
+  const events = parseSessionLog(realizeSeedFixture(scaffold, fixtureText, id))
  if (events.length === 0) throw new Error('seed fixture has no events')
  const last = events[events.length - 1]!
  // An open final turn would be mutated by resume's crash repair on first
@@ -518,8 +532,14 @@ export async function seedSession(scaffold: WebScaffold, fixtureText: string, id
 }

 /**
- * Normalize an aria snapshot: uuid, cwd, workspace-basename, and duration
- * volatility collapse to stable tokens.
+ * Normalize an aria snapshot: uuid, cwd, workspace-basename, duration, and
+ * decode-throughput volatility collapse to stable tokens.
+ *
+ * Throughput needs a token for the same reason durations do, and no fixture
+ * can supply one: the figure divides a replayed step's output tokens by the
+ * wall time the local run took to stream them, so it moves between two runs
+ * on one machine (measured 69 → 70 tok/s) and swings wildly on a fast replay
+ * (26333 tok/s for a 3 ms stream).
 */
 function normalizeAria(snapshot: string, workspaceCwd: string): string {
  // The session heading renders the workspace's basename, not the full
@@ -529,14 +549,17 @@ function normalizeAria(snapshot: string, workspaceCwd: string): string {
    .split(workspaceCwd).join('{{cwd}}')
    .split(base).join('{{workspace}}')
    .replace(/[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}/gi, '{{uuid}}')
+    // The optional space in `\d+m ?\d+s` covers both minute spellings: the
+    // stats line's compact `2m42s` and the message-chrome template's `2m 42s`.
    .replace(
-      /~\d+(?:y(?: \d+mo)?|mo(?: \d+d)?)|\b(?:\d+d(?: \d+h(?: \d+m \d+s)?)?|\d+h \d+m \d+s|\d+m \d+s|\d+(?:\.\d+)?s|\d+(?:\.\d+)?ms)\b/g,
+      /~\d+(?:y(?: \d+mo)?|mo(?: \d+d)?)|\b(?:\d+d(?: \d+h(?: \d+m \d+s)?)?|\d+h \d+m \d+s|\d+m ?\d+s|\d+(?:\.\d+)?s|\d+(?:\.\d+)?ms)\b/g,
      duration => duration.startsWith('~') ? duration : '{{duration}}',
    )
    .replace(
      /约\d+(?:年(?:\d+个月)?|个月(?:\d+天)?)|\d+(?:天(?:\d+小时(?:\d+分\d+秒)?)?|小时\d+分\d+秒|分\d+秒|(?:\.\d+)?秒)/g,
      duration => duration.startsWith('约') ? duration : '{{duration}}',
    )
+    .replace(/\d+(?:\.\d+)?(?= tok\/s(?!\w))/g, '{{throughput}}')
    // Message IconActions clocks widen by calendar day/year; collapse every
    // shape so goldens stay stable across midnight and year boundaries.
    .replace(/\d{4}年\d{1,2}月\d{1,2}日 \d{2}:\d{2}/g, '{{clock}}')
@@ -16,11 +16,14 @@ import type { Browser, Page } from 'playwright'
 import { chromium } from 'playwright'
 import { afterAll, beforeAll, describe, expect, it, onTestFailed } from 'vitest'
 import { createUserMessage } from '@deepseek-ai/dsh-llm'
-import { SessionId } from '@deepseek-ai/dsh-session'
+import type { ContentBlock, Message } from '@deepseek-ai/dsh-llm'
+import { deriveEventMessage, SessionId } from '@deepseek-ai/dsh-session'
+import type { SessionEvent } from '@deepseek-ai/dsh-session'
+import type { TokenMeterService } from '@deepseek-ai/dsh-token-meter'
 import { join } from 'node:path'
 import {
  assertFixtureInventory, captureStableAria, compareOrRefreshGolden, fixtureUserPrompts,
-  launchWebScaffold, recordFixture, seedSession, watchConsole, webSnapshotMode, type WebScaffold,
+  launchWebScaffold, realizeSeedFixture, recordFixture, seedSession, watchConsole, webSnapshotMode, type WebScaffold,
 } from './scaffold.ts'
 import { newEnglishPage, saveFailureShot } from './support.ts'

@@ -41,17 +44,22 @@ const PROMPT = 'Use the read tool twice in one assistant message: read a.txt and
 * 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.
+ * @param raw - the seed fixture text, already realized (placeholder-free) so
+ * the shadow price below is computed from the exact strings the host folds.
+ * @param meter - the composed token meter; the appended `compact/summary`'s
+ * shadow price must be the exact heuristic price of the shadowed nodes, the
+ * way compact-basic derives it, because the token-meter projections subtract
+ * it verbatim.
 * @returns the fixture with a compacted turn appended.
 */
-function withCompaction(raw: string): string {
+function withCompaction(raw: string, meter: TokenMeterService): 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
-    data?: { turn?: unknown }
+    data?: { turn?: unknown; message?: unknown; content?: unknown; callId?: unknown; isError?: unknown }
  })
  const surfaceSeqs = events
    .filter(event => event.surfaceOp === 'append'
@@ -87,6 +95,31 @@ function withCompaction(raw: string): string {
  }
  at({ type: 'turn/start', data: { turn } })
  const startSeq = at({ type: 'compact/start', data: { turn } })
+  // Load-bearing exactness: the projections subtract this count verbatim, so
+  // it must equal what the host's fold prices for these nodes. The estimator
+  // prices message CONTENT only, so a minimal wrapper per storage shape is
+  // exact — pre-identity rows carry bare `content` (the persistence read path
+  // upgrades them), a current row carries the full `message` envelope.
+  const priceRow = (row: (typeof events)[number]): number => {
+    if (row.data?.message !== undefined) {
+      const message = deriveEventMessage(row as unknown as SessionEvent)
+      return message === null ? 0 : meter.estimateMessage(message)
+    }
+    const content = row.data?.content as ContentBlock[]
+    if (row.type === 'tool/result') {
+      return meter.estimateMessage({
+        content: [{ type: 'tool-result', toolCallId: row.data?.callId, content, isError: row.data?.isError === true }],
+      } as unknown as Message)
+    }
+    // An empty-content assistant message derives no transcript entry.
+    if (row.type === 'assistant/message' && content.length === 0) return 0
+    return meter.estimateMessage({ content } as unknown as Message)
+  }
+  const shadowedTokenCount = surfaceSeqs.reduce((total, surfaceSeq) => {
+    const event = events.find(candidate => candidate.seq === surfaceSeq)
+    if (event === undefined) throw new Error(`seeded-history compaction: shadowed seq ${surfaceSeq} is not in the seed`)
+    return total + priceRow(event)
+  }, 0)
  const summarySeq = at({
    type: 'compact/summary',
    data: {
@@ -96,7 +129,7 @@ function withCompaction(raw: string): string {
      }],
      shadowedRange: { start: first, end: last },
      shadowedSeqs: surfaceSeqs,
-      shadowedTokenCount: 10_000,
+      shadowedTokenCount,
      provider: 'snapshot',
      model: 'snapshot-compactor',
    },
@@ -137,7 +170,10 @@ 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, withCompaction(raw), SEED_ID)
+      const meter = scaffold.ctx.get('tokenMeter')
+      if (meter === undefined) throw new Error('seeded-history requires the composed token meter')
+      const realized = realizeSeedFixture(scaffold, raw, SEED_ID)
+      await seedSession(scaffold, withCompaction(realized, meter), SEED_ID)
    }
    browser = await chromium.launch()
    page = await newEnglishPage(browser)
@@ -30,4 +30,4 @@
  - text: Select model
  - img
 - button "Send message" [disabled]
- text: 1 turns · 1 steps Tool call {{duration}} Cache hit 0% Input 10 tok · Output 10 tok
+- text: 1 turns · 1 steps LLM {{duration}} · Tool call {{duration}} TTFT avg {{duration}} · {{throughput}} tok/s Cache hit 0% Input 10 tok · Output 10 tok
@@ -36,7 +36,7 @@
  - img
 - button "Branch into a new conversation":
  - img
- text: {{clock}}Ran for {{duration}}
+- text: {{clock}} Ran for {{duration}} TTFT {{duration}} {{throughput}} tok/s
 - textbox "Message the agent"
 - button "Commands":
  - img
@@ -44,5 +44,6 @@
 - button "Select model, current DeepSeek-V4-Flash":
  - text: DeepSeek-V4-Flash
  - img
+- button "7% of context used"
 - button "Send message" [disabled]
- text: 1 turns · 2 steps Tool call {{duration}} Context 7% of 128K Cache hit 52% Input 17.2K tok · Output 252 tok
+- text: 1 turns · 2 steps LLM {{duration}} · Tool call {{duration}} TTFT avg {{duration}} · {{throughput}} tok/s Cache hit 52% Input 17.2K tok · Output 252 tok
@@ -51,7 +51,7 @@
  - img
 - button "Branch into a new conversation":
  - img
- text: {{clock}}Ran for {{duration}}
+- text: {{clock}} Ran for {{duration}} TTFT {{duration}} {{throughput}} tok/s
 - textbox "Message the agent"
 - button "Commands":
  - img
@@ -59,5 +59,6 @@
 - button "Select model, current DeepSeek-V4-Flash":
  - text: DeepSeek-V4-Flash
  - img
+- button "13% of context used"
 - button "Send message" [disabled]
- text: 1 turns · 4 steps Tool call {{duration}} Context 13% of 128K Cache hit 77% Input 66.5K tok · Output 312 tok
+- text: 1 turns · 4 steps LLM {{duration}} · Tool call {{duration}} TTFT avg {{duration}} · {{throughput}} tok/s Cache hit 77% Input 66.5K tok · Output 312 tok
@@ -31,7 +31,7 @@
  - img
 - button "Branch into a new conversation":
  - img
- text: {{clock}}Ran for {{duration}}
+- text: {{clock}} Ran for {{duration}} TTFT {{duration}} {{throughput}} tok/s
 - textbox "Message the agent"
 - button "Commands":
  - img
@@ -39,5 +39,6 @@
 - button "Select model, current DeepSeek-V4-Flash":
  - text: DeepSeek-V4-Flash
  - img
+- button "6% of context used"
 - button "Send message" [disabled]
- text: 1 turns · 2 steps Tool call {{duration}} Context 6% of 128K Cache hit 99% Input 15.7K tok · Output 111 tok
+- text: 1 turns · 2 steps LLM {{duration}} · Tool call {{duration}} TTFT avg {{duration}} · {{throughput}} tok/s Cache hit 99% Input 15.7K tok · Output 111 tok
@@ -23,7 +23,7 @@
  - img
 - button "Branch into a new conversation":
  - img
- text: {{clock}}Ran for {{duration}}
+- text: {{clock}} Ran for {{duration}} TTFT {{duration}} {{throughput}} tok/s
 - textbox "Message the agent"
 - button "Commands":
  - img
@@ -31,5 +31,6 @@
 - button "Select model, current DeepSeek-V4-Flash":
  - text: DeepSeek-V4-Flash
  - img
+- button "6% of context used"
 - button "Send message" [disabled]
- text: 1 turns · 1 steps Context 6% of 128K Cache hit 99% Input 7.8K tok · Output 21 tok
+- text: 1 turns · 1 steps LLM {{duration}} TTFT avg {{duration}} · {{throughput}} tok/s Cache hit 99% Input 7.8K tok · Output 21 tok
@@ -20,7 +20,7 @@
  - img
 - button "Branch into a new conversation":
  - img
- text: {{clock}}Ran for {{duration}}
+- text: {{clock}} Ran for {{duration}}
 - textbox "Message the agent"
 - button "Commands":
  - img
@@ -25,7 +25,7 @@
  - img
 - button "Branch into a new conversation":
  - img
- text: {{clock}}Ran for {{duration}}
+- text: {{clock}} Ran for {{duration}} TTFT {{duration}} {{throughput}} tok/s
 - textbox "Message the agent"
 - button "Commands":
  - img
@@ -33,5 +33,6 @@
 - button "Select model, current DeepSeek-V4-Flash":
  - text: DeepSeek-V4-Flash
  - img
+- button "6% of context used"
 - button "Send message" [disabled]
- text: 1 turns · 1 steps Context 6% of 128K Cache hit 99% Input 7.8K tok · Output 79 tok
+- text: 1 turns · 1 steps LLM {{duration}} TTFT avg {{duration}} · {{throughput}} tok/s Cache hit 99% Input 7.8K tok · Output 79 tok
@@ -19,7 +19,7 @@
  - img
 - button "Branch into a new conversation":
  - img
- text: {{clock}}Ran for {{duration}}
+- text: {{clock}} Ran for {{duration}}
 - textbox "Message the agent"
 - button "Commands":
  - img
@@ -35,7 +35,7 @@
  - img
 - button "Branch into a new conversation":
  - img
- text: {{clock}}Ran for {{duration}}
+- text: {{clock}} Ran for {{duration}}
 - textbox "Message the agent"
 - button "Commands":
  - img
@@ -44,4 +44,4 @@
  - text: Select model
  - img
 - button "Send message" [disabled]
- text: 1 turns · 1 steps Input 0 tok · Output 0 tok
+- text: 1 turns · 1 steps LLM {{duration}} Input 0 tok · Output 0 tok
@@ -20,7 +20,7 @@
  - img
 - button "Branch into a new conversation" [disabled]:
  - img
- text: Available only on the last message of a completed turn 7/25 {{clock}}Ran for {{duration}}
+- text: Available only on the last message of a completed turn 7/25 {{clock}} Ran for {{duration}} TTFT {{duration}} {{throughput}} tok/s
 - button "Read a.txt":
  - img
  - img
@@ -46,7 +46,7 @@
  - img
 - button "Branch into a new conversation":
  - img
- text: 7/25 {{clock}}Ran for {{duration}}
+- text: 7/25 {{clock}} Ran for {{duration}}
 - textbox "Message the agent"
 - button "Commands":
  - img
@@ -55,4 +55,4 @@
  - text: Select model
  - img
 - button "Send message" [disabled]
- text: 2 turns · 3 steps Tool call {{duration}} Cache hit 98% Input 7.8K tok · Output 103 tok
+- text: 2 turns · 3 steps LLM {{duration}} · Tool call {{duration}} TTFT avg {{duration}} · {{throughput}} tok/s Cache hit 98% Input 7.8K tok · Output 103 tok
@@ -36,7 +36,7 @@
  - img
 - button "Branch into a new conversation":
  - img
- text: {{clock}}Ran for {{duration}}
+- text: {{clock}} Ran for {{duration}} TTFT {{duration}} {{throughput}} tok/s
 - textbox "Message the agent"
 - button "Commands":
  - img
@@ -44,5 +44,6 @@
 - button "Select model, current DeepSeek-V4-Flash":
  - text: DeepSeek-V4-Flash
  - img
+- button "4% of context used"
 - button "Send message" [disabled]
- text: 1 turns · 2 steps Tool call {{duration}} Context 4% of 128K Cache hit 51% Input 10.2K tok · Output 346 tok
+- text: 1 turns · 2 steps LLM {{duration}} · Tool call {{duration}} TTFT avg {{duration}} · {{throughput}} tok/s Cache hit 51% Input 10.2K tok · Output 346 tok
@@ -31,7 +31,7 @@
  - img
 - button "Branch into a new conversation":
  - img
- text: {{clock}}Ran for {{duration}}
+- text: {{clock}} Ran for {{duration}} TTFT {{duration}} {{throughput}} tok/s
 - textbox "Message the agent"
 - button "Commands":
  - img
@@ -39,5 +39,6 @@
 - button "Select model, current DeepSeek-V4-Flash":
  - text: DeepSeek-V4-Flash
  - img
+- button "3% of context used"
 - button "Send message" [disabled]
- text: 1 turns · 2 steps Tool call {{duration}} Context 3% of 128K Cache hit 95% Input 8.6K tok · Output 180 tok
+- text: 1 turns · 2 steps LLM {{duration}} · Tool call {{duration}} TTFT avg {{duration}} · {{throughput}} tok/s Cache hit 95% Input 8.6K tok · Output 180 tok
@@ -20,7 +20,7 @@
  - img
 - button "Branch into a new conversation":
  - img
- text: {{clock}}Ran for {{duration}}
+- text: {{clock}} Ran for {{duration}}
 - button "2 queued messages" [expanded]
 - list:
  - listitem:
@@ -7,7 +7,7 @@ line=138: export function SearchBlock(props: SearchBlockProps) {
 line=141:   const [collapsed, setCollapsed] = useState<ReadonlySet<number>>(() => new Set())
 line=35:   const search = searchCardModel(block)
 line=52:       search={search}
-line=73:     ctx.slots.register({ name: 'conversation.chat.toolview', key: 'grep', locale: NS }, SearchRow)
+line=78:       yield ctx.slots.register({ name: 'conversation.chat.toolview', key: 'grep', locale: NS }, SearchRow)
 expand=… 其余 4 行
 recovery=Found 9 of 42 matches

