fix(web): deduplicate subagent navigation

packages/core/agent/src/index.ts

@@ -48,9 +48,9 @@ export interface CreateAgentOptions {
   readonly sessionId: SessionId
   /**
    * Session creation metadata: validated absolute `cwd`, `parentSession`
-   * fork lineage, the `seedLength` seed boundary, and the `delegationDepth`
-   * recursion budget. Mirrors the
-   * `cwd`/`parentSession`/`seedLength`/`delegationDepth` fields of
+   * fork lineage, the `seedLength` seed boundary, the coarse `origin`
+   * classification, and the `delegationDepth` recursion budget. Mirrors the
+   * `cwd`/`parentSession`/`seedLength`/`origin`/`delegationDepth` fields of
    * {@link CreateSessionOptions.meta} in dsh-session (the internal-only
    * `createdAt`, used when reconstructing a persisted session, is deliberately
    * excluded — a factory caller never sets it). This is durable session data,
@@ -61,6 +61,7 @@ export interface CreateAgentOptions {
     readonly cwd?: string
     readonly parentSession?: SessionId
     readonly seedLength?: number
+    readonly origin?: 'subagent'
     readonly delegationDepth?: number
   }
   /**

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: 4730cac913e949d642d049a5c53ab2dd47e10627
-README.zh.md: 12aa1625d7b0568196cd788c2a25cfb869d8780d
+README.md: d78dc5bcfe1df2edd01280208f3859eb1b2d6763
+README.zh.md: 40c58a539d5027f2619b5b2102b94e76f2c73e23

packages/core/session/README.md

@@ -12,7 +12,7 @@ Creates and holds event-sourced `Session` instances. Persistence is intentionall
 
 ### Public API
 
-- `ctx.sessions.create(id?, { seed?, meta? }?)` validates and detaches durable seed/header data, fills the version and id, defaults `createdAt` to now, publishes the session, and binds it to the calling fiber. Persisted reconstruction supplies its original `createdAt`, `seedLength`, and `delegationDepth`.
+- `ctx.sessions.create(id?, { seed?, meta? }?)` validates and detaches durable seed/header data, fills the version and id, defaults `createdAt` to now, publishes the session, and binds it to the calling fiber. Persisted reconstruction supplies its original `createdAt`, `seedLength`, `origin`, and `delegationDepth`.
 - `ctx.sessions.flush(session)` dispatches the awaited parallel durability checkpoint through the session's captured scope. Every listener starts and the call waits for all to settle before reporting failure; it returns `true` when at least one listener participated and `false` for an empty snapshot, while unpublished, detached, and stale objects reject. A caller that requires durable storage rejects `false` at its own policy boundary.
 - `findLastMessageTurnEnd(events)` pairs message-triggered starts with their ends and returns the latest matched `turn/end`. Outcome consumers use this fold instead of the raw latest log event because between-turn records and non-message turns have no prompt outcome.
 - `ctx.sessions.fork(source, boundary?, childSessionId?): Session` — Resolve a live session object or id, select a seed through the inclusive `boundary` event seq (default: current last event), require that prefix to end outside an open turn, and create a live child session with lineage metadata.
@@ -43,7 +43,7 @@ Plain class (not a Cordis Service). Create via `ctx.sessions.create()`.
 - `session.surface` exposes the readonly `SessionSurface` view owned by the session's single incremental surface manager; `replaceGeneration` changes on every committed rewrite.
 - `session.events` is a cached frozen snapshot invalidated by append; accepted events remain deeply frozen.
 - `session.seq`, `session.id` — current sequence and readonly typed identity.
-- `session.header: SessionHeader` — detached, deep-frozen creation metadata (`version`, `id`, `createdAt`, optional `cwd`/`parentSession`/`seedLength`/`delegationDepth`). Construction validates the durable record and requires its id to match `session.id`.
+- `session.header: SessionHeader` — detached, deep-frozen creation metadata (`version`, `id`, `createdAt`, optional `cwd`/`parentSession`/`seedLength`/`origin`/`delegationDepth`). `origin: 'subagent'` is a coarse product classification, not a continuation capability. Construction validates the durable record and requires its id to match `session.id`.
 
