test(acp): await cancelled tool updates

packages/support/acp-snapshot/tests/harness.spec.ts

@@ -334,14 +334,26 @@ describe('runScenario', () => {
     expect(result.rawStdout.indexOf('thinking about it')).toBeLessThan(result.rawStdout.indexOf('cancelled'))
   })
 
-  it('promptAndCancel can wait for a tool call before cancelling', { timeout: 20_000 }, async () => {
-    const { fixtureFile } = await scenario({ prompt: 'hang-until-cancel', cancelAtToolCall: true })
+  it('promptAndCancel can bracket cancellation with tool-call updates', { timeout: 20_000 }, async () => {
+    const { fixtureFile } = await scenario({
+      prompt: 'hang-until-cancel',
+      cancelAtToolCall: true,
+      cancelToolCallUpdate: true,
+    })
     const result = await runScenario(
-      { steps: [...boot, { op: 'promptAndCancel', text: 'hang', afterUpdate: 'tool_call' }] },
+      {
+        steps: [...boot, {
+          op: 'promptAndCancel',
+          text: 'hang',
+          afterUpdate: 'tool_call',
+          waitForToolCallUpdate: 'call_fake_1',
+        }],
+      },
       { agent: AGENT, mode: 'replay', fixtureFile },
     )
     expect(result.rawStdout).toContain('"sessionUpdate":"tool_call"')
     expect(result.rawStdout.indexOf('"sessionUpdate":"tool_call"')).toBeLessThan(result.rawStdout.indexOf('cancelled'))
+    expect(result.rawStdout.indexOf('cancelled')).toBeLessThan(result.rawStdout.indexOf('"sessionUpdate":"tool_call_update"'))
   })
 
   it('promptExpectError swallows a model-error response as the expected outcome', { timeout: 20_000 }, async () => {