@@ -22,6 +22,6 @@ packages/client/ui-conversation/src/client/toolviews/search-row.tsx
 Line 33: export function SearchRow({ toolName, block, inspect, t }: SearchRowProps) {
 Line 35:   const search = searchCardModel(block)
 Line 52:       search={search}
-Line 73:     ctx.slots.register({ name: 'conversation.chat.toolview', key: 'grep', locale: NS }, SearchRow)
+Line 78:       yield ctx.slots.register({ name: 'conversation.chat.toolview', key: 'grep', locale: NS }, SearchRow)

 (Full grep result stored at: fixture://spill/grep-66. Read it to see every match.)
@@ -33,7 +33,7 @@
  - img
 - button "Branch into a new conversation":
  - img
- text: 7/25 {{clock}}Ran for {{duration}}
+- text: 7/25 {{clock}} Ran for {{duration}} TTFT {{duration}} {{throughput}} tok/s
 - button "Context compacted View compaction summary":
  - img
  - text: Context compacted View compaction summary
@@ -51,4 +51,4 @@
  - text: Select model
  - img
 - button "Send message" [disabled]
- text: 1 turns · 2 steps Tool call {{duration}} Cache hit 98% Input 15.8K tok · Output 135 tok
+- text: 1 turns · 2 steps LLM {{duration}} · Tool call {{duration}} TTFT avg {{duration}} · {{throughput}} tok/s Cache hit 98% Input 15.8K tok · Output 135 tok
@@ -33,7 +33,7 @@
  - img
 - button "Branch into a new conversation":
  - img
- text: 7/25 {{clock}}Ran for {{duration}}
+- text: 7/25 {{clock}} Ran for {{duration}} TTFT {{duration}} {{throughput}} tok/s
 - button "Context compacted View compaction summary":
  - img
  - text: Context compacted View compaction summary
@@ -49,4 +49,4 @@
  - text: Select model
  - img
 - button "Send message" [disabled]
- text: 1 turns · 2 steps Tool call {{duration}} Cache hit 98% Input 15.8K tok · Output 135 tok
+- text: 1 turns · 2 steps LLM {{duration}} · Tool call {{duration}} TTFT avg {{duration}} · {{throughput}} tok/s Cache hit 98% Input 15.8K tok · Output 135 tok
@@ -37,7 +37,7 @@
  - img
 - button "Branch into a new conversation":
  - img
- text: {{clock}}Ran for {{duration}}
+- text: {{clock}} Ran for {{duration}} TTFT {{duration}} {{throughput}} tok/s
 - textbox "Message the agent"
 - button "Commands":
  - img
@@ -45,5 +45,6 @@
 - button "Select model, current DeepSeek-V4-Flash":
  - text: DeepSeek-V4-Flash
  - img
+- button "6% of context used"
 - button "Send message" [disabled]
- text: 1 turns · 2 steps Tool call {{duration}} Context 6% of 128K Cache hit 98% Input 15.8K tok · Output 156 tok
+- text: 1 turns · 2 steps LLM {{duration}} · Tool call {{duration}} TTFT avg {{duration}} · {{throughput}} tok/s Cache hit 98% Input 15.8K tok · Output 156 tok
@@ -28,7 +28,7 @@
  - img
 - button "Branch into a new conversation":
  - img
- text: {{clock}}Ran for {{duration}} Now give the same explanation to a human reader. {{clock}}
+- text: {{clock}} Ran for {{duration}} TTFT {{duration}} {{throughput}} tok/s Now give the same explanation to a human reader. {{clock}}
 - button "Copy":
  - img
 - button "Branch into a new conversation" [disabled]:
@@ -43,10 +43,11 @@
  - img
 - button "Branch into a new conversation":
  - img
- text: {{clock}}Ran for {{duration}}
+- text: {{clock}} Ran for {{duration}} TTFT {{duration}} {{throughput}} tok/s
 - textbox "Message the agent"
 - button "Commands":
  - img
 - 'button "Access mode, current: Workspace Write"': Workspace Write
+- button "6% of context used"
 - button "Send message" [disabled]
- text: 2 turns · 2 steps Context 6% of 128K Cache hit 99% Input 15.6K tok · Output 158 tok
+- text: 2 turns · 2 steps LLM {{duration}} TTFT avg {{duration}} · {{throughput}} tok/s Cache hit 99% Input 15.6K tok · Output 158 tok
@@ -23,7 +23,7 @@
  - img
 - button "Branch into a new conversation":
  - img
- text: {{clock}}Ran for {{duration}}
+- text: {{clock}} Ran for {{duration}} TTFT {{duration}} {{throughput}} tok/s
 - textbox "Message the agent"
 - button "Commands":
  - img
@@ -31,5 +31,6 @@
 - button "Select model, current DeepSeek-V4-Flash":
  - text: DeepSeek-V4-Flash
  - img
+- button "0% of context used"
 - button "Send message" [disabled]
- text: 1 turns · 2 steps Tool call {{duration}} Context 0% of 128K Cache hit 0% Input 22 tok · Output 7 tok
+- text: 1 turns · 2 steps LLM {{duration}} · Tool call {{duration}} TTFT avg {{duration}} · {{throughput}} tok/s Cache hit 0% Input 22 tok · Output 7 tok
@@ -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 docs/architecture.md
-architecture.md: 729a654c1379b9afab213b9bf604d5db17d01768
-architecture.zh.md: 8dc128651f01b0a64fd8c8f2148aa4644dc50399
+architecture.md: 9b84c1482cb379fd796e21db45f128ba49750c54
+architecture.zh.md: 84708fcae24623e50b0157782cf459c35a55844b
@@ -66,15 +66,15 @@ Waterfalls are around-middleware: listeners delegate with `next()`; returning wi

 ## Default Loop Lifecycle

-A **session** is append-only. A **turn** claims one queued follow-up, waits for its predecessor's checkpoint, and may share its `running` interval ([decision](../.agents/notes/implemented/simplification/2026-07-17-one-send-one-turn.md)); injection claims none. A **step** is one model request plus tools. Quotes in the [sequence](agent-lifecycle.md) mark durable events.
+A **session** is append-only. A **turn** claims one queued follow-up, waits for its predecessor's checkpoint, and may share its `running` interval ([decision](../.agents/notes/implemented/simplification/2026-07-17-one-send-one-turn.md)); injection claims none. A **step** is one model request plus tools. Fresh creation and persisted resume first acquire an exact unpublished `SessionPreparation`; Agent and session publication happen only after private setup against that Session is ready ([decision](../.agents/notes/implemented/architecture/2026-08-05-session-preparation.md)). Quotes in the [sequence](agent-lifecycle.md) mark durable events.

 Creation without an id mints `<config-id>-session-<uuid>`; `sessionId` resumes or creates, while `resumeSessionId` requires history. Resume restores lineage and delegation depth before publication; setup failure emits `agent-loop/config-start-failed`.

 ### Turn Flow

 ```text
-choose declarative identity and fresh/resume path
-  -> prepare private session + agent.ctx -> await unpublished setup
+choose declarative identity and acquire fresh/restored SessionPreparation
+  -> prepare private agent.ctx around exact Session -> await unpublished setup -> invoke optional synchronous setup commit
  -> enter session + agent -> session/created -> agent/created
  -> enable driving -> agent/session-start(source) -> start driver
 forever:
@@ -66,15 +66,15 @@ waterfall（瀑布式事件）是环绕中间件：监听器通过 `next()` 委

 ## 默认循环生命周期

-**会话**采用仅追加方式。一个**轮次**领取一条已排队的后续消息，等待前一轮次的检查点，并可与其共用 `running` 区间（[决策](../.agents/notes/implemented/simplification/2026-07-17-one-send-one-turn.md)）；注入不领取输入。一个**步骤**包含一次模型请求及其工具。[时序](agent-lifecycle.md)中的引号标记持久事件。
+**会话**采用仅追加方式。一个**轮次**领取一条已排队的后续消息，等待前一轮次的检查点，并可与其共用 `running` 区间（[决策](../.agents/notes/implemented/simplification/2026-07-17-one-send-one-turn.md)）；注入不领取输入。一个**步骤**包含一次模型请求及其工具。新建与持久化恢复会先取得精确的未发布 `SessionPreparation`；只有基于该 Session 的私有设置准备完毕后，系统才会发布 agent 与会话（[决策](../.agents/notes/implemented/architecture/2026-08-05-session-preparation.md)）。[时序](agent-lifecycle.md)中的引号标记持久事件。

 创建时若未提供 id，流程会生成 `<config-id>-session-<uuid>`；`sessionId` 用于恢复或创建会话，而 `resumeSessionId` 要求已有历史。恢复流程在发布前还原沿袭关系和委托深度；初始化失败会发出 `agent-loop/config-start-failed`。

 ### 轮次流程

 ```text
-choose declarative identity and fresh/resume path
-  -> prepare private session + agent.ctx -> await unpublished setup
+choose declarative identity and acquire fresh/restored SessionPreparation
+  -> prepare private agent.ctx around exact Session -> await unpublished setup -> invoke optional synchronous setup commit
  -> enter session + agent -> session/created -> agent/created
  -> enable driving -> agent/session-start(source) -> start driver
 forever:
@@ -108,7 +108,7 @@ export interface Config {

 Depends on: [`AgentOptions`](core-data-structures/core.md) · [`SessionId`](core-data-structures/core.md)

-Source: [`packages/core/agent-loop/src/index.ts:212`](../packages/core/agent-loop/src/index.ts)
+Source: [`packages/core/agent-loop/src/index.ts:236`](../packages/core/agent-loop/src/index.ts)

 ## `@deepseek-ai/dsh-agent-spine-demo`

@@ -405,6 +405,8 @@ Source: [`packages/compact/compact-basic/src/types.ts:38`](../packages/compact/c

 ## `@deepseek-ai/dsh-compact-tool-result-prune`

+Requires: `tokenMeter`
+
 ```ts config-catalog
 /** Character-budget policy for deterministic tool-result pruning. */
 export interface ToolResultPruneConfig {
@@ -1135,13 +1137,15 @@ export interface Config {
  packChunks?: boolean
  /** Physical encoding; defaults to checksummed Zstandard frames. */
  compression?: JsonlCompression
+  /** Maximum cold Session preparations retained for history-to-resume reuse. */
+  preparedSessionCacheSize?: number
 }

 /** Physical encoding selected for JSONL session artifacts. */
 export type JsonlCompression = 'zstd' | 'none'
 ```

-Source: [`packages/session-persistence/session-persistence-jsonl/src/index.ts:40`](../packages/session-persistence/session-persistence-jsonl/src/index.ts)
+Source: [`packages/session-persistence/session-persistence-jsonl/src/index.ts:58`](../packages/session-persistence/session-persistence-jsonl/src/index.ts)

 ## `@deepseek-ai/dsh-session-persistence-sqlite`

@@ -1167,6 +1171,8 @@ export interface Config {
   * (network mounts). See {@link JournalMode}.
   */
  journalMode?: JournalMode
+  /** Maximum cold Session preparations retained for history-to-resume reuse. */
+  preparedSessionCacheSize?: number
 }

