v0.1.19

✨ Features

• Add breakpoint toggle, step controls, checkpoint diff, and frontier scope controls
• Implement AgentStepper (#183), Swimlane debugger (#193), and Meerkat violation detection (#194)
• Implement research features — reasoning editor (#192) and divergence detection (#184)
• Implement 5 research-inspired features from academic papers
• Add PyPI download stats page with live charts

🐛 Bug Fixes

• Resolve Query object TypeError in violation routes
• Add Python 3.10 StrEnum compatibility shim to causal_tracer and error_attribution
• Make scipy optional in conformal_scorer for CI compatibility
• Fix import sorting for ruff 0.15 compatibility
• Derive comparison loading state to eliminate synchronous setState in effect
• Include [dev] extras in install-dev for new contributors
• Address review feedback — tighten Node engine range and pin nvmrc
• Add Node.js setup step to CI test job for frontend builds
• Fix readme to point to existing README.md
• Use full URL for logo/title nav link
• Correct stepper test fixture and assertions
• Resolve all ruff lint errors across SDK and test files

📦 Other

• Reorganize repo docs and images into structured subdirectories
• Reduce root directory clutter
• Remove broken frontend tests
• Bump frontend and docs dependencies (eslint, vite, typescript, react, zustand)
• Bump GitHub Actions dependencies