Add explicit Gatherer() method to improve API discoverability
and prevent users from accidentally using prometheus.DefaultGatherer
instead of the custom registry.
Changes:
- Add Gatherer() method returning prometheus.Gatherer interface
- Add NewWithDefaultGatherer() constructor for opt-in default usage
- Update package docs with usage examples
- Add tests for both gatherer modes
- Create new metrics/ package for OpenTelemetry-native metrics with OTLP export
- Refactor OTLP configuration to internal/tracerconfig/ to eliminate code duplication
- Add consistent retry configuration across all HTTP OTLP exporters
- Add configuration validation and improved error messages
- Include test coverage for all new functionality
- Make OpenTelemetry metrics dependencies explicit in go.mod
Designed for new applications requiring structured metrics export to
observability backends via OTLP protocol.