 /**
@@ -1180,7 +1186,7 @@ export interface Config {
 export type JournalMode = 'wal' | 'delete' | 'truncate' | 'persist'
 ```

-Source: [`packages/session-persistence/session-persistence-sqlite/src/index.ts:58`](../packages/session-persistence/session-persistence-sqlite/src/index.ts)
+Source: [`packages/session-persistence/session-persistence-sqlite/src/index.ts:66`](../packages/session-persistence/session-persistence-sqlite/src/index.ts)

 ## `@deepseek-ai/dsh-session-projection-cache`

@@ -297,7 +297,7 @@ A declarative agent entry failed before it could publish a live agent. Consumers

 Types: [SessionId](../core-data-structures/core.md)

-Source: [`packages/core/agent-loop/src/index.ts:158`](../../packages/core/agent-loop/src/index.ts)
+Source: [`packages/core/agent-loop/src/index.ts:182`](../../packages/core/agent-loop/src/index.ts)

 ## `approval/*`

@@ -535,7 +535,7 @@ Creation announcement during session publication. A synchronous throw vetoes and

 Types: [Scoped](../core-data-structures/scope.md) · [Session](../core-data-structures/session.md)

-Source: [`packages/core/session/src/index.ts:71`](../../packages/core/session/src/index.ts)
+Source: [`packages/core/session/src/index.ts:73`](../../packages/core/session/src/index.ts)

 ### `session/disposed` — emit

@@ -556,7 +556,7 @@ Emitted once when an announced session leaves the store, including publication r

 Types: [Scoped](../core-data-structures/scope.md) · [Session](../core-data-structures/session.md)

-Source: [`packages/core/session/src/index.ts:81`](../../packages/core/session/src/index.ts)
+Source: [`packages/core/session/src/index.ts:83`](../../packages/core/session/src/index.ts)

 ### `session/event` — emit

@@ -579,7 +579,7 @@ Post-commit, fire-and-forget append feed. The listener snapshot resolves before

 Types: [Scoped](../core-data-structures/scope.md) · [Session](../core-data-structures/session.md) · [SessionEvent](../core-data-structures/core.md)

-Source: [`packages/core/session/src/index.ts:93`](../../packages/core/session/src/index.ts)
+Source: [`packages/core/session/src/index.ts:95`](../../packages/core/session/src/index.ts)

 ### `session/flush` — parallel

@@ -599,7 +599,7 @@ Awaited parallel durability checkpoint: every listener runs and the caller await

 Types: [Scoped](../core-data-structures/scope.md) · [Session](../core-data-structures/session.md)

-Source: [`packages/core/session/src/index.ts:102`](../../packages/core/session/src/index.ts)
+Source: [`packages/core/session/src/index.ts:104`](../../packages/core/session/src/index.ts)

 ## `settings/*`

@@ -44,7 +44,7 @@ async resume(ownerCtx: Context, options: ResumeAgentOptions): Promise<AgentHandl

 Types: [Agent](../core-data-structures/core.md) · [AgentOptions](../core-data-structures/core.md) · [SessionHeader](../core-data-structures/persistence.md) · [SessionId](../core-data-structures/core.md)

-Source: [`packages/core/agent-loop/src/index.ts:253`](../../packages/core/agent-loop/src/index.ts)
+Source: [`packages/core/agent-loop/src/index.ts:277`](../../packages/core/agent-loop/src/index.ts)

 ## `ctx.agents` — `AgentRegistry`

@@ -1175,46 +1175,59 @@ abstract create(meta: SessionHeader): Promise<void>
 abstract append(id: SessionId, events: readonly SessionEvent[]): Promise<void>

 /**
- * Load a header and balanced contiguous log. A complete interrupted final
- * turn is preserved and durably closed with missing tool errors plus any open
- * step and turn boundaries; only a torn final record is discarded. Unknown
- * versions and corruption in the committed prefix reject. Implementations
- * MUST NOT crash-repair an identity still bound to a live Session: a balanced
- * live log may return with its stored header as a durable snapshot, while an
- * open live turn rejects.
- * A coordinator-backed cold load reserves the identity across storage awaits,
- * so concurrent publication of a same-id live Session rejects.
- * Returned events are detached, and every identified message is deeply
- * frozen. Coordinator-backed implementations upgrade supported pre-identity
- * message events before validation; other malformed messages reject before
- * any stored event is returned.
+ * Prepare the exact unpublished Session used by resume. Implementations may
+ * reuse object graphs retained by an earlier {@link inspect} after confirming
+ * their durable revision is still current; disposal releases an unpublished
+ * reservation. Revision retries require the durable log to remain unchanged
+ * for one read/check round trip; continuous external writers may delay completion.
+ * @param id - persisted session to prepare.
+ * @param signal - optional cancellation for preparation work.
+ * @returns one owned unpublished Session preparation.
+ */
+async prepare(id: SessionId, signal?: AbortSignal): Promise<SessionPreparation>
+
+/**
+ * Load an immutable balanced logical view and commit any required cold
+ * recovery. A complete interrupted final turn is preserved and durably
+ * closed with missing tool errors plus any open step and turn boundaries;
+ * only a torn final record is discarded. Unknown versions and corruption in
+ * the committed prefix reject. Implementations MUST NOT crash-repair an
+ * identity still bound to a live Session: a balanced live log may return as a
+ * durable snapshot, while an open live turn rejects. Returned values may be
+ * shared with immutable live or prepared state and must not be mutated.
+ * Revision-based implementations may wait for one stable read/check round trip.
 * @param id - the persisted session to reload.
 * @returns the header and a log ending on a balanced `turn/end`.
 */
-abstract load(id: SessionId): Promise<{ meta: SessionHeader; events: SessionEvent[] }>
+abstract load(id: SessionId): Promise<SessionInspection>

 /**
- * Inspect a header and its valid contiguous stored prefix without repairing
- * a torn tail, closing an interrupted turn, or publishing coordinator state.
- * This read is serialized with writes for the same id and returns detached
- * values with upgraded, deeply frozen identified messages, so observers
- * cannot mutate message identity/content or backend-owned state. Other
- * malformed messages reject.
+ * Inspect an immutable logical session without committing recovery or
+ * publishing it. A cold complete interrupted turn receives synthetic closers
+ * in memory and a torn physical tail remains untouched. An already-live
+ * Session instead yields its current immutable snapshot, which may contain an
+ * open turn and its `session/end-seed` boundary. Coordinator-backed
+ * implementations retain the exact cold unpublished Session for bounded
+ * reuse by a later {@link prepare}. A stale ready source is reloaded; a source
+ * already committing or reserved for resume remains exclusive, and inspection
+ * may borrow its immutable view. Callers borrow only the immutable header and
+ * log. Continuous external writers may delay revision convergence.
 * @param id - the persisted session to inspect.
 * @param signal - optional cancellation for queued and backend read work.
- * @returns the header and valid stored event prefix exactly as observed.
+ * @returns the validated header and current logical event log.
 */
-abstract inspect(id: SessionId, signal?: AbortSignal): Promise<{ meta: SessionHeader; events: SessionEvent[] }>
+abstract inspect(id: SessionId, signal?: AbortSignal): Promise<SessionInspection>

 /**
 * Read the stored events from `fromSeq` onward — the read-from-seq
 * primitive for read models that resume from a watermark (e.g. a persisted
- * projection cache folding only the tail past its checkpoint). Like
- * {@link inspect} it is non-mutating and detached: no torn-tail truncation,
- * no synthetic closers, no coordinator-state publication; only events from
- * the valid contiguous stored prefix are returned, so a torn fragment never
- * reaches the caller. `fromSeq` at or beyond the stored prefix returns an
- * empty event list (never an error). Backends whose medium can seek by seq
+ * projection cache folding only the tail past its checkpoint). Unlike
+ * {@link inspect}, it is a detached physical suffix read: no preparation
+ * cache, torn-tail truncation, synthetic closers, or coordinator-state
+ * publication. Only events from the valid contiguous stored prefix are
+ * returned, so a torn fragment never reaches the caller. `fromSeq` at or
+ * beyond the stored prefix returns an empty event list (never an error).
+ * Backends whose medium can seek by seq
 * (SQLite) read only the suffix; sequential media (JSONL, both encodings)
 * still parse the whole artifact and skip forward — the primitive bounds
 * what is RETURNED and refolded, not every backend's physical read.
@@ -1245,9 +1258,9 @@ abstract list(signal?: AbortSignal): Promise<SessionHeader[]>
 abstract listSnapshots(signal?: AbortSignal): Promise<SessionPersistenceSnapshot[]>
 ```

-Types: [SessionEvent](../core-data-structures/core.md) · [SessionHeader](../core-data-structures/persistence.md) · [SessionId](../core-data-structures/core.md) · [SessionLocation](../core-data-structures/persistence.md) · [SessionPersistenceSnapshot](../core-data-structures/persistence.md)
+Types: [SessionEvent](../core-data-structures/core.md) · [SessionHeader](../core-data-structures/persistence.md) · [SessionId](../core-data-structures/core.md) · [SessionInspection](../core-data-structures/persistence.md) · [SessionLocation](../core-data-structures/persistence.md) · [SessionPersistenceSnapshot](../core-data-structures/persistence.md) · [SessionPreparation](../core-data-structures/persistence.md)

-Source: [`packages/session-persistence/session-persistence/src/index.ts:52`](../../packages/session-persistence/session-persistence/src/index.ts)
+Source: [`packages/session-persistence/session-persistence/src/index.ts:70`](../../packages/session-persistence/session-persistence/src/index.ts)

 ## `ctx.sessionProjectionCache` — `SessionProjectionCache`

@@ -1602,13 +1615,17 @@ create(id?: SessionId, options?: CreateSessionOptions): Session
 * before the driver's closing events commit, dropping them.
 *
 * @param id - the session id; omitted, the store mints `session-<n>`.
- * @param options - seed events and/or creation metadata for the header.
+ * @param options - seed events and/or creation metadata for the header. With
+ *   `seedSource: 'persistence'`, metadata and events must be fresh detached
+ *   graphs whose ownership transfers to this call: they are validated and
+ *   frozen in place through {@link Session.fromRestore}, so the caller must
+ *   retain no mutable aliases.
 * @returns the constructed session, NOT yet in the store.
 * @throws if a session with `id` already exists, metadata is not a plain
 *   lossless-JSON record with valid scalar fields, or `meta.cwd` is a
 *   non-absolute path.
 */
-prepare(id?: SessionId, options?: CreateSessionOptions): Session
+prepare(id?: SessionId, options?: PrepareSessionOptions): Session

 /**
 * Enter a {@link prepare}d session into the store: install the module-private
@@ -1688,9 +1705,9 @@ list(): Session[]
 fork(source: SessionForkSource, boundary?: number, childSessionId?: SessionId): Session
 ```

-Types: [CreateSessionOptions](../core-data-structures/persistence.md) · [Session](../core-data-structures/session.md) · [SessionId](../core-data-structures/core.md)
+Types: [CreateSessionOptions](../core-data-structures/persistence.md) · [PrepareSessionOptions](../core-data-structures/persistence.md) · [Session](../core-data-structures/session.md) · [SessionId](../core-data-structures/core.md)

-Source: [`packages/core/session/src/index.ts:767`](../../packages/core/session/src/index.ts)
+Source: [`packages/core/session/src/index.ts:800`](../../packages/core/session/src/index.ts)

 ## `ctx.sessionTitle` — `SessionTitleService`

@@ -2322,7 +2339,8 @@ Replay owner for one service-wide estimator and isolated per-session folds.
 measure(session: Session, requestHeader?: EpochHeader): TokenMeasurement

 /**
- * Heuristically price one model-visible message.
+ * Heuristically price one model-visible message (instance face of the pure
+ * `estimateMessage` export from `estimate.ts`).
 * @param message - message to price without mutation.
 * @returns content and role-framing tokens under the fixed service heuristic.
 */
@@ -2331,7 +2349,7 @@ estimateMessage(message: Message): number

 Types: [EpochHeader](../core-data-structures/session.md) · [Message](../core-data-structures/core.md) · [Session](../core-data-structures/session.md) · [TokenMeasurement](../core-data-structures/token-meter.md)

-Source: [`packages/llm/token-meter/src/index.ts:85`](../../packages/llm/token-meter/src/index.ts)
+Source: [`packages/llm/token-meter/src/index.ts:74`](../../packages/llm/token-meter/src/index.ts)

 ## `ctx.toolResultPrune` — `ToolResultPruneService`

@@ -2357,7 +2375,10 @@ pruneContent(blocks: readonly ContentBlock[]): ContentBlock[] | null
 /**
 * Prune every over-budget tool result from one stable current-surface snapshot.
 * Each replacement preserves the complete event data except for `content`,
- * and points at the shadowed node for durable provenance and replay.
+ * points at the shadowed node for durable provenance and replay, and is
+ * immediately preceded by a `compact/prune` shadow-price event pricing the
+ * shadowed node through the injected token meter, so pure consumers can
+ * subtract it without per-node state.
 * @param session - session whose current surface is rewritten.
 * @returns landed replacements and aggregate Unicode-code-point savings.
 * @throws when the session rejects a replacement; replacements committed
@@ -2368,7 +2389,7 @@ pruneSession(session: Session): PruneResult

 Types: [ContentBlock](../core-data-structures/core.md) · [PruneResult](../core-data-structures/compaction.md) · [Session](../core-data-structures/session.md)

-Source: [`packages/compact/compact-tool-result-prune/src/index.ts:40`](../../packages/compact/compact-tool-result-prune/src/index.ts)
+Source: [`packages/compact/compact-tool-result-prune/src/index.ts:44`](../../packages/compact/compact-tool-result-prune/src/index.ts)

 ## `ctx.tools` — `ToolRegistry`

@@ -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 docs/core-data-structures/persistence.md
-persistence.md: ed19af4e739c153ce1beec7c1e8de06f0c0bca53
-persistence.zh.md: 83d8ba3c0eabe57b9df661fb86ec05d3db98d8b6
+persistence.md: 0968496201defa869d94925e8e5ae3c5da1bbd37
+persistence.zh.md: efb01427b4355e531fb9b86922223cf27d3b3db0
@@ -4,7 +4,7 @@ English | [中文](persistence.zh.md)

 The **durability seam** for the event log. [session.md](session.md) describes the in-memory `Session` — the append-only `SessionEvent` log that is the source of truth. This page describes how that log is made durable: the abstract `SessionPersistence` service, its backends, the flush checkpoint, crash recovery, and the metadata header that travels alongside the log. The event vocabulary the log carries is enumerated, member by member, in the generated [persistence log event catalog](../persistence-catalog.md).

-The seam is a textbook [capability seam](../../.agents/notes/implemented/architecture/2026-06-13-capability-seams.md): one abstract service ([dsh-session-persistence](../../packages/session-persistence/session-persistence), `ctx.sessionPersistence`) defining locate/create/append, crash-repairing load, non-mutating inspect, and lightweight list/snapshot observation over the existing `SessionEvent` — **no parallel persisted type** — and two interchangeable backends implementing the same contract. See the [session-persistence Agent Note](../../.agents/notes/implemented/architecture/2026-06-14-session-persistence.md).
+The seam is a textbook [capability seam](../../.agents/notes/implemented/architecture/2026-06-13-capability-seams.md): one abstract service ([dsh-session-persistence](../../packages/session-persistence/session-persistence), `ctx.sessionPersistence`) defining locate/create/append, reusable Session preparation, logical load/inspect, physical suffix reads, and lightweight list/snapshot observation over the existing `SessionEvent` — **no parallel persisted event type** — and two interchangeable backends implementing the same contract. See the [session-persistence Agent Note](../../.agents/notes/implemented/architecture/2026-06-14-session-persistence.md).

 ## The flush checkpoint

@@ -14,9 +14,9 @@ The seam is a textbook [capability seam](../../.agents/notes/implemented/archite

 A backend that reloads a log crashed mid-turn finds an open `turn/start` with no `turn/end`. It does **not** truncate — a single turn can be huge in a long-horizon task (many steps, large tool output), and those events were durably appended before the crash. Instead it closes the orphaned turn with a synthetic `turn/end { reason: { kind: 'interrupted' } }`, keeping the interrupted execution balanced without changing any standalone events before or after it. `interrupted` is the one `TurnEndReason` no loop emits (see [session.md](session.md#why-a-turn-ended-turnendreasonmap)).

-Repair applies only to cold sessions. For a live id, `SessionPersistence.load(id)` snapshots the in-memory log, waits until that snapshot is durable, and returns it with the stored header only when balanced; an open live turn rejects rather than receiving synthetic interruption boundaries. A coordinator-backed cold load reserves the id across backend reads and repair writes, so concurrent publication of a same-id live session rejects and rolls back. HMR also adopts a live prefix without closing its active turn.
+Repair applies only to cold sessions. For a live id, `SessionPersistence.load(id)` waits until the authoritative in-memory snapshot is durable and returns it only when balanced; an open live turn rejects rather than receiving synthetic interruption boundaries. HMR adopts a live prefix without closing its active turn.

-`SessionPersistence.inspect(id)` is the observer counterpart to recovery: it returns a detached valid stored prefix without truncating a torn record, adding interruption closers, or publishing write state. Same-id serialization keeps it coherent with backend writes. Derived read models use `inspect`, never `load`, so observing a checkpointed open turn cannot mutate the log if live ownership begins concurrently.
+`SessionPersistence.inspect(id)` constructs an immutable logical Session without publishing it or writing recovery. Cold inspection balances an interrupted turn in memory while leaving torn physical tails untouched; inspection of an already-live Session borrows its current immutable snapshot and may therefore contain an open turn. Coordinator-backed implementations retain the exact cold unpublished Session in a bounded LRU, so repeated history reads and a later `prepare(id)` share one read, decompression, validation, freeze, and Session construction. `prepare(id)` reserves the Session, commits pending repair, and returns a disposable publication handle; `load(id)` uses the same machinery to commit repair without publication. The [Session preparation decision](../../.agents/notes/implemented/architecture/2026-08-05-session-preparation.md) owns this lifecycle.

 ## `SessionLocation` — optional per-session artifact target

@@ -82,7 +82,7 @@ interface SessionHeader {

 ## `CreateSessionOptions` — seeding and metadata

-Creating a `Session` through the store takes a `seed` (initial replay or fork history) and `meta` (the storage-level fields the store folds into a `SessionHeader`). The store fills in `version`/`id` and defaults `createdAt`; the caller supplies the validated absolute `cwd`, the `parentSession` lineage, the `seedLength` seed boundary, the optional coarse `origin`, the `delegationDepth`, and — only when reconstructing a persisted session — the original `createdAt` to preserve it. `origin: 'subagent'` lets product navigation hide duplicate child rows; it does not prove that a descriptor is valid or that the child can resume.
+Creating a `Session` through the store takes a `seed` (initial replay or fork history) and `meta` (the storage-level fields the store folds into a `SessionHeader`). The store fills in `version`/`id` and defaults `createdAt`; the caller may supply the validated absolute `cwd`, the `parentSession` lineage, the `seedLength` seed boundary, the optional coarse `origin`, the `delegationDepth`, and an existing `createdAt`. `origin: 'subagent'` lets product navigation hide duplicate child rows; it does not prove that a descriptor is valid or that the child can resume.

 ```ts type-equiv
 /**
@@ -110,6 +110,72 @@ interface CreateSessionOptions {

 Replay/fork is therefore `ctx.sessions.create(id, { seed: seedEvents })`; resuming a *persisted* session into a live agent is `ctx.agents.resume({ resumeSessionId })`.

