docs(session): document creation ownership boundaries

packages/cordis/tool-cordis/src/api-catalog.ts

@@ -2399,7 +2399,7 @@ export const TYPE_API: readonly TypeApiEntry[] = [
   },
   {
     name: 'Session',
-    declaration: 'export class Session {\n    get surface(): SessionSurface;\n    readonly header: SessionHeader;\n    get id(): SessionId;\n    readonly firstLiveSeq: number;\n    constructor(id: SessionId, seed?: readonly SessionEvent[], header?: SessionHeader);\n    get events(): readonly SessionEvent[];\n    get seq(): number;\n    append<T extends SessionEventType>(type: T, data: SessionEventMap[T], ...opts: T extends SurfaceEventType ? [\n        opts: SurfaceIntent\n    ] : [\n    ]): SessionEvent<T>;\n    requestHeader(): EpochHeader | undefined;\n    requestContext(): RequestContext | undefined;\n    deriveMessages(): Message[];\n    deriveEventMessage(event: SessionEvent): Message | null;\n}',
+    declaration: 'export class Session {\n    get surface(): SessionSurface;\n    readonly header: SessionHeader;\n    get id(): SessionId;\n    readonly firstLiveSeq: number;\n    static create(id: SessionId, seed?: readonly SessionEvent[], header?: SessionHeader): Session;\n    get events(): readonly SessionEvent[];\n    get seq(): number;\n    append<T extends SessionEventType>(type: T, data: SessionEventMap[T], ...opts: T extends SurfaceEventType ? [\n        opts: SurfaceIntent\n    ] : [\n    ]): SessionEvent<T>;\n    requestHeader(): EpochHeader | undefined;\n    requestContext(): RequestContext | undefined;\n    deriveMessages(): Message[];\n    deriveEventMessage(event: SessionEvent): Message | null;\n}',
   },
   {
     name: 'SessionAvailability',

packages/core/session/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/core/session/README.md
-README.md: d78dc5bcfe1df2edd01280208f3859eb1b2d6763
-README.zh.md: 9ed9cab5c1c0a3eae6ac8b7bea6bb82b8c668e22
+README.md: ae4f0ccaa3ac3b3742a0856de4445cbd8412ea24
+README.zh.md: ae4adb6afa48e67a3274231d6c9bf303a0086470

packages/core/session/README.md

@@ -35,7 +35,7 @@ The store pairs announced creation with disposal, publishes post-commit append n
 
 ### Class: `Session`
 
-Plain class (not a Cordis Service). Create via `ctx.sessions.create()`.
+Plain class (not a Cordis Service). Create live sessions through `ctx.sessions.create()` and detached replay or inspection sessions through `Session.create()`; the detached factory does not publish lifecycle events or bind the session to a fiber.
 
 - `session.append(type, data, opts?)` snapshots and freezes durable data and surface metadata, validates marker shape, provenance, complete replacement coverage, and content-only single-result `tool/result` rewrites, commits synchronously, then notifies observers with independent failure containment. Reentrant attached-session appends reject, and runtime checks cover widened unions and loaded logs.
 - `session.deriveMessages()` incrementally projects each new surface entry once and returns a fresh array over the complete identified, frozen messages stored by those entries. Assistant messages preserve provider/model provenance and adapter-private replay state in their model source. A surface rewrite rebuilds the projection; there is no raw-log fallback.
@@ -49,6 +49,8 @@ Plain class (not a Cordis Service). Create via `ctx.sessions.create()`.
 
 Durable values need one accepted representation, not a check followed by a second read. `isJsonValue(value)` is the boolean predicate; `snapshotJsonValue(value)` iteratively validates and copies a plain value in one pass, returning `undefined` for invalid input and propagating a throwing getter. The snapshot helper accepts finite JSON numbers except `-0` (JSON rewrites it to `0`), dense ordinary arrays, and plain or null-prototype objects; it rejects cycles, unsupported scalars, and exotic prototypes before normalization without imposing a call-stack depth limit.
 