 ### Lossless JSON utilities
 
@@ -89,7 +89,7 @@ Every `SessionEvent` carries two optional top-level fields (structural metadata)
 
 ### Metadata types (`types.ts`)
 
-- `SessionHeader` — session metadata written once when published as `Session.header`, where detachment and deep-freezing enforce immutability at runtime: `{ version, id, createdAt, cwd?, parentSession?, seedLength?, delegationDepth? }`. Persistence loaders may return mutable detached copies of the same data type. Owned here (beside `SessionId`) because `Session.header` is typed by it; persistence backends re-export it rather than own it (which would force a package cycle).
+- `SessionHeader` — session metadata written once when published as `Session.header`, where detachment and deep-freezing enforce immutability at runtime: `{ version, id, createdAt, cwd?, parentSession?, seedLength?, origin?, delegationDepth? }`. Persistence loaders may return mutable detached copies of the same data type. Owned here (beside `SessionId`) because `Session.header` is typed by it; persistence backends re-export it rather than own it (which would force a package cycle).
 
 ### Extension points
 

packages/core/session/README.zh.md

@@ -12,7 +12,7 @@
 
 ### 公共 API
 
-- `ctx.sessions.create(id?, { seed?, meta? }?)` 校验持久种子／头部数据并生成脱离副本，补齐版本和 id，在未提供 `createdAt` 时使用当前时间，发布会话并将其绑定到调用方 fiber。持久化重建会提供原始的 `createdAt`、`seedLength` 和 `delegationDepth`。
+- `ctx.sessions.create(id?, { seed?, meta? }?)` 校验持久种子／头部数据并生成脱离副本，补齐版本和 id，在未提供 `createdAt` 时使用当前时间，发布会话并将其绑定到调用方 fiber。持久化重建会提供原始的 `createdAt`、`seedLength`、`origin` 和 `delegationDepth`。
 - `ctx.sessions.flush(session)` 通过会话捕获的作用域分发受等待的并行持久性检查点。每个监听器都会启动；调用会等待全部结算后才报告失败；至少一个监听器参与时返回 `true`，监听器快照为空时返回 `false`，而未发布、已脱离和陈旧的对象会被拒绝。要求持久化存储的调用方应在自己的策略边界拒绝 `false`。
 - `findLastMessageTurnEnd(events)` 将由消息触发的开始与结束配对，并返回最近匹配的 `turn/end`。结果消费方使用该折叠逻辑，而不直接取日志中最近的事件，因为轮次间记录和非消息轮次没有提示词结果。
 - `ctx.sessions.fork(source, boundary?, childSessionId?): Session`：解析实时会话对象或 id，选取截至 `boundary` 事件序号（含该事件）的种子（默认为当前最后一个事件），要求所选前缀结束时没有开放轮次，再创建带谱系元数据的实时子会话。
@@ -43,7 +43,7 @@
 - `session.surface` 暴露只读 `SessionSurface` 视图，由会话唯一的增量 surface 管理器所有；每次提交重写，`replaceGeneration` 都会变化。
 - `session.events` 是按追加失效的缓存冻结快照；已接受事件保持深度冻结。
 - `session.seq`、`session.id`：当前序号和只读类型化身份。
-- `session.header: SessionHeader`：脱离、深冻结的创建元数据（`version`、`id`、`createdAt`，以及可选的 `cwd`／`parentSession`／`seedLength`／`delegationDepth`）。构造时会校验持久记录，并要求其中的 id 与 `session.id` 一致。
+- `session.header: SessionHeader`：脱离、深冻结的创建元数据（`version`、`id`、`createdAt`，以及可选的 `cwd`／`parentSession`／`seedLength`／`origin`／`delegationDepth`）。`origin: 'subagent'` 是粗粒度产品分类，不代表具备继续执行能力。构造时会校验持久记录，并要求其中的 id 与 `session.id` 一致。
 
