feat: optimize subagent list children query

packages/client/runtime/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/client/runtime/README.md
-README.md: 0f5b35b6fa4a92f083d5e20c354c19eaae1d5b70
-README.zh.md: 67cdf6479ef2ba7156b7babb7249b51f8640b134
+README.md: e4b8e1777ad3a01144dfe9da0a81f83e0f4e2b6a
+README.zh.md: 5aa53ce1ec680579b44f0b2859104a1eda7471d3

packages/client/runtime/README.md

@@ -56,7 +56,7 @@ Each resident `Session` owns a `modelSelection` snapshot containing the current
 
 ## Addressed subagent conversations
 
-`SessionListState.subagentsByParent` carries direct durable catalogs and `currentAddress` records the catalog-derived `{parentSessionId, childSessionId}` for the selected child. Only that recorded address selects subagent transport: lineage alone remains insufficient because ordinary forks also have `parentId`. An addressed Session loads and reconnects through `subagent.history`, sends through `subagent.prompt`, never calls ordinary cancel, and persists its address with the selected session across refresh and repeated ordinary selection of that same child. The list also projects the header's coarse `origin: 'subagent'` classification for navigation filtering; the recorded address, not `origin`, remains transport authority. Catalog reads are single-flight; `host/session-status` flips a listed child's coarse activity in place, while `host/session-added` causes one debounced refetch only while that parent catalog is open. Parent availability propagates into `ConversationSnapshot.subagent` so presentation can replace the composer with a read-only explanation without activating the parent.
+`SessionListState.subagentsByParent` carries direct durable catalogs and `currentAddress` records the catalog-derived `{parentSessionId, childSessionId}` for the selected child. Only that recorded address selects subagent transport: lineage alone remains insufficient because ordinary forks also have `parentId`. An addressed Session loads and reconnects through `subagent.history`, sends through `subagent.prompt`, never calls ordinary cancel, and persists its address with the selected session across refresh and repeated ordinary selection of that same child. The list also projects the header's coarse `origin: 'subagent'` classification for navigation filtering; the recorded address, not `origin`, remains transport authority. Catalog reads are single-flight; `host/session-status` flips a listed child's coarse activity in place, while an origin-classified `host/session-added` immediately marks any loaded direct parent row `hasChildren: true` and causes one debounced refetch when that parent is selected or its catalog is open. Parent availability propagates into `ConversationSnapshot.subagent` so presentation can replace the composer with a read-only explanation without activating the parent.
 
 ## Model Experience
 

packages/client/runtime/README.zh.md

@@ -56,7 +56,7 @@ Session 对象会在事件 wire 边界依据生产方的完整字段契约，验
 
 ## 已寻址的 subagent 对话
 
-`SessionListState.subagentsByParent` 携带直接持久化目录，`currentAddress` 则记录所选 child 从目录得到的 `{parentSessionId, childSessionId}`。只有这份已记录地址能选择 subagent 传输；单凭谱系仍然不足，因为普通 fork 同样具有 `parentId`。已寻址的 Session 通过 `subagent.history` 加载和重连，通过 `subagent.prompt` 发送，绝不调用普通取消，并在刷新期间及通过普通选择路径重复选择同一 child 时，把地址与所选会话一同持久化。列表还会投影 header 的粗粒度 `origin: 'subagent'` 分类供导航过滤；传输的权威依据仍是已记录地址，而不是 `origin`。目录读取为 single-flight；`host/session-status` 就地翻转已列 child 的粗粒度活动状态，`host/session-added` 则只在对应 parent 目录打开时触发一次去抖动的重拉。parent 可用性会传播到 `ConversationSnapshot.subagent`，使呈现层可以把编辑器替换为只读说明，而不激活 parent。
+`SessionListState.subagentsByParent` 携带直接持久化目录，`currentAddress` 则记录所选 child 从目录得到的 `{parentSessionId, childSessionId}`。只有这份已记录地址能选择 subagent 传输；单凭谱系仍然不足，因为普通 fork 同样具有 `parentId`。已寻址的 Session 通过 `subagent.history` 加载和重连，通过 `subagent.prompt` 发送，绝不调用普通取消，并在刷新期间及通过普通选择路径重复选择同一 child 时，把地址与所选会话一同持久化。列表还会投影 header 的粗粒度 `origin: 'subagent'` 分类供导航过滤；传输的权威依据仍是已记录地址，而不是 `origin`。目录读取为 single-flight；`host/session-status` 就地翻转已列 child 的粗粒度活动状态，按 origin 分类的 `host/session-added` 则会立即把任何已加载的直接 parent 行标记为 `hasChildren: true`，并在该 parent 被选中或其目录打开时触发一次去抖动的重拉。parent 可用性会传播到 `ConversationSnapshot.subagent`，使呈现层可以把编辑器替换为只读说明，而不激活 parent。
 
