- Remove all 25ms and 50ms sleeps from agent_channel_test
- Add poll_until helper for async DB operations (early exit on success)
- Reduce timeout test sleeps from 100ms to 60ms
- Reduce polling delays from 10ms to 5ms in multiple tests
- Remove unnecessary timestamp and background task sleeps
- Reduce circuit breaker recovery sleep from 150ms to 110ms
Performance: 30.3s → 28.3s (6.6% faster)
Total improvement from baseline: 52s → 28.3s (45.6% faster)