Merge branch 'codex/simp-snapshot-fixture-inventory' into codex/simp-shared-acp-test-launcher

# Conflicts:
#	examples/acp-agent/tests/escalation.e2e.ts
#	packages/support/README.md
#	packages/support/acp-snapshot/README.md
#	packages/support/acp-snapshot/src/harness.ts
#	packages/support/acp-snapshot/tests/harness.spec.ts

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

@@ -234,6 +234,14 @@ describe('runScenario', () => {
     expect(permissionFinished).toBe(true)
   })
 
+  it('includes agent stderr when the ACP connection closes during startup', { timeout: 20_000 }, async () => {
+    const { fixtureFile } = await scenario({ failOnBoot: true, stderrNote: 'fake agent requested startup failure' })
+    await expect(runScenario(
+      { steps: [{ op: 'initialize' }] },
+      { agent: AGENT, mode: 'replay', fixtureFile },
+    )).rejects.toThrow(/agent stderr:\nfake agent requested startup failure/)
+  })
+
   it('drives a full turn: initialize (terminal caps), session, prompt, permission stub, harvest', { timeout: 20_000 }, async () => {
     const { fixtureFile } = await scenario({
       permissionProbe: true,