+## Preparation and restoration ownership
+
+`SessionStore.prepare()` accepts ordinary creation options or fresh persistence graphs transferred through `RestoredSessionOptions`. The restoration branch validates and freezes the transferred header and events in place, so callers must retain no mutable aliases. `SessionPreparation` then owns the exact unpublished Session until publication or rollback; disposal is synchronous and idempotent. Persistence inspection exposes only `SessionInspection`, an immutable logical view borrowed from the same prepared Session.
+
+```ts type-equiv
+/**
+ * Fresh storage values transferred to {@link SessionStore.prepare} without a
+ * second serialization copy. Callers retain no mutable aliases.
+ */
+interface RestoredSessionOptions {
+  /** Fresh detached storage events to validate and freeze in place. */
+  readonly seed: SessionEvent[]
+  /** Fresh detached storage metadata to validate and freeze in place. */
+  readonly meta: SessionHeader
+  /** Select the persistence ownership-transfer path. */
+  readonly seedSource: 'persistence'
+}
+```
+
+```ts type-equiv
+/** Inputs accepted while constructing an unpublished Session. */
+type PrepareSessionOptions =
+  | (CreateSessionOptions & { readonly seedSource?: undefined })
+  | RestoredSessionOptions
+```
+
+```ts type-equiv
+/** Options for a preparation whose provider retains unpublished state. */
+interface SessionPreparationOptions {
+  /** Release provider-owned state when the Session was not published. */
+  readonly release?: () => void
+}
+```
+
+```ts public-api
+/**
+ * One exact unpublished Session and the provider state that keeps it usable.
+ * Disposal is synchronous and idempotent. Providers decide whether release
+ * returns the Session to a cache or discards it; publication may consume that
+ * state before disposal, making the callback a no-op.
+ */
+declare class SessionPreparation implements Disposable {
+  /** The exact Session to use for setup and publication. */
+  readonly session: Session;
+  /**
+   * Wrap an unpublished Session in one preparation lifetime.
+   * @param session - exact unpublished Session.
+   * @param options - optional provider release behavior.
+   * @returns a preparation disposed after publication or rollback.
+   */
+  static create(session: Session, options?: SessionPreparationOptions): SessionPreparation;
+  /** Release provider state once when this preparation leaves its caller. */
+  [Symbol.dispose](): void;
+}
+```
+
+```ts type-equiv
+/** Immutable logical session prepared from persistence or a live owner. */
+interface SessionInspection {
+  /** Validated immutable session metadata. */
+  readonly meta: SessionHeader
+  /** Validated contiguous logical event log. */
+  readonly events: readonly SessionEvent[]
+}
+```
+
 ## Lightweight source revisions

 Consumers of derived state compare a cheap opaque revision before loading a full event log. The persistence backend owns its representation and changes it transactionally with append or mutating load repair; callers compare it only for equality.
@@ -134,7 +200,7 @@ interface SessionPersistenceSnapshot {

 ## The backends

-Both implement the same abstract `SessionPersistence` (locate/create/append/load/inspect/list/listSnapshots over `SessionEvent`, with optional cancellation on observation methods) and pass `runPersistenceContract`, proving the seam is genuinely backend-agnostic:
+Both implement the same abstract `SessionPersistence` (locate/create/append/prepare/load/inspect/readFrom/list/listSnapshots over `SessionEvent`, with optional cancellation on observation methods) and pass `runPersistenceContract`, proving the seam is genuinely backend-agnostic:

 - **[dsh-session-persistence-jsonl](../../packages/session-persistence/session-persistence-jsonl)** — an append-only logical JSONL log per session, stored as checksummed concatenated Zstandard frames by default or raw lines by configuration, with crash-safe atomic writes, interrupted-turn recovery, and a read/replay path.
 - **[dsh-session-persistence-sqlite](../../packages/session-persistence/session-persistence-sqlite)** — `node:sqlite`, one row per `SessionEvent`. The row shape `(session_id, seq, type, time, data, source_event_seqs, surface_op)` maps 1:1 onto the event, including optional surface metadata, so there is no parallel persisted schema to keep in sync.
@@ -4,7 +4,7 @@

 事件日志的**持久性 seam**。[session.md](session.md) 描述了内存中的 `Session`：仅追加的 `SessionEvent` 日志即为真源。本页描述如何使该日志持久化：抽象的 `SessionPersistence` 服务、它的后端、flush 检查点、崩溃恢复，以及随日志一同存储的元数据头。日志承载的事件词汇在生成的[持久化日志事件目录](../persistence-catalog.md)中逐项列举。

-该 seam 是典型的[能力 seam](../../.agents/notes/implemented/architecture/2026-06-13-capability-seams.md)：一个抽象服务（[dsh-session-persistence](../../packages/session-persistence/session-persistence)，`ctx.sessionPersistence`）在现有 `SessionEvent` 上定义 locate/create/append、会执行崩溃修复的 load、不会修改数据的 inspect，以及轻量的 list/snapshot 观察——**没有平行的持久化类型**——以及两个实现同一契约的可互换后端。见 [session-persistence Agent Note（agent 决策记录）](../../.agents/notes/implemented/architecture/2026-06-14-session-persistence.md)。
+该 seam 是典型的[能力 seam](../../.agents/notes/implemented/architecture/2026-06-13-capability-seams.md)：一个抽象服务（[dsh-session-persistence](../../packages/session-persistence/session-persistence)，`ctx.sessionPersistence`）在现有 `SessionEvent` 上定义 locate/create/append、可复用的 Session 准备流程、逻辑 load/inspect、物理后缀读取，以及轻量的 list/snapshot 观察——**没有平行的持久化事件类型**——以及两个实现同一契约的可互换后端。见 [session-persistence Agent Note](../../.agents/notes/implemented/architecture/2026-06-14-session-persistence.md)。

 ## flush 检查点

@@ -14,9 +14,9 @@

 后端重新加载一个在轮次中途崩溃的日志时，会发现一个已打开的 `turn/start` 却没有 `turn/end`。它**不会**截断日志：在长周期任务中，单个轮次可能非常庞大（许多步骤、大量工具输出），而这些事件在崩溃前已被持久追加。后端改为用一个合成的 `turn/end { reason: { kind: 'interrupted' } }` 关闭这个遗留轮次，在不改变其前后任何独立事件的情况下配平被中断的执行。`interrupted` 是唯一一个不由循环发出的 `TurnEndReason`（见 [session.md](session.md#why-a-turn-ended-turnendreasonmap)）。

-修复仅适用于冷会话。对于活跃 id，`SessionPersistence.load(id)` 会对内存日志拍摄快照，等待该快照完成持久化，并且只在日志平衡时连同已存储的 header 返回；若活跃轮次仍未闭合，则拒绝操作，而不是添加合成的中断边界。由协调器管理的冷加载会在后端读取和修复写入期间占用该 id，因此并发发布同 id 的活跃会话会被拒绝并回滚。HMR 也会接管活跃前缀，而不会关闭其中正在进行的轮次。
+修复仅适用于冷会话。对于活跃 id，`SessionPersistence.load(id)` 会等待权威内存快照完成持久化，并且只在日志平衡时返回；若活跃轮次仍未闭合，则拒绝操作，而不是添加合成的中断边界。HMR 会接管活跃前缀，而不会关闭其中正在进行的轮次。

-`SessionPersistence.inspect(id)` 是恢复机制面向观察方的对等操作：它返回已存储有效前缀的独立副本，不截断不完整记录、不添加中断结束事件，也不发布写入状态。同 id 串行化确保它与后端写入保持一致。派生读取模型使用 `inspect`，绝不使用 `load`，因此即使活跃所有权并发建立，观察已落检查点但仍未闭合的轮次也不会修改日志。
+`SessionPersistence.inspect(id)` 会构造一个不可变的逻辑 Session，但不发布它，也不写入恢复内容。冷检查会在内存中配平中断的 turn，同时保持撕裂的物理尾部不变；检查已经实时存在的 Session 则借用其当前不可变快照，因此可能包含打开的 turn。使用协调器的实现会在有界 LRU 中保留这个精确的冷未发布 Session，因此重复历史读取与后续 `prepare(id)` 可复用同一次读取、解压、验证、冻结及 Session 构造。`prepare(id)` 会预留该 Session、提交待处理修复并返回可 dispose 的发布句柄；`load(id)` 使用相同机制提交修复，但不会发布 Session。该生命周期由 [Session 准备阶段决策](../../.agents/notes/implemented/architecture/2026-08-05-session-preparation.md)定义。

