feat(tools): require cancellation signal on every invocation

packages/examples/cli-demo/tests/cli-demo.spec.ts

@@ -10,6 +10,8 @@ import type { ToolExecution } from '@deepseek-ai/dsh-tools'
 import { afterEach, describe, expect, it, vi } from 'vitest'
 import * as cliDemo from '../src/index.ts'
 
+const testToolSignal = new AbortController().signal
+
 const contexts: Context[] = []
 
 async function skillConfig(catalogDescriptionMaxLength?: number): Promise<NonNullable<cliDemo.Config['skills']>> {
@@ -122,6 +124,7 @@ describe('dsh-cli-demo app composition', () => {
 
     expect(ctx.get('agentLoop')?.config.maxParallelToolCalls).toBe(3)
     const execution: ToolExecution = {
+      signal: testToolSignal,
       token: Symbol('cli-demo-dsh-home-test') as ToolExecution['token'],
       callId: CallId('cli-demo-dsh-home'),
       name: 'bash',
@@ -139,11 +142,12 @@ describe('dsh-cli-demo app composition', () => {
     })
     const wait = vi.spyOn(ctx.tasks, 'wait')
     await ctx.tools.execute({
+      signal: testToolSignal,
       callId: CallId('cli-demo-task-config'),
       name: 'task_output',
       arguments: { task_id: id, wait: true },
     })
-    expect(wait).toHaveBeenCalledWith(id, 7, undefined, undefined)
+    expect(wait).toHaveBeenCalledWith(id, 7, undefined, testToolSignal)
   })
 
   it('accepts false to keep task services without model-facing task controls', async () => {