feat(client): surface subagent activity in sidebar

packages/client/runtime/tests/subagent-lineage.spec.ts

@@ -0,0 +1,53 @@
+import { describe, expect, it } from 'vitest'
+import type { SessionId, SessionSummary } from '@deepseek-ai/dsh-client-runtime/client'
+import { indexSubagentDescendants } from '@deepseek-ai/dsh-client-runtime/client'
+
+const sid = (id: string) => id as SessionId
+
+function summary(
+  id: string,
+  parentId?: SessionId,
+  origin?: 'subagent',
+  running = false,
+): SessionSummary {
+  return {
+    id: sid(id), displayTitle: id, running, blank: false, updatedAt: 0,
+    ...(parentId === undefined ? {} : { parentId }),
+    ...(origin === undefined ? {} : { origin }),
+  }
+}
+
+function index(...summaries: SessionSummary[]) {
+  return indexSubagentDescendants(Object.fromEntries(
+    summaries.map(item => [item.id, item]),
+  ))
+}
+
+describe('indexSubagentDescendants', () => {
+  it('counts every nested descendant and its exact running state', () => {
+    const owner = summary('owner')
+    const child = summary('child', owner.id, 'subagent')
+    const grandchild = summary('grandchild', child.id, 'subagent', true)
+
+    const result = index(owner, child, grandchild)
+    expect(result.get(owner.id)).toEqual({ count: 2, runningCount: 1 })
+    expect(result.get(child.id)).toEqual({ count: 1, runningCount: 1 })
+  })
+
+  it('stops at ordinary forks and fails soft on cycles and missing parents', () => {
+    const owner = summary('owner')
+    const child = summary('child', owner.id, 'subagent', true)
+    const fork = summary('fork', child.id)
+    const forkChild = summary('fork-child', fork.id, 'subagent', true)
+    const orphan = summary('orphan', sid('missing'), 'subagent', true)
+    const cycleA = summary('cycle-a', sid('cycle-b'), 'subagent')
+    const cycleB = summary('cycle-b', sid('cycle-a'), 'subagent')
+
+    const result = index(owner, child, fork, forkChild, orphan, cycleA, cycleB)
+    expect(result.get(owner.id)).toEqual({ count: 1, runningCount: 1 })
+    expect(result.get(fork.id)).toEqual({ count: 1, runningCount: 1 })
+    expect(result.get(sid('missing'))).toEqual({ count: 1, runningCount: 1 })
+    expect(result.get(cycleA.id)).toEqual({ count: 2, runningCount: 0 })
+    expect(result.get(cycleB.id)).toEqual({ count: 2, runningCount: 0 })
+  })
+})