 ## `SessionLocation`——可选的逐会话产物目标

@@ -82,7 +82,7 @@ interface SessionHeader {

 ## `CreateSessionOptions`：seed 与元数据

-通过 store 创建 `Session` 时会接收 `seed`（初始回放或 fork 历史）与 `meta`（store 折叠进 `SessionHeader` 的存储层字段）。store 填充 `version`/`id` 并为 `createdAt` 提供默认值；调用方提供已校验的绝对 `cwd`、`parentSession` 谱系、`seedLength` 种子边界、可选的粗粒度 `origin`、`delegationDepth`，以及——仅在重建已持久化会话时——需要保留的原始 `createdAt`。`origin: 'subagent'` 让产品导航能够隐藏重复的 child 行；它不证明描述符有效，也不证明 child 可以恢复。
+通过 store 创建 `Session` 时会接收 `seed`（初始回放或 fork 历史）与 `meta`（store 折叠进 `SessionHeader` 的存储层字段）。store 填充 `version`/`id` 并为 `createdAt` 提供默认值；调用方可以提供已校验的绝对 `cwd`、`parentSession` 谱系、`seedLength` 种子边界、可选的粗粒度 `origin`、`delegationDepth` 以及已有的 `createdAt`。`origin: 'subagent'` 让产品导航能够隐藏重复的 child 行；它不证明描述符有效，也不证明 child 可以恢复。

 ```ts type-equiv
 /**
@@ -110,6 +110,72 @@ interface CreateSessionOptions {

 因此，回放/fork 的调用方式为 `ctx.sessions.create(id, { seed: seedEvents })`；将一个*持久化*会话恢复为活跃 agent 的调用方式为 `ctx.agents.resume({ resumeSessionId })`。

+## 准备与恢复所有权
+
+`SessionStore.prepare()` 接收普通创建选项，或通过 `RestoredSessionOptions` 转移所有权的新鲜持久化对象图。恢复分支会直接验证并冻结转移来的 header 与事件，因此调用方不得保留可变别名。`SessionPreparation` 随后持有该精确的未发布 Session，直至发布或回滚；dispose 是同步且幂等的。持久化检查只暴露 `SessionInspection`，即从同一个已准备 Session 借用的不可变逻辑视图。
+
+```ts type-equiv
+/**
+ * Fresh storage values transferred to {@link SessionStore.prepare} without a
+ * second serialization copy. Callers retain no mutable aliases.
+ */
+interface RestoredSessionOptions {
+  /** Fresh detached storage events to validate and freeze in place. */
+  readonly seed: SessionEvent[]
+  /** Fresh detached storage metadata to validate and freeze in place. */
+  readonly meta: SessionHeader
+  /** Select the persistence ownership-transfer path. */
+  readonly seedSource: 'persistence'
+}
+```
+
+```ts type-equiv
+/** Inputs accepted while constructing an unpublished Session. */
+type PrepareSessionOptions =
+  | (CreateSessionOptions & { readonly seedSource?: undefined })
+  | RestoredSessionOptions
+```
+
+```ts type-equiv
+/** Options for a preparation whose provider retains unpublished state. */
+interface SessionPreparationOptions {
+  /** Release provider-owned state when the Session was not published. */
+  readonly release?: () => void
+}
+```
+
+```ts public-api
+/**
+ * One exact unpublished Session and the provider state that keeps it usable.
+ * Disposal is synchronous and idempotent. Providers decide whether release
+ * returns the Session to a cache or discards it; publication may consume that
+ * state before disposal, making the callback a no-op.
+ */
+declare class SessionPreparation implements Disposable {
+  /** The exact Session to use for setup and publication. */
+  readonly session: Session;
+  /**
+   * Wrap an unpublished Session in one preparation lifetime.
+   * @param session - exact unpublished Session.
+   * @param options - optional provider release behavior.
+   * @returns a preparation disposed after publication or rollback.
+   */
+  static create(session: Session, options?: SessionPreparationOptions): SessionPreparation;
+  /** Release provider state once when this preparation leaves its caller. */
+  [Symbol.dispose](): void;
+}
+```
+
+```ts type-equiv
+/** Immutable logical session prepared from persistence or a live owner. */
+interface SessionInspection {
+  /** Validated immutable session metadata. */
+  readonly meta: SessionHeader
+  /** Validated contiguous logical event log. */
+  readonly events: readonly SessionEvent[]
+}
+```
+
 ## 轻量源修订号

 派生状态的消费方会在加载完整事件日志之前比较一个低开销的不透明修订号。其表示由持久化后端拥有，并随 append 或会修改数据的 load 修复以事务方式改变；调用方仅比较修订号是否相等。
@@ -134,7 +200,7 @@ interface SessionPersistenceSnapshot {

 ## 后端

-两者都实现同一个抽象 `SessionPersistence`（在 `SessionEvent` 上执行 locate/create/append/load/inspect/list/listSnapshots），并通过 `runPersistenceContract`，证明该 seam 确实与后端无关：
+两者都实现同一个抽象 `SessionPersistence`（在 `SessionEvent` 上执行 locate/create/append/prepare/load/inspect/readFrom/list/listSnapshots，观察方法可选支持取消），并通过 `runPersistenceContract`，证明该 seam 确实与后端无关：

 - **[dsh-session-persistence-jsonl](../../packages/session-persistence/session-persistence-jsonl)**——每个会话一份仅追加的逻辑 JSONL 日志，默认存储为带 checksum 的连续 Zstandard frame，也可配置为原始行；支持崩溃安全的原子写入、被中断轮次的恢复以及读取/回放路径。
 - **[dsh-session-persistence-sqlite](../../packages/session-persistence/session-persistence-sqlite)**：基于 `node:sqlite`，每个 `SessionEvent` 一行。行结构 `(session_id, seq, type, time, data, source_event_seqs, surface_op)` 与事件 1:1 映射（包含可选的 surface 元数据），因此没有需要保持同步的并行持久化 schema。
@@ -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 docs/core-data-structures/session-query.md
-session-query.md: d92af4bac34f7d41457e9e193111c3a53fe8022e
-session-query.zh.md: 8070dfda61a2945fca554939f65ae0f8b85078db
+session-query.md: e7514dd6c3bc20a07395663bff40ce65e1363b78
+session-query.zh.md: 4c3dd4d435dbd8a20fbd4db5da1a7d649c2e6d0b
@@ -338,6 +338,7 @@ The closed code union distinguishes request validation, missing targets, malform
 /** Stable machine-routable failure taxonomy for session reads, traces, and search. */
 type SessionQueryErrorCode =
  | 'SESSION_QUERY_ABORTED'
+  | 'SESSION_QUERY_CORRUPT_SESSION'
  | 'SESSION_QUERY_EVENT_NOT_FOUND'
  | 'SESSION_QUERY_INDEX_FAILED'
  | 'SESSION_QUERY_INVALID_CONFIG'
@@ -338,6 +338,7 @@ interface SessionEventTraceObservation extends SessionEventTrace {
 /** Stable machine-routable failure taxonomy for session reads, traces, and search. */
 type SessionQueryErrorCode =
  | 'SESSION_QUERY_ABORTED'
+  | 'SESSION_QUERY_CORRUPT_SESSION'
  | 'SESSION_QUERY_EVENT_NOT_FOUND'
  | 'SESSION_QUERY_INDEX_FAILED'
  | 'SESSION_QUERY_INVALID_CONFIG'
@@ -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 docs/core-data-structures/session.md
-session.md: 34e5ad8f7836b18412b7d51a6083e638a3908aae
-session.zh.md: e607e9bb07581c5753b48104993c75586611b675
+session.md: fac201b581e395865fd46d51bca1350cbbc46e8e
+session.zh.md: 53dc9d11de895deec72aaf5ea81c70ba87c9c6bd
@@ -400,6 +400,16 @@ declare class Session {
   * @returns a detached session.
   */
  static create(id: SessionId, seed?: readonly SessionEvent[], header?: SessionHeader): Session;
+  /**
+   * Restore a detached session by taking ownership of fresh persistence values.
+   * Storage shape, event envelopes, sequence continuity, surface transitions,
+   * and header fields are validated before the graphs are frozen in place.
+   * @param id - restored session identity.
+   * @param seed - fresh detached events whose ownership is transferred.
+   * @param header - fresh detached metadata whose ownership is transferred.
+   * @returns a restored detached session.
+   */
+  static fromRestore(id: SessionId, seed: readonly SessionEvent[], header: SessionHeader): Session;
  /**
   * An immutable snapshot of the append-only event log. The snapshot is reused
   * until the next append; a previously returned array does not grow later.
@@ -484,15 +494,8 @@ declare class Session {
   */
  deriveMessages(): Message[];
  /**
-   * Project a single event into the LLM message it derives to, or null when
-   * it produces none — a non-surface event (chunk, boundary, log-only record)
-   * or an empty-content assistant/message (which exists only to host usage).
-   * The per-node pure function {@link deriveMessages} folds over the surface;
-   * an external reconstructor (or the dev invariant) folds the same function
-   * over a log prefix's surface to rebuild the exact messages any request was
-   * built from (the reconstructability Agent Note). The returned message is
-   * the already frozen message nested in the event wrapper and shared by
-   * delivery, durable history, and model requests.
+   * Instance face of the pure per-node `deriveEventMessage` export from
+   * `surface.ts`.
   * @param event - the event to project.
   * @returns the derived message, or null when the event produces none.
   */
@@ -402,6 +402,16 @@ declare class Session {
   * @returns a detached session.
   */
  static create(id: SessionId, seed?: readonly SessionEvent[], header?: SessionHeader): Session;
+  /**
+   * Restore a detached session by taking ownership of fresh persistence values.
+   * Storage shape, event envelopes, sequence continuity, surface transitions,
+   * and header fields are validated before the graphs are frozen in place.
+   * @param id - restored session identity.
+   * @param seed - fresh detached events whose ownership is transferred.
+   * @param header - fresh detached metadata whose ownership is transferred.
+   * @returns a restored detached session.
+   */
+  static fromRestore(id: SessionId, seed: readonly SessionEvent[], header: SessionHeader): Session;
  /**
   * An immutable snapshot of the append-only event log. The snapshot is reused
   * until the next append; a previously returned array does not grow later.
@@ -486,15 +496,8 @@ declare class Session {
   */
  deriveMessages(): Message[];
  /**
-   * Project a single event into the LLM message it derives to, or null when
-   * it produces none — a non-surface event (chunk, boundary, log-only record)
-   * or an empty-content assistant/message (which exists only to host usage).
-   * The per-node pure function {@link deriveMessages} folds over the surface;
-   * an external reconstructor (or the dev invariant) folds the same function
-   * over a log prefix's surface to rebuild the exact messages any request was
-   * built from (the reconstructability Agent Note). The returned message is
-   * the already frozen message nested in the event wrapper and shared by
-   * delivery, durable history, and model requests.
+   * Instance face of the pure per-node `deriveEventMessage` export from
+   * `surface.ts`.
   * @param event - the event to project.
   * @returns the derived message, or null when the event produces none.
   */
@@ -7,7 +7,7 @@ This matrix shows which packages dispatch each harness-owned event and which pac

 | Event | Mode | Declared in | Dispatchers | Listeners |
 | --- | --- | --- | --- | --- |
-| `agent-loop/config-start-failed` | `emit` | [`packages/core/agent-loop/src/index.ts:158`](../packages/core/agent-loop/src/index.ts) | [`agent-loop`](../packages/core/agent-loop) (`events.dispatch`) | - |
+| `agent-loop/config-start-failed` | `emit` | [`packages/core/agent-loop/src/index.ts:182`](../packages/core/agent-loop/src/index.ts) | [`agent-loop`](../packages/core/agent-loop) (`events.dispatch`) | - |
 | `agent/created` | `emit` | [`packages/core/agent/src/types.ts:178`](../packages/core/agent/src/types.ts) | [`agent`](../packages/core/agent) (`events.dispatch`) | [`goal-session`](../packages/goal/goal-session) |
 | `agent/disposed` | `emit` | [`packages/core/agent/src/types.ts:187`](../packages/core/agent/src/types.ts) | [`agent`](../packages/core/agent) (`events.dispatch`) | [`agent-loop`](../packages/core/agent-loop), [`goal-session`](../packages/goal/goal-session), [`subagent`](../packages/subagent/subagent) |
 | `agent/error` | `emit` | [`packages/core/agent/src/types.ts:302`](../packages/core/agent/src/types.ts) | [`agent-loop`](../packages/core/agent-loop) (`emitAgentEvent`) | [`acp`](../packages/acp/acp), `apiproxy`, [`goal-session`](../packages/goal/goal-session), [`session-telemetry`](../packages/telemetry/session-telemetry) |
@@ -30,10 +30,10 @@ This matrix shows which packages dispatch each harness-owned event and which pac
 | `goal/changed` | `emit` | [`packages/goal/goal/src/domain.ts:141`](../packages/goal/goal/src/domain.ts) | [`goal`](../packages/goal/goal) (`emit`) | [`goal-session`](../packages/goal/goal-session) |
 | `llm/adapters-updated` | `emit` | [`packages/llm/llm/src/index.ts:69`](../packages/llm/llm/src/index.ts) | [`llm`](../packages/llm/llm) (`events.dispatch`) | `apiproxy`, [`llm`](../packages/llm/llm) |
 | `llm/stream` | `waterfall` | [`packages/llm/llm/src/index.ts:58`](../packages/llm/llm/src/index.ts) | [`llm`](../packages/llm/llm) (`waterfall`) | [`agent-loop`](../packages/core/agent-loop), [`llm`](../packages/llm/llm), [`llm-replay`](../packages/support/llm-replay), [`session-checkpoint-policy`](../packages/session-persistence/session-checkpoint-policy), [`session-title`](../packages/session-title/session-title) |
-| `session/created` | `emit` | [`packages/core/session/src/index.ts:71`](../packages/core/session/src/index.ts) | [`session`](../packages/core/session) (`events.dispatch`) | `apiproxy`, [`compact`](../packages/compact/compact), [`goal`](../packages/goal/goal), [`hook-protocol`](../packages/hooks/hook-protocol), [`jsonrpc`](../packages/ui/jsonrpc), [`llm-retry`](../packages/llm/llm-retry), [`permission`](../packages/ui/permission), [`plan-mode`](../packages/plan/plan-mode), [`session`](../packages/core/session), [`session-persistence`](../packages/session-persistence/session-persistence), [`session-telemetry`](../packages/telemetry/session-telemetry), [`tools`](../packages/core/tools), [`user-approval`](../packages/ui/user-approval) |
-| `session/disposed` | `emit` | [`packages/core/session/src/index.ts:81`](../packages/core/session/src/index.ts) | [`session`](../packages/core/session) (`events.dispatch`) | [`agent-loop`](../packages/core/agent-loop), `apiproxy`, [`session-persistence`](../packages/session-persistence/session-persistence), [`session-projection-cache`](../packages/session-projection/session-projection-cache), [`session-telemetry`](../packages/telemetry/session-telemetry), [`session-title`](../packages/session-title/session-title) |
-| `session/event` | `emit` | [`packages/core/session/src/index.ts:93`](../packages/core/session/src/index.ts) | [`session`](../packages/core/session) (`events.dispatch`) | [`acp`](../packages/acp/acp), [`agent-loop`](../packages/core/agent-loop), `apiproxy`, [`cli-demo`](../packages/examples/cli-demo), [`compact`](../packages/compact/compact), [`compact-basic`](../packages/compact/compact-basic), [`goal`](../packages/goal/goal), [`goal-session`](../packages/goal/goal-session), [`hook-protocol`](../packages/hooks/hook-protocol), [`jsonrpc`](../packages/ui/jsonrpc), [`session`](../packages/core/session), [`session-persistence`](../packages/session-persistence/session-persistence), [`session-projection`](../packages/session-projection/session-projection), [`session-projection-cache`](../packages/session-projection/session-projection-cache), [`session-telemetry`](../packages/telemetry/session-telemetry), [`session-title`](../packages/session-title/session-title), [`token-meter`](../packages/llm/token-meter), [`tools`](../packages/core/tools), [`user-approval`](../packages/ui/user-approval) |
-| `session/flush` | `parallel` | [`packages/core/session/src/index.ts:102`](../packages/core/session/src/index.ts) | [`session`](../packages/core/session) (`events.dispatch`) | [`session-persistence`](../packages/session-persistence/session-persistence), [`session-telemetry`](../packages/telemetry/session-telemetry) |
+| `session/created` | `emit` | [`packages/core/session/src/index.ts:73`](../packages/core/session/src/index.ts) | [`session`](../packages/core/session) (`events.dispatch`) | `apiproxy`, [`compact`](../packages/compact/compact), [`goal`](../packages/goal/goal), [`hook-protocol`](../packages/hooks/hook-protocol), [`jsonrpc`](../packages/ui/jsonrpc), [`llm-retry`](../packages/llm/llm-retry), [`permission`](../packages/ui/permission), [`plan-mode`](../packages/plan/plan-mode), [`session`](../packages/core/session), [`session-persistence`](../packages/session-persistence/session-persistence), [`session-telemetry`](../packages/telemetry/session-telemetry), [`tools`](../packages/core/tools), [`user-approval`](../packages/ui/user-approval) |
+| `session/disposed` | `emit` | [`packages/core/session/src/index.ts:83`](../packages/core/session/src/index.ts) | [`session`](../packages/core/session) (`events.dispatch`) | [`agent-loop`](../packages/core/agent-loop), `apiproxy`, [`session-persistence`](../packages/session-persistence/session-persistence), [`session-projection-cache`](../packages/session-projection/session-projection-cache), [`session-telemetry`](../packages/telemetry/session-telemetry), [`session-title`](../packages/session-title/session-title) |
+| `session/event` | `emit` | [`packages/core/session/src/index.ts:95`](../packages/core/session/src/index.ts) | [`session`](../packages/core/session) (`events.dispatch`) | [`acp`](../packages/acp/acp), [`agent-loop`](../packages/core/agent-loop), `apiproxy`, [`cli-demo`](../packages/examples/cli-demo), [`compact`](../packages/compact/compact), [`compact-basic`](../packages/compact/compact-basic), [`goal`](../packages/goal/goal), [`goal-session`](../packages/goal/goal-session), [`hook-protocol`](../packages/hooks/hook-protocol), [`jsonrpc`](../packages/ui/jsonrpc), [`session`](../packages/core/session), [`session-persistence`](../packages/session-persistence/session-persistence), [`session-projection`](../packages/session-projection/session-projection), [`session-projection-cache`](../packages/session-projection/session-projection-cache), [`session-telemetry`](../packages/telemetry/session-telemetry), [`session-title`](../packages/session-title/session-title), [`token-meter`](../packages/llm/token-meter), [`tools`](../packages/core/tools), [`user-approval`](../packages/ui/user-approval) |
+| `session/flush` | `parallel` | [`packages/core/session/src/index.ts:104`](../packages/core/session/src/index.ts) | [`session`](../packages/core/session) (`events.dispatch`) | [`session-persistence`](../packages/session-persistence/session-persistence), [`session-telemetry`](../packages/telemetry/session-telemetry) |
 | `settings/document-updated` | `emit` | [`packages/settings/settings/src/index.ts:150`](../packages/settings/settings/src/index.ts) | [`settings`](../packages/settings/settings) (`events.dispatch`) | `apiproxy` |
 | `settings/updated` | `emit` | [`packages/settings/settings/src/index.ts:137`](../packages/settings/settings/src/index.ts) | [`settings`](../packages/settings/settings) (`events.dispatch`) | [`settings`](../packages/settings/settings) |
 | `skills/change` | `emit` | [`packages/skill/skill/src/index.ts:188`](../packages/skill/skill/src/index.ts) | [`skill`](../packages/skill/skill) (`events.dispatch`) | - |
@@ -428,9 +428,6 @@ flowchart TD
  pkg_compact --> pkg_invariants
  pkg_compact --> pkg_llm
  pkg_compact --> pkg_session
-  pkg_compact_tool_result_prune --> pkg_invariants
-  pkg_compact_tool_result_prune --> pkg_llm
-  pkg_compact_tool_result_prune --> pkg_session
  pkg_web_fetch_local --> pkg_invariants
  pkg_web_fetch_local --> pkg_timeout
  pkg_web_fetch_local --> pkg_web
@@ -490,6 +487,7 @@ flowchart TD
  pkg_llm_retry --> pkg_llm
  pkg_llm_retry --> pkg_session
  pkg_llm_retry --> pkg_timeout
+  pkg_token_meter --> pkg_compact
  pkg_token_meter --> pkg_invariants
  pkg_token_meter --> pkg_llm
  pkg_token_meter --> pkg_session
@@ -626,13 +624,11 @@ flowchart TD
  pkg_command_compact --> pkg_commands
  pkg_command_compact --> pkg_compact
  pkg_command_compact --> pkg_invariants
-  pkg_compact_basic --> pkg_agent
-  pkg_compact_basic --> pkg_compact
-  pkg_compact_basic --> pkg_compact_tool_result_prune
-  pkg_compact_basic --> pkg_invariants
-  pkg_compact_basic --> pkg_llm
-  pkg_compact_basic --> pkg_session
-  pkg_compact_basic --> pkg_token_meter
+  pkg_compact_tool_result_prune --> pkg_compact
+  pkg_compact_tool_result_prune --> pkg_invariants
+  pkg_compact_tool_result_prune --> pkg_llm
+  pkg_compact_tool_result_prune --> pkg_session
+  pkg_compact_tool_result_prune --> pkg_token_meter
  pkg_session_query --> pkg_brand
  pkg_session_query --> pkg_invariants
  pkg_session_query --> pkg_llm
@@ -728,6 +724,13 @@ flowchart TD
  pkg_tool_skill --> pkg_llm
  pkg_tool_skill --> pkg_skill
  pkg_tool_skill --> pkg_tools
+  pkg_compact_basic --> pkg_agent
+  pkg_compact_basic --> pkg_compact
+  pkg_compact_basic --> pkg_compact_tool_result_prune
+  pkg_compact_basic --> pkg_invariants
+  pkg_compact_basic --> pkg_llm
+  pkg_compact_basic --> pkg_session
+  pkg_compact_basic --> pkg_token_meter
  pkg_subagent --> pkg_agent
  pkg_subagent --> pkg_brand
  pkg_subagent --> pkg_invariants
@@ -1138,7 +1141,6 @@ flowchart TD
 | [`bash`](../packages/bash/bash) | `bash` | [`invariants`](../packages/support/invariants), [`sandbox`](../packages/sandbox/sandbox), [`subprocess`](../packages/subprocess/subprocess) |
 | [`fs`](../packages/fs/fs) | `fs` | [`brand`](../packages/util/brand), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`sandbox`](../packages/sandbox/sandbox) |
 | [`compact`](../packages/compact/compact) | `compact` | [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`session`](../packages/core/session) |
-| [`compact-tool-result-prune`](../packages/compact/compact-tool-result-prune) | `compact` | [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`session`](../packages/core/session) |
 | [`web-fetch-local`](../packages/web/web-fetch-local) | `web` | [`invariants`](../packages/support/invariants), [`timeout`](../packages/util/timeout), [`web`](../packages/web/web) |
 | [`web-search-exa`](../packages/web/web-search-exa) | `web` | [`invariants`](../packages/support/invariants), [`web`](../packages/web/web) |
 | [`web-search-perplexity`](../packages/web/web-search-perplexity) | `web` | [`invariants`](../packages/support/invariants), [`web`](../packages/web/web) |
@@ -1155,7 +1157,7 @@ flowchart TD
 | [`sandbox-local`](../packages/sandbox/sandbox-local) | `sandbox` | [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`sandbox`](../packages/sandbox/sandbox) |
 | [`session-projection`](../packages/session-projection/session-projection) | `session-projection` | [`invariants`](../packages/support/invariants), [`session`](../packages/core/session) |
 | [`llm-retry`](../packages/llm/llm-retry) | `llm` | [`agent`](../packages/core/agent), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`session`](../packages/core/session), [`timeout`](../packages/util/timeout) |
-| [`token-meter`](../packages/llm/token-meter) | `llm` | [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`session`](../packages/core/session), [`session-projection`](../packages/session-projection/session-projection) |
+| [`token-meter`](../packages/llm/token-meter) | `llm` | [`compact`](../packages/compact/compact), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`session`](../packages/core/session), [`session-projection`](../packages/session-projection/session-projection) |
 | [`goal`](../packages/goal/goal) | `goal` | [`agent`](../packages/core/agent), [`brand`](../packages/util/brand), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`scope`](../packages/core/scope), [`session`](../packages/core/session), [`session-projection`](../packages/session-projection/session-projection) |
 | [`bash-local`](../packages/bash/bash-local) | `bash` | [`bash`](../packages/bash/bash), [`invariants`](../packages/support/invariants), [`subprocess`](../packages/subprocess/subprocess), [`timeout`](../packages/util/timeout) |
 | [`pwsh-local`](../packages/bash/pwsh-local) | `bash` | [`bash`](../packages/bash/bash), [`invariants`](../packages/support/invariants), [`subprocess`](../packages/subprocess/subprocess), [`timeout`](../packages/util/timeout) |
@@ -1188,7 +1190,7 @@ flowchart TD
 | [`bash-sandbox`](../packages/bash/bash-sandbox) | `bash` | [`bash`](../packages/bash/bash), [`bash-local`](../packages/bash/bash-local), [`invariants`](../packages/support/invariants), [`sandbox`](../packages/sandbox/sandbox), [`sandbox-policy`](../packages/sandbox/sandbox-policy) |
 | [`fs-sandbox`](../packages/fs/fs-sandbox) | `fs` | [`fs`](../packages/fs/fs), [`fs-local`](../packages/fs/fs-local), [`invariants`](../packages/support/invariants), [`sandbox`](../packages/sandbox/sandbox), [`sandbox-policy`](../packages/sandbox/sandbox-policy) |
 | [`command-compact`](../packages/compact/command-compact) | `compact` | [`commands`](../packages/ui/commands), [`compact`](../packages/compact/compact), [`invariants`](../packages/support/invariants) |
-| [`compact-basic`](../packages/compact/compact-basic) | `compact` | [`agent`](../packages/core/agent), [`compact`](../packages/compact/compact), [`compact-tool-result-prune`](../packages/compact/compact-tool-result-prune), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`session`](../packages/core/session), [`token-meter`](../packages/llm/token-meter) |
+| [`compact-tool-result-prune`](../packages/compact/compact-tool-result-prune) | `compact` | [`compact`](../packages/compact/compact), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`session`](../packages/core/session), [`token-meter`](../packages/llm/token-meter) |
 | [`session-query`](../packages/session-query/session-query) | `session-query` | [`brand`](../packages/util/brand), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`session`](../packages/core/session), [`session-persistence`](../packages/session-persistence/session-persistence), [`session-title`](../packages/session-title/session-title) |
 | [`session-title-llm`](../packages/session-title/session-title-llm) | `session-title` | [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`session`](../packages/core/session), [`session-title`](../packages/session-title/session-title), [`timeout`](../packages/util/timeout) |
 | [`acp`](../packages/acp/acp) | `acp` | [`agent`](../packages/core/agent), [`invariants`](../packages/support/invariants), [`session`](../packages/core/session), [`user-approval`](../packages/ui/user-approval) |
@@ -1204,6 +1206,7 @@ flowchart TD
 | [`tool-fs-search`](../packages/fs/tool-fs-search) | `fs` | [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`retention`](../packages/util/retention), [`session`](../packages/core/session), [`spill`](../packages/spill/spill), [`subprocess`](../packages/subprocess/subprocess), [`system-prompt`](../packages/core/system-prompt), [`tools`](../packages/core/tools) |
 | [`tool-str-replace-editor`](../packages/fs/tool-str-replace-editor) | `fs` | [`fs`](../packages/fs/fs), [`invariants`](../packages/support/invariants), [`sandbox`](../packages/sandbox/sandbox), [`sandbox-policy`](../packages/sandbox/sandbox-policy), [`tools`](../packages/core/tools) |
 | [`tool-skill`](../packages/skill/tool-skill) | `skill` | [`agent`](../packages/core/agent), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`skill`](../packages/skill/skill), [`tools`](../packages/core/tools) |
+| [`compact-basic`](../packages/compact/compact-basic) | `compact` | [`agent`](../packages/core/agent), [`compact`](../packages/compact/compact), [`compact-tool-result-prune`](../packages/compact/compact-tool-result-prune), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`session`](../packages/core/session), [`token-meter`](../packages/llm/token-meter) |
 | [`subagent`](../packages/subagent/subagent) | `subagent` | [`agent`](../packages/core/agent), [`brand`](../packages/util/brand), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`scope`](../packages/core/scope), [`session`](../packages/core/session), [`session-persistence`](../packages/session-persistence/session-persistence), [`session-projection`](../packages/session-projection/session-projection), [`session-query`](../packages/session-query/session-query), [`tasks`](../packages/tasks/tasks), [`tools`](../packages/core/tools) |
 | [`tool-web`](../packages/web/tool-web) | `web` | [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`system-prompt`](../packages/core/system-prompt), [`tools`](../packages/core/tools), [`web`](../packages/web/web) |
 | [`spill-policy`](../packages/spill/spill-policy) | `spill` | [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`retention`](../packages/util/retention), [`session`](../packages/core/session), [`spill`](../packages/spill/spill), [`tools`](../packages/core/tools) |
@@ -77,7 +77,7 @@ export type SessionEvent<T extends SessionEventType = SessionEventType> = {
 }[T]
 ```

