feat: add Dockerfile, dry-run mode, and documentation

- Add Dockerfile with multi-stage build using UV
- Add --dry-run CLI flag to log metrics instead of submitting
- Add comprehensive README with usage and metrics documentation
- Fix ruff linter warnings
- Add uv.lock for reproducible builds

.dockerignore

@@ -0,0 +1,40 @@
+# Git
+.git
+.gitignore
+
+# Python
+__pycache__
+*.py[cod]
+*$py.class
+*.egg-info
+.eggs
+dist
+build
+.venv
+venv
+env
+
+# IDE
+.idea
+.vscode
+*.swp
+*.swo
+
+# Config with secrets
+.env
+config.yaml
+config.yml
+
+# Documentation
+*.md
+!README.md
+
+# Tests
+tests
+.pytest_cache
+.coverage
+htmlcov
+
+# Development
+.ruff_cache
+.mypy_cache