- Add PrometheusMetricsIntegrationTest class with 7 comprehensive tests
- Test Prometheus server startup, custom metrics availability, and port conflict handling
- Test metrics increment, different labels, histogram metrics, and production mode
- Use random ports (9470-9570) to avoid conflicts between tests
- Make tests lenient about custom metrics timing (collection delays)
- Update OpenTelemetry configuration to handle MeterProvider conflicts gracefully
- Update documentation to clarify production vs development Prometheus usage
- Ensure metrics are properly exported via OTLP in production
- Verify comprehensive test coverage for CI environments
All 34 OpenTelemetry tests pass successfully.