+Session-event import separates ownership from message validation. `snapshotSessionEvent(event)` clones a borrowed event before validating and freezing its identified message. `adoptSessionEvent(event)` performs the same message work in place and returns the original event; callers may use it only when they transfer an exclusively owned object graph with no mutable child shared with another event.
+
 ### Chunk-row storage codec (`chunk-rows.ts`)
 
 Providers stream token-sized deltas, so a raw log stores hundreds of `assistant/chunk` lines whose JSON envelopes dwarf their payloads. `packChunkRuns(events)` packs each run of ≥3 consecutive same-block delta chunks into one storage row — `text-chunks`, `reasoning-chunks`, or `tool-call-chunks` (bare slash-less tags: storage vocabulary, not `SessionEventMap` members) — and `decodeStorageRecord(value)` expands a parsed line back into its exact events (`seq0`/`time0` + per-member `dt` gaps reconstruct every `seq`/`time`). The encoder whitelists exact shapes and stores anything unrecognized verbatim; the decoder validates row-tagged values and throws on malformation. Owned here so the JSONL backend and the fixture readers (`dsh-llm-replay`, `dsh-acp-snapshot`) share one codec; the backend's default-enabled `packChunks` config controls writes only.

packages/core/session/README.zh.md

@@ -35,7 +35,7 @@
 
 ### 类：`Session`
 
-普通类（不是 Cordis 服务）。通过 `ctx.sessions.create()` 创建。
+普通类（不是 Cordis 服务）。活跃会话通过 `ctx.sessions.create()` 创建，脱离态的回放或检查会话通过 `Session.create()` 创建；脱离态工厂不会发布生命周期事件，也不会将会话绑定到 fiber。
 
 - `session.append(type, data, opts?)` 会为持久数据和 surface 元数据制作快照并冻结它们，校验标记形态、溯源信息、替换覆盖完整性，以及仅修改内容的单个 `tool/result` 重写，随后同步提交，再在彼此独立的失败收容下通知观察者。对已附加会话的重入追加会被拒绝，运行时检查也覆盖扩宽后的联合类型和已加载日志。
 - `session.deriveMessages()` 对每个新的 surface 条目只做一次增量投影，并返回一个新数组，其中包含这些条目存储的完整、带标识且冻结的消息。assistant 消息会在其模型来源中保留提供方／模型溯源信息及适配器私有回放状态。surface 重写会重建投影；不存在原始日志回退。
@@ -49,6 +49,8 @@
 
 持久值需要一种已接受的表示，不能先检查再二次读取。`isJsonValue(value)` 是布尔判断函数；`snapshotJsonValue(value)` 在一趟迭代中校验并复制普通值，无效输入返回 `undefined`，getter 抛出的异常则向外传播。快照辅助函数接受除 `-0` 外的有限 JSON 数值（JSON 会将其改写为 `0`）、稠密普通数组、普通对象或 null 原型对象；它会在规范化前拒绝循环引用、不支持的标量和特殊原型，同时不施加调用栈深度限制。
 
+会话事件导入将所有权与消息校验分开处理。`snapshotSessionEvent(event)` 会先克隆借用的事件，再校验并冻结其中带标识的消息。`adoptSessionEvent(event)` 原地执行相同的消息处理并返回原事件；调用方只有在移交独占的对象图，且该对象图没有与其他事件共享可变子对象时，才可以使用此函数。
+
 ### 分片行存储编解码器（`chunk-rows.ts`）
 
 提供方以 token 大小的增量流式输出，因此原始日志会存储数百行 `assistant/chunk`，其 JSON 封装远大于载荷。`packChunkRuns(events)` 将每段至少 3 个连续、同块的增量分片打包为一个存储行：`text-chunks`、`reasoning-chunks` 或 `tool-call-chunks`（不含斜杠的裸标签，属于存储词汇而不是 `SessionEventMap` 成员）。`decodeStorageRecord(value)` 则将已解析行展开回完全一致的事件（`seq0`／`time0` 加上每个成员的 `dt` 间隔，可重建每个 `seq`／`time`）。编码器只允许精确形态，并逐字存储任何无法识别的内容；解码器校验带行标签的值，形态错误时抛出异常。编解码器由此包所有，使 JSONL 后端和 fixture（测试前置数据）读取器（`dsh-llm-replay`、`dsh-acp-snapshot`）共享同一编解码器；后端默认启用的 `packChunks` 配置只控制写入。

packages/core/session/src/index.ts

@@ -455,8 +455,8 @@ export class Session {
   readonly firstLiveSeq: number
 
   /**
-   * Create a detached session with the same validation and snapshot semantics
-   * formerly provided by direct construction.
+   * Create a detached session by validating and snapshotting borrowed seed
+   * events and storage metadata.
    * @param id - session identity.
    * @param seed - optional borrowed replay or fork events.
    * @param header - optional borrowed storage metadata.