Fix smoke harness timeout so coverage gates are meaningful

[jmcte]

Context

Local verification found the normal Vitest suite is not currently green:

pnpm test
test/smoke-harness.test.ts > runner registration smoke harness > serves deterministic registration and cleanup tokens
Error: Test timed out in 5000ms.

This also blocks pnpm test:coverage, so coverage thresholds are not giving a clean signal until the smoke harness is deterministic again.

Scope

• Fix the timeout in test/smoke-harness.test.ts.
• Keep the smoke harness deterministic and local-only.
• Avoid weakening or deleting the registration/cleanup token assertions.
• Confirm both normal test and coverage runs are green.

Acceptance Criteria

• pnpm test passes locally.
• pnpm test:coverage passes locally.
• The failing smoke harness test continues to assert both registration and cleanup token behavior.
• Any timeout increase is justified by deterministic startup behavior, not used to hide a hanging process.