 ## 模型体验
 

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

@@ -616,6 +616,9 @@ export class SessionManager {
           ...(frame.cwd !== undefined ? { cwd: frame.cwd } : {}),
         })
         this.sessions.get(frame.sessionId)?.handleBlank(frame.blank)
+        if (frame.origin === 'subagent' && frame.parentSessionId !== undefined) {
+          this.markCatalogParentExpandable(frame.parentSessionId)
+        }
         if (frame.parentSessionId !== undefined
           && (this.selected === frame.parentSessionId || this.openCatalogs.has(frame.parentSessionId))) {
           this.scheduleCatalogRefresh(frame.parentSessionId)
@@ -714,6 +717,22 @@ export class SessionManager {
     if (changed) this.notifier.markDirty()
   }
 
+  /** Mark a loaded parent row expandable after one direct subagent publishes. */
+  private markCatalogParentExpandable(parentSessionId: SessionId): void {
+    let changed = false
+    for (const [catalogParentId, catalog] of this.catalogs) {
+      if (!catalog.entries.some(entry =>
+        entry.kind === 'child' && entry.id === parentSessionId && !entry.hasChildren)) continue
+      const entries = catalog.entries.map((entry) => {
+        if (entry.kind !== 'child' || entry.id !== parentSessionId || entry.hasChildren) return entry
+        return { ...entry, hasChildren: true }
+      })
+      changed = true
+      this.catalogs.set(catalogParentId, { ...catalog, entries })
+    }
+    if (changed) this.notifier.markDirty()
+  }
+
   private buildListSnapshot(): SessionListSnapshot {
     const merged: TitledSessionSummary[] = this.summaries.map((summary) => {
       // List rows read the generic 'title' projection key (host-computed unit

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

@@ -287,7 +287,8 @@ describe('subagent catalogs', () => {
     ] as never[] }))
     api.onSubagentList = () => Promise.resolve(ok({
       entries: [{
-        kind: 'child', id: S2, mode: 'continuable', label: 'worker', activity: 'running',
+        kind: 'child', id: S2, mode: 'continuable', label: 'worker',
+        activity: 'running', hasChildren: false,
       }] as never[],
       parentAvailable: true,
     }))
@@ -385,6 +386,46 @@ describe('subagent catalogs', () => {
       vi.useRealTimers()
     }
   })
+
+  it('marks a loaded parent row expandable only for a direct subagent publication', async () => {
+    const api = new FakeApiClient()
+    const root = 'fk-root' as SessionId
+    api.onSubagentList = () => Promise.resolve(ok({
+      entries: [
+        {
+          kind: 'child', id: S1, mode: 'continuable', label: 'parent',
+          activity: 'inactive', hasChildren: false,
+        },
+        {
+          kind: 'child', id: S2, mode: 'continuable', label: 'ordinary parent',
+          activity: 'inactive', hasChildren: false,
+        },
+      ] as never[],
+      parentAvailable: true,
+    }))
+    const manager = new SessionManager(api)
+    await manager.refreshSubagents(root)
+
+    manager.handleHostEnvelope({
+      rpcId: 'nested-subagent' as never,
+      payload: {
+        type: 'host/session-added', sessionId: 'fk-grandchild' as SessionId,
+        parentSessionId: S1, origin: 'subagent', blank: false,
+      },
+    })
+    manager.handleHostEnvelope({
+      rpcId: 'ordinary-fork' as never,
+      payload: {
+        type: 'host/session-added', sessionId: 'fk-fork' as SessionId,
+        parentSessionId: S2, blank: false,
+      },
+    })
+
+    expect(manager.getListSnapshot().subagentsByParent[root]?.entries).toMatchObject([
+      { kind: 'child', id: S1, hasChildren: true },
+      { kind: 'child', id: S2, hasChildren: false },
+    ])
+  })
 })
 
 describe('remaining branches', () => {