refactor: unify agent and session identity

packages/subagent/subagent-spawn/tests/spawn.e2e.ts

@@ -3,8 +3,8 @@ import { tmpdir } from 'node:os'
 import { join } from 'node:path'
 import { afterEach, describe, expect, it } from 'vitest'
 import type { Context } from 'cordis'
-import { AgentId } from '@deepseek-ai/dsh-agent'
 import { spawnHarness, waitForIdle } from './harness.ts'
+import { SessionId } from '@deepseek-ai/dsh-session'
 
 /**
  * With-key smoke for the in-process spawn backend: a REAL parent agent delegates
@@ -29,7 +29,7 @@ describe.skipIf(!process.env.DEEPSEEK_API_KEY)('spawn backend with-key smoke', (
   it('a parent delegates to a child that writes a file on disk', async () => {
     workdir = await mkdtemp(join(tmpdir(), 'dsh-subagent-spawn-e2e-'))
     ctx = await spawnHarness(workdir)
-    const parent = ctx.agentLoop.create(AgentId('e2e-parent'), { model: 'deepseek-v4-flash' })
+    const parent = ctx.agentLoop.create(SessionId('e2e-parent'), { model: 'deepseek-v4-flash' })
 
     parent.send([{ type: 'text', text:
       'Use the subagent tool to delegate this exact task: "Use the bash tool to write the text '