feat: add cross-compile and release pipeline

- Enhanced Makefile with cross-compilation for linux/amd64, linux/arm64,
  darwin/arm64, windows/amd64, windows/arm64
- Added GitHub Actions CI workflow for testing on all platforms
- Added GitHub Actions Release workflow triggered by version tags
- Added VERSION file for version tracking
- Added scripts/release.sh for automated release process
- Added Dockerfile for containerized builds
- Added CONTRIBUTING.md with release process documentation
- Added CHANGELOG.md for version tracking
- Updated .gitignore to exclude build artifacts
- Fixed unused variable in cmd/obm/main.go
- Version now injected via ldflags (main.version, main.gitCommit, main.buildTime)

CHANGELOG.md

@@ -0,0 +1,35 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+## [0.1.0] - 2026-05-22
+
+### Added
+- Initial release of `obm` CLI tool
+- Interactive deployment wizard (`obm deploy`)
+- Configuration validation (`obm validate`)
+- Infrastructure status checking (`obm status`)
+- Deployment teardown (`obm destroy`)
+- Multi-provider support (Hetzner, DigitalOcean)
+- Multi-inference-provider support (ZAI, Venice, OpenRouter)
+- Tailscale VPN integration
+- Discord bot configuration
+- Cross-compilation support for Linux, macOS, Windows
+- GitHub Actions CI/CD pipeline
+- Automated release workflow with binaries
+
+### Infrastructure
+- CI workflow for testing on all platforms
+- Release workflow triggered by version tags
+- Docker container support
+- Makefile with comprehensive build targets
+
+### Documentation
+- README with usage examples
+- CONTRIBUTING guide with release process
+- CHANGELOG for version tracking