Release v0.0.2

New features:
- Add cache write tokens metric (openclaw_session_tokens_cache_write_total)
- Add cache hit rate calculation (openclaw_session_cache_hit_rate)
- Add session duration tracking (openclaw_session_duration_seconds)
- Add error count tracking (openclaw_session_errors_total)
- Improve collector architecture with better observability
- Add Makefile for common development tasks
- Add golangci-lint configuration for code quality

Release version 0.0.1

Initial release of openclaw_exporter with the following features:
- Session metrics tracking (tokens, cost, messages, model info)
- Workspace metrics (file sizes, health checks, memory files)
- Support for multiple agent monitoring
- Prometheus metrics exporter on port 9101
- Cross-platform builds (Linux, macOS, Windows)

Changes in this release:
- Fixed module name typo (openclaw_expoter -> openclaw_exporter)
- Added MIT LICENSE
- Updated .goreleaser.yml for proper binary naming