 ### 无损 JSON 工具
 
@@ -89,7 +89,7 @@
 
 ### 元数据类型（`types.ts`）
 
-- `SessionHeader`：会话元数据，在发布为 `Session.header` 时写入一次；脱离和深冻结保证运行时不可变：`{ version, id, createdAt, cwd?, parentSession?, seedLength?, delegationDepth? }`。持久化 loader 可返回相同数据类型的可变脱离副本。该类型由此包与 `SessionId` 一同所有，因为 `Session.header` 以它为类型；持久化后端只是重新导出而不拥有它，否则会形成包循环依赖。
+- `SessionHeader`：会话元数据，在发布为 `Session.header` 时写入一次；脱离和深冻结保证运行时不可变：`{ version, id, createdAt, cwd?, parentSession?, seedLength?, origin?, delegationDepth? }`。持久化 loader 可返回相同数据类型的可变脱离副本。该类型由此包与 `SessionId` 一同所有，因为 `Session.header` 以它为类型；持久化后端只是重新导出而不拥有它，否则会形成包循环依赖。
 
 ### 扩展点
 

packages/core/session/src/index.ts

@@ -138,6 +138,9 @@ function snapshotSessionHeader(id: SessionId, source?: SessionHeader): SessionHe
     && (typeof record.seedLength !== 'number' || !Number.isSafeInteger(record.seedLength) || record.seedLength < 0)) {
     throw new Error('session header seedLength must be a non-negative safe integer')
   }
+  if (record.origin !== undefined && record.origin !== 'subagent') {
+    throw new Error('session header origin must be "subagent"')
+  }
   if (record.delegationDepth !== undefined
     && (typeof record.delegationDepth !== 'number' || !Number.isSafeInteger(record.delegationDepth) || record.delegationDepth < 0)) {
     throw new Error('session header delegationDepth must be a non-negative safe integer')
@@ -837,6 +840,7 @@ export class SessionStore extends Service {
       ...meta?.cwd === undefined ? {} : { cwd: meta.cwd },
       ...meta?.parentSession === undefined ? {} : { parentSession: meta.parentSession },
       ...meta?.seedLength === undefined ? {} : { seedLength: meta.seedLength },
+      ...meta?.origin === undefined ? {} : { origin: meta.origin },
       ...meta?.delegationDepth === undefined ? {} : { delegationDepth: meta.delegationDepth },
     }
     return new Session(sessionId, seed, header)

packages/core/session/src/types.ts

@@ -59,6 +59,11 @@ export interface SessionHeader {
    * boundary lets resume and replay distinguish parent history from child work.
    */
   readonly seedLength?: number
+  /**
+   * Coarse product classification for a session created as a subagent child.
+   * This is presentation metadata, not proof that the child is continuable.
+   */
+  readonly origin?: 'subagent'
   /**
    * Delegation depth: absent (zero) for a top-level session, parent depth + 1
    * for a subagent child. Persisted so a recursion budget survives restart and
@@ -84,6 +89,7 @@ export interface CreateSessionOptions {
     readonly parentSession?: SessionId
     readonly createdAt?: number
     readonly seedLength?: number
+    readonly origin?: 'subagent'
     readonly delegationDepth?: number
   }
 }

packages/core/session/tests/session.spec.ts

@@ -1251,15 +1251,16 @@ describe('SessionStore', () => {
     })
   })
 
-  it('attaches delegationDepth from meta to the header', async () => {
+  it('attaches subagent origin and delegationDepth from meta to the header', async () => {
     const ctx = new Context()
     await ctx.plugin(SessionStore)
     const session = ctx.sessions.create(SessionId('delegated-child'), {
-      meta: { parentSession: SessionId('parent'), delegationDepth: 2 },
+      meta: { parentSession: SessionId('parent'), origin: 'subagent', delegationDepth: 2 },
     })
     expect(session.header).toMatchObject({
       id: 'delegated-child',
       parentSession: 'parent',
+      origin: 'subagent',
       delegationDepth: 2,
     })
   })
@@ -1278,6 +1279,7 @@ describe('SessionStore', () => {
       { meta: { seedLength: '1' }, error: /seedLength must be a non-negative safe integer/ },
       { meta: { seedLength: 0.5 }, error: /seedLength must be a non-negative safe integer/ },
       { meta: { seedLength: -1 }, error: /seedLength must be a non-negative safe integer/ },
+      { meta: { origin: 'fork' }, error: /origin must be "subagent"/ },
       { meta: { delegationDepth: '1' }, error: /delegationDepth must be a non-negative safe integer/ },
       { meta: { delegationDepth: 0.5 }, error: /delegationDepth must be a non-negative safe integer/ },
       { meta: { delegationDepth: -1 }, error: /delegationDepth must be a non-negative safe integer/ },