Missing Circuit Breaker Patterns

**Severity:** Low
**Affected Services:** All with service-to-service calls

**Problem:**
No resilience patterns specified for cascading failures.

**Resolution:**
Add circuit breaker configuration to infrastructure spec:

```yaml
circuit_breaker:
  failure_threshold: 5
  success_threshold: 2
  timeout_ms: 30000
  half_open_requests: 3
```