v0.1.20

Changed

• README restructured as landing page: demo GIF moved to top, feature cards, installation earlier, CLI reference and Python API moved to docs/ subpages.
• Banner updated to docs/banner.png.
• Mermaid flowchart: removed <br/> tags for GitHub compatibility, added plain-text fallback.
• Added system prompt template and token efficiency table for AI agent integrators.
• TEST.md now installs with [dev,llm] extras (ruff available for lint step).

---