-Sources: [`packages/core/session/src/types.ts:290`](../packages/core/session/src/types.ts) · [`packages/core/session/src/types.ts:297`](../packages/core/session/src/types.ts) · [`packages/core/session/src/types.ts:325`](../packages/core/session/src/types.ts) · [`packages/core/session/src/types.ts:357`](../packages/core/session/src/types.ts)
+Sources: [`packages/core/session/src/types.ts:308`](../packages/core/session/src/types.ts) · [`packages/core/session/src/types.ts:315`](../packages/core/session/src/types.ts) · [`packages/core/session/src/types.ts:343`](../packages/core/session/src/types.ts) · [`packages/core/session/src/types.ts:375`](../packages/core/session/src/types.ts)

 ## Events

@@ -174,7 +174,7 @@ Source: [`packages/ui/user-approval/src/index.ts:67`](../packages/ui/user-approv

 Types: [StreamChunk](core-data-structures/llm-streaming.md)

-Source: [`packages/core/session/src/types.ts:220`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:238`](../packages/core/session/src/types.ts)

 #### `assistant/message` — surface

@@ -190,7 +190,7 @@ Source: [`packages/core/session/src/types.ts:220`](../packages/core/session/src/

 Types: [TokenUsage](core-data-structures/llm-streaming.md)

-Source: [`packages/core/session/src/types.ts:227`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:245`](../packages/core/session/src/types.ts)

 ### `command/*`

@@ -236,7 +236,31 @@ Source: [`packages/ui/commands/src/index.ts:132`](../packages/ui/commands/src/in
 'compact/end': { turn: number | null; error?: string }
 ```

-Source: [`packages/compact/compact/src/types.ts:51`](../packages/compact/compact/src/types.ts)
+Source: [`packages/compact/compact/src/types.ts:54`](../packages/compact/compact/src/types.ts)
+
+#### `compact/prune` — log-only
+
+```ts persistence-catalog
+/**
+ * Shadow price of one model-free prune replacement — log-only, no
+ * surfaceOp. The shared shadow-price protocol: a surface `replace` event
+ * is priced by the metering event immediately before it (`compact/summary`
+ * for a summarizing compaction, this event for a prune), which states the
+ * heuristic token price of the exact replaced range so a pure consumer
+ * can subtract it without retaining per-node prices. The replacement MUST
+ * be appended synchronously right after this event.
+ */
+'compact/prune': {
+  /** The replaced range's first and last surface-node seqs (a surface-position span, like {@link CompactionResult.shadowedRange}). */
+  shadowedRange: { start: number; end: number }
+  /** The seqs of all shadowed surface nodes, in surface order. */
+  shadowedSeqs: number[]
+  /** Heuristic price of the shadowed content under the token-meter's fixed estimator. */
+  shadowedTokenCount: number
+}
+```
+
+Source: [`packages/compact/compact/src/types.ts:64`](../packages/compact/compact/src/types.ts)

 #### `compact/start` — log-only

@@ -257,8 +281,11 @@ Source: [`packages/compact/compact/src/types.ts:19`](../packages/compact/compact
 /**
 * Provenance record of a completed summarization — log-only, no surfaceOp.
 * The summary content is in `data.summary`; the actual surface replacement
- * is performed by a subsequent `user/message` event that shadows the
- * compacted range.
+ * is performed by the immediately following `user/message` event that
+ * shadows the compacted range. That adjacency is contractual — the
+ * shadowed pricing fields are the replacement's shadow price, so a
+ * consumer may pair a replacement with the metering event directly
+ * before it (`compact/prune` documents the shared protocol).
 */
 'compact/summary': {
  summary: ContentBlock[]
@@ -285,7 +312,7 @@ Source: [`packages/compact/compact/src/types.ts:19`](../packages/compact/compact

 Types: [ContentBlock](core-data-structures/core.md) · [TokenUsage](core-data-structures/llm-streaming.md)

-Source: [`packages/compact/compact/src/types.ts:26`](../packages/compact/compact/src/types.ts)
+Source: [`packages/compact/compact/src/types.ts:29`](../packages/compact/compact/src/types.ts)

 ### `goal/*`

@@ -419,7 +446,7 @@ Source: [`packages/plan/plan-mode/src/index.ts:52`](../packages/plan/plan-mode/s
 'request/context': RequestContext
 ```

-Source: [`packages/core/session/src/types.ts:263`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:281`](../packages/core/session/src/types.ts)

 #### `request/header` — log-only

@@ -431,7 +458,7 @@ Source: [`packages/core/session/src/types.ts:263`](../packages/core/session/src/
 'request/header': { header: EpochHeader; reason: RequestHeaderReason }
 ```

-Source: [`packages/core/session/src/types.ts:258`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:276`](../packages/core/session/src/types.ts)

 ### `sandbox/*`

@@ -484,7 +511,7 @@ Source: [`packages/sandbox/sandbox-policy/src/session-mode.ts:33`](../packages/s
 'session/end-seed': Record<string, never>
 ```

-Source: [`packages/core/session/src/types.ts:286`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:304`](../packages/core/session/src/types.ts)

 #### `session/title` — log-only

@@ -520,7 +547,7 @@ Source: [`packages/session-title/session-title-llm/src/index.ts:43`](../packages
 'step/end': { turn: number; step: number }
 ```

-Source: [`packages/core/session/src/types.ts:210`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:228`](../packages/core/session/src/types.ts)

 #### `step/start` — log-only

@@ -529,7 +556,7 @@ Source: [`packages/core/session/src/types.ts:210`](../packages/core/session/src/
 'step/start': { turn: number; step: number }
 ```

-Source: [`packages/core/session/src/types.ts:208`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:226`](../packages/core/session/src/types.ts)

 ### `subagent/*`

@@ -559,7 +586,7 @@ Source: [`packages/subagent/subagent/src/descriptor.ts:37`](../packages/subagent

 Types: [TodoItem](core-data-structures/session.md)

-Source: [`packages/core/session/src/types.ts:253`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:271`](../packages/core/session/src/types.ts)

 ### `tool/*`

@@ -576,7 +603,7 @@ Source: [`packages/core/session/src/types.ts:253`](../packages/core/session/src/

 Types: [CallId](core-data-structures/core.md)

-Source: [`packages/core/session/src/types.ts:233`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:251`](../packages/core/session/src/types.ts)

 #### `tool/code-dispatch` — log-only

@@ -649,7 +676,7 @@ Source: [`packages/core/tools/src/code-mode.ts:33`](../packages/core/tools/src/c
 }
 ```

-Source: [`packages/core/session/src/types.ts:245`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:263`](../packages/core/session/src/types.ts)

 ### `turn/*`

@@ -669,7 +696,7 @@ Source: [`packages/core/session/src/types.ts:245`](../packages/core/session/src/

 Types: [TurnEndReason](core-data-structures/session.md)

-Source: [`packages/core/session/src/types.ts:206`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:224`](../packages/core/session/src/types.ts)

 #### `turn/start` — log-only

@@ -683,7 +710,7 @@ Source: [`packages/core/session/src/types.ts:206`](../packages/core/session/src/
 'turn/start': { turn: number }
 ```

-Source: [`packages/core/session/src/types.ts:197`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:215`](../packages/core/session/src/types.ts)

