test(deflake): run.scm-lite.integration — 1/5 flaky (port & startup race)

[Talchain]

Context

After deflake phase 1 (PR #46), this test remains flaky at 1/5 failure rate.

Failing File

• tests/run.scm-lite.integration.test.ts

Root Cause

Port conflicts and startup race conditions causing intermittent failures.

Action Plan

1. Use ephemeral port: server.listen(0) then read server.address().port
2. Await readiness: await once(server, 'listening') before sending requests
3. Serialize the suite: avoid test.concurrent in this file
4. Ensure full teardown:
   • afterAll closes server, destroys clients
   • await new Promise(r => setTimeout(r, 50)) after close to drain timers
5. If worker/child process involved: add unique namespace (env suffix) per test and kill on teardown

Definition of Done

• Test passes 5/5 runs consistently
• Ephemeral port allocation implemented
• Proper readiness awaiting
• Clean teardown with timer drain

Proof Command

for i in {1..5}; do npx vitest run tests/run.scm-lite.integration.test.ts; done

Related

• PR test(deflake): stabilize flaky tests - variance ±4→±1 (-3 worst-case) #46 (deflake phase 1)
• Part of stabilization effort to reach ≤3 failing files