 ### `user/*`

@@ -700,7 +727,7 @@ Source: [`packages/core/session/src/types.ts:197`](../packages/core/session/src/
 'user/message': UserMessage
 ```

-Source: [`packages/core/session/src/types.ts:218`](../packages/core/session/src/types.ts)
+Source: [`packages/core/session/src/types.ts:236`](../packages/core/session/src/types.ts)

 ### `web/*`

@@ -88,7 +88,7 @@ Bringing up a new `packages/client/<name>` plugin package (ui-workspace is the l
 1. **Package skeleton**: `package.json` (`@deepseek-ai/dsh-client-<name>`, exports `.`/`./invariant`/`./client`/`./src/*`/`./package.json`, `dshClient` manifest, `files` list), `tsconfig.json` (extends `tsconfig.base.client.json`, one `references` entry per workspace dependency plus `support/invariants`), `tsdown.config.ts` (`clientBundle(id, ['lib/types/index.js', 'lib/types/invariant.js'])`), `src/index.ts` (empty node-half apply), `src/invariant.ts` (companion with a real reason), `src/css-modules.d.ts` when using CSS Modules, `README.md` with the Model Experience section.
 2. **Three registration surfaces, all required** (missing any one fails at a different, later point): the `tsconfig.client.json` aggregate `references` entry; a `dshClient` row in `apps/cli/config/web.cordis.yml`; an `apps/cli/package.json` dependency (Loader resolves each config-tree package against the composing app's URL — a row whose package is not an `apps/cli` dependency fails to import). `pnpm-workspace.yaml` already globs `packages/*/*`.
 3. **dshClient manifest semantics**: `platform: 'web'` always; `immediately: true` only for stage-one-prefetch infrastructure rows. `inject` lists package-name dependency edges — they are **informational only** (preflight display, HMR diffing); they do not sequence entry activation or apply order. Activation order is cordis fiber inject waiting on *services*, nothing else.
-4. **Registering into another package's slot**: if the declaring host provides no waitable service, your apply's order relative to the host's is unconstrained — a bare `slots.register` into its slot races boot (intermittent `slot "..." is not declared` page failures). Register with declaration-aware deferral: check `ctx.slots.spec(name)`, otherwise `ctx.slots.subscribe(name)` and register on the declaration event (SlotCore supports subscribing ahead of declaration); make the registration idempotent, and unsubscribe + dispose in the effect disposer. Only take a service edge in `inject` when the host actually provides one (ui-question → `'conversation'` is that case).
+4. **Registering into another package's slot**: apply order is unconstrained, and a business service is not a declaration barrier. Use `ctx.slots.inject(name, () => ctx.slots.register(...))`; it waits on the actual declaration, removes the contribution when that declaration collapses, reruns after redeclaration, and leaves with the caller's plugin fiber. Return a generator yielding each registration when several contributions must install and roll back atomically. A bare `slots.register` into an undeclared slot remains an error; keep service edges only for services the contribution actually reads.
 5. Rebuild the bundle (`pnpm --filter <pkg> bundle`) before probing a live `dsh web` server — the registry serves `lib/client.js`, not sources.

 ## New component checklist
@@ -27,7 +27,7 @@ import type {
 // Type-only: the brand constructor is host-side; the fixture casts at its
 // wire-fabrication boundary (the schema layer's one-cast-point posture).
 import type { CommandId } from '@deepseek-ai/dsh-commands/brand'
-import { foldSurface } from '@deepseek-ai/dsh-session/surface'
+import { deriveEventMessage, foldSurface } from '@deepseek-ai/dsh-session/surface'
 import type {
  ApiProxy, ClientRequest, ClientResponse, HistoryEntry, HostFrame, MuxFrame, RpcReceipt,
  ModelProviderGroup, ModelTarget, RpcRequest, RpcResponse, RpcResult, ServerRequest, ServerResponse, SessionSummary,
@@ -167,7 +167,7 @@ const SEARCH_MATCHES_FIXTURE: { path: string; matches: { lineNumber: number; lin
      { lineNumber: 33, line: 'export function SearchRow({ toolName, block, inspect, t }: SearchRowProps) {' },
      { lineNumber: 35, line: '  const search = searchCardModel(block)' },
      { lineNumber: 52, line: '      search={search}' },
-      { lineNumber: 73, line: "    ctx.slots.register({ name: 'conversation.chat.toolview', key: 'grep', locale: NS }, SearchRow)" },
+      { lineNumber: 78, line: "      yield ctx.slots.register({ name: 'conversation.chat.toolview', key: 'grep', locale: NS }, SearchRow)" },
    ],
  },
 ]
@@ -358,6 +358,12 @@ function buildAlphaLog(): SessionEvent[] {
    events.push({ seq, time: (time += 800), ...authored })
    return seq
  }
+  // This resident history represents completed model requests, so retain the
+  // route capacity that accompanied them just as the live prompt path does.
+  push({
+    type: 'request/context',
+    data: { provider: 'deepseek-official', model: 'deepseek-v4-flash', contextWindow: 128_000 },
+  })
  for (let turn = 0; turn < 60; turn++) {
    push({ type: 'turn/start', data: { turn } })
    const userSeq = push({
@@ -819,6 +825,62 @@ interface FixtureRequestContext {
  contextWindow?: number
 }

+interface FixtureContextBreakdownProjection {
+  systemTokens: number
+  toolsTokens: number
+  messageTokens: number
+}
+
+/** Fixed token-meter heuristic constants mirrored by this client-only fixture. */
+const CHARS_PER_TOKEN = 4
+const BLOCK_OVERHEAD = 4
+const ROLE_OVERHEAD = 4
+
+/** Price fixture content with token-meter's fixed-density heuristic. */
+function estimateFixtureContent(blocks: readonly ContentBlock[]): number {
+  const densityPrice = (value: string): number => Math.ceil(value.length / CHARS_PER_TOKEN)
+  return blocks.reduce((tokens, block) => {
+    if (block.type === 'text' || block.type === 'reasoning') {
+      return tokens + densityPrice(block.text) + BLOCK_OVERHEAD
+    }
+    if (block.type === 'tool-call') {
+      return tokens + densityPrice(block.name) + densityPrice(block.arguments) + BLOCK_OVERHEAD
+    }
+    // ContentBlockMap is merge-extensible: this client graph sees only the
+    // base four members, but fixture turns do carry extended blocks at
+    // runtime, so the structural JSON fallback below is live code.
+    // oxlint-disable-next-line typescript/no-unnecessary-condition -- the type collapses without the out-of-graph merges (see above).
+    if (block.type === 'tool-result') {
+      return tokens + estimateFixtureContent(block.content) + BLOCK_OVERHEAD
+    }
+    return tokens + densityPrice(JSON.stringify(block)) + BLOCK_OVERHEAD
+  }, 0)
+}
+
+/** Fixture parallel of token-meter's heuristic context-composition projection. */
+function contextBreakdownOf(log: readonly SessionEvent[]): FixtureContextBreakdownProjection {
+  const headerEvent = log.findLast(event => event.type === 'request/header')
+  const header = headerEvent === undefined
+    ? undefined
+    : headerEvent.data.header
+  let messageTokens = 0
+  for (const seq of foldSurface(log).nodes) {
+    const event = log[seq]
+    if (event === undefined) continue
+    const message = deriveEventMessage(event)
+    if (message !== null) messageTokens += estimateFixtureContent(message.content) + ROLE_OVERHEAD
+  }
+  return {
+    systemTokens: header?.system === undefined
+      ? 0
+      : Math.ceil(header.system.length / CHARS_PER_TOKEN) + ROLE_OVERHEAD,
+    toolsTokens: header?.tools === undefined || header.tools.length === 0
+      ? 0
+      : Math.ceil(JSON.stringify(header.tools).length / CHARS_PER_TOKEN) + BLOCK_OVERHEAD,
+    messageTokens,
+  }
+}
+
 /** Latest log-only route context, or undefined before any request ran. */
 function lastRequestContext(
  log: readonly SessionEvent[],
@@ -832,7 +894,11 @@ function lastRequestContext(
 /**
 * Fixture parallel of token-meter's request-pressure projection: the last
 * provider-reported prompt size paired with the last recorded capacity. The
- * two need not come from one request — see the token-meter README.
+ * two need not come from one request — see the token-meter README. The host's
+ * `projectedTokens` is deliberately absent: reproducing it would mean
+ * reimplementing the estimator client-side, and every consumer falls back to
+ * the bare sample, so a fixture-driven view simply lags a compaction the way
+ * the projection did before that field existed.
 */
 function contextPressureOf(
  log: readonly SessionEvent[],
@@ -870,28 +936,44 @@ function projectionValuesOf(log: readonly SessionEvent[]): Record<string, unknow
  values['tokenUsage'] = tokenUsageOf(log)
  // Always present (token-meter composed): last request pressure and capacity.
  values['contextPressure'] = contextPressureOf(log)
+  // Always present (token-meter composed): heuristic request composition.
+  values['contextBreakdown'] = contextBreakdownOf(log)
  return values
 }

 /** Host push-frame parallel: emit one session/projection frame per key the given event advanced. */
 function projectionFramesOf(id: SessionId, log: readonly SessionEvent[], event: SessionEvent): Extract<MuxFrame, { type: 'session/projection' }>[] {
  const type = (event as { type: string }).type
+  const frames: Extract<MuxFrame, { type: 'session/projection' }>[] = []
  // One usage sample advances both token-meter units.
  if (usageSampleOf(event) !== undefined) {
-    return [
+    frames.push(
      { type: 'session/projection', sessionId: id, key: 'tokenUsage', value: tokenUsageOf(log), seq: event.seq },
      { type: 'session/projection', sessionId: id, key: 'contextPressure', value: contextPressureOf(log), seq: event.seq },
-    ]
+    )
  }
  if (type === 'request/context') {
-    return [{
+    frames.push({
      type: 'session/projection',
      sessionId: id,
      key: 'contextPressure',
      value: contextPressureOf(log),
      seq: event.seq,
-    }]
+    })
  }
+  if (type === 'request/header'
+    || type === 'user/message'
+    || type === 'assistant/message'
+    || type === 'tool/result') {
+    frames.push({
+      type: 'session/projection',
+      sessionId: id,
+      key: 'contextBreakdown',
+      value: contextBreakdownOf(log),
+      seq: event.seq,
+    })
+  }
+  if (frames.length > 0) return frames
  if (type === 'session/title') {
    const values = projectionValuesOf(log)
    /* v8 ignore next -- the advancing title event is in the log, so the key is present. */
@@ -159,6 +159,11 @@ describe('createFixtureApi', () => {
        },
        // No request ran, so neither pressure nor capacity is known yet.
        contextPressure: {},
+        contextBreakdown: {
+          systemTokens: 0,
+          toolsTokens: 0,
+          messageTokens: 0,
+        },
      } },
    })
  })
@@ -304,6 +309,10 @@ describe('createFixtureApi', () => {
      frame.type === 'session/projection'
      && frame.key === 'contextPressure'
      && (frame.value as { contextWindow?: number }).contextWindow === 128_000)).toBe(true)
+    expect(frames.some(frame =>
+      frame.type === 'session/projection'
+      && frame.key === 'contextBreakdown'
+      && (frame.value as { messageTokens?: number }).messageTokens! > 0)).toBe(true)
    const finalize = frames.find((f): f is Extract<MuxFrame, { type: 'session/event' }> => f.type === 'session/event' && f.event.type === 'assistant/message')
    expect(JSON.stringify(finalize?.event.data)).toContain('（已中断）')
    // Idle cancel: no replay in flight, must not explode; running flips false.
@@ -335,7 +344,7 @@ describe('createFixtureApi', () => {
      const envelopes: RpcRequest<MuxFrame>[] = []
      for await (const envelope of api.events.mux(req({}), abort.signal)) {
        envelopes.push(envelope)
-        if (envelopes.length >= 10) abort.abort()
+        if (envelopes.length >= 11) abort.abort()
      }
      return envelopes
    }
@@ -351,10 +360,15 @@ describe('createFixtureApi', () => {
    expect(first[5]?.payload).toMatchObject({ type: 'session/projection', sessionId: 'fx-alpha', key: 'goal', value: null })
    expect(first[6]?.payload).toMatchObject({ type: 'session/projection', sessionId: 'fx-alpha', key: 'tokenUsage' })
    expect(first[7]?.payload).toMatchObject({ type: 'session/projection', sessionId: 'fx-alpha', key: 'contextPressure' })
-    expect(first[8]?.payload).toMatchObject({ type: 'approval/requested', toolName: 'dangerous_tool' })
-    expect(second[8]?.rpcId).toBe(first[8]?.rpcId) // stable rpcId across replays (host replay semantics)
-    expect(first[9]?.payload).toMatchObject({ type: 'question/requested', sessionId: 'fx-alpha' })
-    expect(second[9]?.rpcId).toBe(first[9]?.rpcId)
+    expect(first[8]?.payload).toMatchObject({
+      type: 'session/projection', sessionId: 'fx-alpha', key: 'contextBreakdown',
+      value: { systemTokens: 0, toolsTokens: 0 },
+    })
+    expect((first[8]?.payload as { value: { messageTokens: number } }).value.messageTokens).toBeGreaterThan(0)
+    expect(first[9]?.payload).toMatchObject({ type: 'approval/requested', toolName: 'dangerous_tool' })
+    expect(second[9]?.rpcId).toBe(first[9]?.rpcId) // stable rpcId across replays (host replay semantics)
+    expect(first[10]?.payload).toMatchObject({ type: 'question/requested', sessionId: 'fx-alpha' })
+    expect(second[10]?.rpcId).toBe(first[10]?.rpcId)
  })

  it('steer with no replay in flight falls through to a fresh queued turn; non-text blocks stringify empty', async () => {
@@ -11,7 +11,6 @@
 * string-typed. The rule fires on the narrow-map view, not real redundancy. */
 import type { Context } from 'cordis'
 import {
-  deferRegistration,
  type BoundActions, type LocaleDictOf, type LocaleNamespaceMap, type Translate, type TranslateNS,
 } from '@deepseek-ai/dsh-client-ui-slots'
 import type { ClientContext } from '@deepseek-ai/dsh-client-runtime/client'
@@ -384,16 +383,12 @@ export function apply(ctx: ClientContext): void {
      setLocale: (id) => { locale.setLocale(id) },
    }
  }
-  ctx.effect(() => {
-    const deferred = deferRegistration(ctx.slots, 'settings.general.item', LanguageRow, () =>
-      ctx.slots.register({
-        name: 'settings.general.item',
-        id: 'language',
-        order: 0,
-        store,
-        locale: SETTINGS_NS,
-        inject: injected,
-      }, LanguageRow))
-    return () => { deferred.dispose() }
-  }, 'locale: language settings row registration')
+  ctx.slots.inject('settings.general.item', () => ctx.slots.register({
+    name: 'settings.general.item',
+    id: 'language',
+    order: 0,
+    store,
+    locale: SETTINGS_NS,
+    inject: injected,
+  }, LanguageRow))
 }
@@ -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: b390c2830a47ed380e01bc7ec763b4bd8d8459e8
-README.zh.md: 0aaad0b7620394f151b6a757f924d22d4f2140ab
+README.md: f95e06162bca132a9aa83e0b84e875a81d2f8fc6
+README.zh.md: 4b1a9dda3bbe02ef9241a8a797a07e5285e6daae
@@ -4,6 +4,12 @@ English | [中文](README.zh.md)

 Client cordis boot and React-free object services: SlotsService wraps SlotCore and supplies renderer data sources; SessionsService owns Session objects and the Chat-facing list, scope, and event-window state; SessionHistoryService lazily owns independent raw-history ledgers for inspection consumers, loading the current tail first and prepending one older page only when its consumer requests it. Each history snapshot exposes the raw window's absolute base sequence so a consumer detects a prepend even when the page adds no surface-visible node. WorkspacesService depends on SessionsService and owns Workspace objects, list/actions, default-target derivation, and the New Session blank-reuse entry (`connectWorkspace`). The runtime fans the shared Host stream into the Session, Workspace, and activated history owners without routing inspection state through Session or SessionManager, and bridges the registry-invalidation frames to typed ctx events (`commands/changed`, `settings/changed`, `credentials/changed`, `models/changed`) so surface caches refetch without touching the stream. Client sessions are always Host-born (Session+Agent+cwd in one `session.create`); the client holds no pre-entity session state — a session's Agent scope (the client mirror of host dsh-scope, keyed by the shared agent/session id) is born when its row enters the list mirror and dies with the prune. Contract: api-contracts v3 §4. Each `Session` holds a generic `ProjectionValueStore` seeded from the history-tail `projections` block and updated by `session/projection` frames under higher-seq-wins; domain keys (including `todos`) are read via `projections.faceOf` / `useProjection`, not via `ConversationSnapshot`. The store also publishes one reference-stable whole-value map through `SessionSummary.projectionValues`, allowing global list consumers to reuse the same projections without creating per-session subscriptions.

+## Slot declaration injection
+
+`ctx.slots.inject(name, callback)` makes a full `SlotMap` key the dependency for a contribution whose plugin can activate independently from the declaring entry. It runs `callback` synchronously when the declaration exists, otherwise waits; declaration collapse disposes the callback effect, and redeclaration reruns it. The controller belongs to the caller's plugin fiber, so unloading the contributor cancels either the wait or its active registrations. A direct `slots.register()` into an undeclared slot still throws.
+
+The callback returns one synchronous disposer or an iterable of disposers. A generator can therefore yield several `slots.register()` calls as one transaction: setup failure rolls earlier yields back and teardown runs them in reverse order. Declaration lifetimes use a dedicated monotonic epoch, so a collapse and redeclaration batched into one renderer notification still restarts the callback, while ordinary entry changes do not. Declaration-bound teardown runs synchronously with the ledger mutation, releasing runtime resources before subsequent same-tick registrations. See the [declaration-injection decision](../../../.agents/notes/implemented/architecture/2026-08-05-slot-declaration-injection.md).
+
 ## Workspace and Session lists

 Workspace and Session lists have independent monotone `pending` → `ready` baseline phases and separate refresh activity/error state. Incremental upsert/removal frames and unary mutation echoes arriving during a list request replay over its response. The first successful baseline establishes Host order; later refreshes update rows and membership without changing the relative order of identities already shown. Removed Workspace ids retain process-local tombstones so late changed frames cannot resurrect them; reconnect still takes `workspace.list` as the baseline. Workspace recency is derived only after both baselines are ready and never changes Workspace list order.
@@ -4,6 +4,12 @@

 客户端 cordis 启动与不依赖 React 的对象服务：SlotsService 包装 SlotCore 并提供 renderer 数据源；SessionsService 拥有 Session 对象以及 Chat 所需的列表、scope 和事件窗口状态；SessionHistoryService 为检查类消费方惰性拥有彼此独立的原始历史账本，先加载当前尾部，并仅在消费方请求时向前补入一页更早历史。每份历史快照都会公开原始窗口的绝对基准序号，因此即使该页没有新增任何 surface 可见节点，消费方仍能检测到向前补页。WorkspacesService 依赖 SessionsService，拥有 Workspace 对象、列表／操作、默认目标派生，以及 New Session 空会话复用入口（`connectWorkspace`）。运行时把共享 Host 流分发给 Session、Workspace 和已激活的历史数据所有者，不让检查状态经过 Session 或 SessionManager，并把注册表失效帧桥接为类型化 ctx 事件（`commands/changed`、`settings/changed`、`credentials/changed`、`models/changed`），使各表面缓存无需触碰流即可重拉。客户端会话一律由 Host 创建（一次 `session.create` 同时产生 Session、agent（智能体）和 cwd）；客户端不持有任何实体化之前的会话状态——agent scope（host dsh-scope 的客户端镜像，以 agent/session 共用 id 为键）在会话行进入列表镜像时创建，并随 prune 销毁。契约：api-contracts v3 §4。每个 `Session` 持有一个通用的 `ProjectionValueStore`，由历史记录尾部的 `projections` 块播种，并经 `session/projection` 帧按 seq 高者胜更新；领域键（含 `todos`）经 `projections.faceOf`／`useProjection` 读取，不经 `ConversationSnapshot`。该 store 还会通过 `SessionSummary.projectionValues` 发布一份引用稳定的完整值映射，使全局列表消费方无需为每个会话创建订阅，即可复用同一组投影。

+## Slot 声明注入
+
+`ctx.slots.inject(name, callback)` 将完整的 `SlotMap` key 作为贡献项的依赖，适用于贡献方插件可独立于声明条目激活的情形。声明存在时，它会同步运行 `callback`，否则等待；声明折叠会 dispose（资源释放）回调 effect，重新声明则会再次运行回调。控制器归调用方的插件 fiber 所有，因此卸载贡献方会取消等待或移除其活跃注册项。直接调用 `slots.register()` 向未声明 slot 注册仍会抛出异常。
+
+回调返回一个同步 disposer 或由多个 disposer 构成的 iterable。因此，generator 可以 yield 多个 `slots.register()` 调用，并将它们组成一项事务：setup 失败会回滚先前 yield 的 effect，teardown 则按逆序运行它们。声明生命周期使用专用的单调 declaration epoch（声明代次），因此，即使折叠与重新声明合并在同一次 renderer 通知中，回调仍会重启，而普通条目变更不会重启它。声明绑定的 teardown 与账本变更同步运行，在同一 tick 内的后续注册之前释放运行时资源。详见 [slot 声明注入决策](../../../.agents/notes/implemented/architecture/2026-08-05-slot-declaration-injection.md)。
+
 ## Workspace 与 Session 列表

 Workspace 和 Session 列表各自具有单调的 `pending` → `ready` 基线阶段，也有各自的刷新活动／错误状态。列表请求期间到达的增量插入或更新／移除帧与一元变更回显会在其响应之上回放。第一次成功的基线建立 Host 顺序；后续刷新更新行和成员关系，但不改变已经显示的标识之间的相对顺序。已移除的 Workspace id 会保留进程本地删除标记，避免延迟到达的 changed 帧将其复活；重连仍以 `workspace.list` 作为基线。Workspace 新近程度只在两条基线都 ready 后派生，且绝不改变 Workspace 列表顺序。
@@ -46,7 +52,7 @@ SlotsService 分别为 renderer 提供 `useSessions` 与 `useWorkspaces` 的裸

 ## 模型重试投影

-Session 对象会在事件 wire 边界依据生产方的完整字段契约，验证由插件负责、按提供方路由的 `llm/retry` 载荷，包括计时器、整数、状态、提供方延迟和非空诊断字段的边界。有效事件会移除对应失败步骤的流式输出片段，并在该事件的序列位置插入一条持久的重试提示。该提示在后续重试轮次开始前为 `scheduled`；源轮次中止或被 dispose（资源释放）时，会将该提示标记为 `cancelled`，重试轮次则会将其标记为 `started`。normal mode 提示携带其有限上限；always mode 提示则保持显式无界。没有重试的终态 `turn/end` 错误会从持久消息与可选错误码投影出一个 `turn-error` 节点；AUTH 投影会把可能回显凭据片段的提供方文案替换为 `API key is invalid`，原始诊断仍保留在会话日志中。进入重试的失败则只保留该次尝试的重试提示。窗口重建与历史回放应用相同的投影，因此刷新既不会让已丢弃的分片重新出现，也不会丢失终态失败反馈。可见但尚未定稿的输出会在终态错误旁冻结为中断的 assistant 节点。
+Session 对象会在事件 wire 边界依据生产方的完整字段契约，验证由插件负责、按提供方路由的 `llm/retry` 载荷，包括计时器、整数、状态、提供方延迟和非空诊断字段的边界。有效事件会移除对应失败步骤的流式输出片段，并在该事件的序列位置插入一条持久的重试提示。该提示在后续重试轮次开始前为 `scheduled`；源轮次中止或被 dispose 时，会将该提示标记为 `cancelled`，重试轮次则会将其标记为 `started`。normal mode 提示携带其有限上限；always mode 提示则保持显式无界。没有重试的终态 `turn/end` 错误会从持久消息与可选错误码投影出一个 `turn-error` 节点；AUTH 投影会把可能回显凭据片段的提供方文案替换为 `API key is invalid`，原始诊断仍保留在会话日志中。进入重试的失败则只保留该次尝试的重试提示。窗口重建与历史回放应用相同的投影，因此刷新既不会让已丢弃的分片重新出现，也不会丢失终态失败反馈。可见但尚未定稿的输出会在终态错误旁冻结为中断的 assistant 节点。

 ## 会话 fork

@@ -16,6 +16,8 @@ import type {
 } from '../sessions/conversation-context.ts'
 import type { ConversationPromptSnapshot } from '../sessions/request-inspection.ts'
 import { PartialAccumulator } from '../sessions/partial.ts'
+import type { AssistantStepMetadata } from '../sessions/assistant-timing.ts'
+import { indexAssistantStepTiming, settledAssistantTiming } from '../sessions/assistant-timing.ts'

 interface CallIndexEntry {
  name: string
@@ -30,11 +32,6 @@ interface FoldedContext {
  originSeq?: number
 }

-interface AssistantStepMetadata {
-  stepStartTime: number | null
-  firstTokenTime: number | null
-}
-
 /** Immutable conversation projections derived only from the history source. */
 export interface ConversationHistoryProjection {
  eventNodes: readonly ConversationNode[]
@@ -45,10 +42,6 @@ export interface ConversationHistoryProjection {
  codeDispatches: ReadonlyMap<string, readonly CodeSubCall[]>
 }

-function assistantStepKey(turn: number, step: number): string {
-  return `${turn}\u0000${step}`
-}
-
 function replacementCrossesWindowHead(event: SessionEvent, baseSeq: number): boolean {
  if (!isSurfaceEvent(event) || event.surfaceOp === 'append') return false
  return event.surfaceOp.start < baseSeq || event.surfaceOp.end < baseSeq
@@ -64,21 +57,7 @@ function contextOriginKind(event: SessionEvent | undefined): ConversationContext
  return 'rewrite'
 }

-function isTokenDelta(chunk: SessionEvent<'assistant/chunk'>['data']['chunk']): boolean {
-  switch (chunk.type) {
-    case 'text-delta':
-    case 'reasoning-delta':
-      return chunk.text !== ''
-    case 'tool-call-delta':
-      return chunk.argumentsDelta !== '' || chunk.name !== undefined
-    default:
-      return false
-  }
-}
-
-function foldContexts(
-  events: readonly SessionEvent[],
-): readonly FoldedContext[] {
+function foldContexts(events: readonly SessionEvent[]): readonly FoldedContext[] {
  const replay: SessionEvent[] = []
  const originalSeqs: number[] = []
  const rebasedSeqByOriginal = new Map<number, number>()
@@ -381,6 +360,7 @@ export function projectConversationHistory(
      contextGeneration++
      if (activePrompt !== undefined) promptsByContext.set(contextGeneration, activePrompt)
    }
+    indexAssistantStepTiming(assistantSteps, event)
    if (event.type === 'request/header') {
      activeRequestConfig = event.data.header.config
      activePrompt = {
@@ -389,30 +369,10 @@ export function projectConversationHistory(
        tools: event.data.header.tools ?? [],
      }
      promptsByContext.set(contextGeneration, activePrompt)
-    } else if (event.type === 'step/start') {
-      assistantSteps.set(
-        assistantStepKey(event.data.turn, event.data.step),
-        { stepStartTime: event.time, firstTokenTime: null },
-      )
-    } else if (event.type === 'assistant/chunk' && isTokenDelta(event.data.chunk)) {
-      const key = assistantStepKey(event.data.turn, event.data.step)
-      const current = assistantSteps.get(key) ?? {
-        stepStartTime: null,
-        firstTokenTime: null,
-      }
-      if (current.firstTokenTime === null) {
-        assistantSteps.set(key, { ...current, firstTokenTime: event.time })
-      }
    } else if (event.type === 'assistant/message') {
      assistantTimings.set(
        event.seq,
-        {
-          ...(assistantSteps.get(assistantStepKey(event.data.turn, event.data.step)) ?? {
-            stepStartTime: null,
-            firstTokenTime: null,
-          }),
-          completedTime: event.time,
-        },
+        settledAssistantTiming(assistantSteps, event.data.turn, event.data.step, event.time),
      )
      if (activeRequestConfig !== undefined) {
        assistantRequestConfigs.set(event.seq, activeRequestConfig)
@@ -0,0 +1,84 @@
+// Shared assistant step-timing fold: both transcript projections (the live
+// window adapter and the trajectory history fold) derive AssistantTiming from
+// the same step/start -> first token delta -> assistant/message sequence, so
+// the derivation lives once here instead of drifting per projection.
+
+import type { SessionEvent } from '@deepseek-ai/dsh-session/types'
+import type { AssistantTiming } from './conversation.ts'
+
+/** Pre-finalize timing boundaries for one assistant step (start + first token). */
+export interface AssistantStepMetadata {
+  stepStartTime: number | null
+  firstTokenTime: number | null
+}
+
+/**
+ * Composite map key for one assistant step.
+ * @param turn - turn number from the event payload.
+ * @param step - step number from the event payload.
+ * @returns collision-free `turn`/`step` key (NUL separator).
+ */
+export function assistantStepKey(turn: number, step: number): string {
+  return `${turn}\u0000${step}`
+}
+
+/**
+ * Whether a chunk carries visible model output (first-token boundary). Empty
+ * deltas (heartbeats, empty tool-call frames) do not count as a first token.
+ * @param chunk - the assistant/chunk payload.
+ * @returns true when the chunk contains a non-empty text/reasoning/tool delta.
+ */
+export function isTokenDelta(chunk: SessionEvent<'assistant/chunk'>['data']['chunk']): boolean {
+  switch (chunk.type) {
+    case 'text-delta':
+    case 'reasoning-delta':
+      return chunk.text !== ''
+    case 'tool-call-delta':
+      return chunk.argumentsDelta !== '' || chunk.name !== undefined
+    default:
+      return false
+  }
+}
+
+/**
+ * Fold one event into the per-step timing index: step/start opens the entry,
+ * the first non-empty token delta stamps first-token time once. Other event
+ * types are no-ops.
+ * @param steps - the mutable per-step index, keyed by {@link assistantStepKey}.
+ * @param event - the raw window event.
+ */
+export function indexAssistantStepTiming(steps: Map<string, AssistantStepMetadata>, event: SessionEvent): void {
+  if (event.type === 'step/start') {
+    steps.set(
+      assistantStepKey(event.data.turn, event.data.step),
+      { stepStartTime: event.time, firstTokenTime: null },
+    )
+  } else if (event.type === 'assistant/chunk' && isTokenDelta(event.data.chunk)) {
+    const key = assistantStepKey(event.data.turn, event.data.step)
+    const current = steps.get(key) ?? { stepStartTime: null, firstTokenTime: null }
+    if (current.firstTokenTime === null) {
+      steps.set(key, { ...current, firstTokenTime: event.time })
+    }
+  }
+}
+
+/**
+ * Settle one finalized assistant message's timing from its step entry; a step
+ * whose start or first token fell outside the window yields null boundaries.
+ * @param steps - the per-step index built by {@link indexAssistantStepTiming}.
+ * @param turn - the assistant/message turn number.
+ * @param step - the assistant/message step number.
+ * @param completedTime - the assistant/message event timestamp (epoch ms).
+ * @returns the node-ready timing record.
+ */
+export function settledAssistantTiming(
+  steps: ReadonlyMap<string, AssistantStepMetadata>,
+  turn: number,
+  step: number,
+  completedTime: number,
+): AssistantTiming {
+  return {
+    ...(steps.get(assistantStepKey(turn, step)) ?? { stepStartTime: null, firstTokenTime: null }),
+    completedTime,
+  }
+}
@@ -22,6 +22,8 @@ import type { COMPACT_CHECKPOINT_SOURCE } from '@deepseek-ai/dsh-compact/checkpo
 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'
+import type { AssistantStepMetadata } from './assistant-timing.ts'
+import { indexAssistantStepTiming, settledAssistantTiming } from './assistant-timing.ts'

 /**
 * The compaction seam's checkpoint plugin, pinned to the seam's own declaration
@@ -49,6 +51,7 @@ function materializeNode(
  event: SessionEvent,
  callIndex: ReadonlyMap<string, CallIndexEntry>,
  resultView: ToolResultView | null,
+  stepTimings: ReadonlyMap<string, AssistantStepMetadata>,
 ): ConversationNode {
  switch (event.type) {
    case 'user/message':
@@ -70,6 +73,7 @@ function materializeNode(
        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,
+        timing: settledAssistantTiming(stepTimings, event.data.turn, event.data.step, event.time),
      }
    case 'tool/result': {
      const result = event.data.message.content[0]
@@ -170,6 +174,8 @@ export class TranscriptAdapter {
  /** Transcript nodes in log order; copy-on-write so a published array never mutates. */
  private projected: ConversationNode[] = []
  private callIdx = new Map<string, CallIndexEntry>()
+  /** Per-step timing boundaries (step/start + first token delta), consumed when the step's assistant/message materializes. */
+  private stepTimings = new Map<string, AssistantStepMetadata>()
  /** Wire result views keyed by the tool/result event's seq (views ride the envelope, not the event). */
  private resultViews = new Map<number, ToolResultView>()
  /**
@@ -200,6 +206,7 @@ export class TranscriptAdapter {
    this.callIdx = new Map()
    this.resultViews.clear()
    this.commandIdx = new Map()
+    this.stepTimings = 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. */
@@ -207,6 +214,7 @@ export class TranscriptAdapter {
      this.eventIndex.set(event.seq, event)
      this.indexCall(event, views?.[i])
      this.indexCommand(event)
+      indexAssistantStepTiming(this.stepTimings, event)
    }
    // Indexes first, then project: a tool/result materializes against the
    // complete call index, and a checkpoint against the complete event index.
@@ -229,6 +237,7 @@ export class TranscriptAdapter {
  append(event: SessionEvent, view?: ToolEventView): void {
    this.eventIndex.set(event.seq, event)
    this.indexCall(event, view)
+    indexAssistantStepTiming(this.stepTimings, event)
    if (this.indexCommand(event)) this.rev++
    if (!isTranscriptEvent(event)) return
    this.projected = [...this.projected, this.materialize(event)]
@@ -267,7 +276,7 @@ export class TranscriptAdapter {
  private materialize(event: SessionEvent): ConversationNode {
    return isCompactCheckpoint(event)
      ? materializeCompaction(event, this.eventIndex)
-      : materializeNode(event, this.callIdx, this.resultViews.get(event.seq) ?? null)
+      : materializeNode(event, this.callIdx, this.resultViews.get(event.seq) ?? null, this.stepTimings)
  }

  /**
--- a/Show More
+++ b/Show More