v0.18.1

Documentation

• Regenerated docs/language-reference.md to spec parity. Added five
  missing sections: §13A PERT, §18 Mindmap, §21 Cycle, §22 Journey
  Map, and §26 Authoring Rules. Renumbered Tech Radar, Pyramid, Ring,
  RACI, and Colon Usage Summary to match spec ordering; swapped
  Wireframe + Tech Radar to align with spec source order. The MCP
  get_language_reference tool now serves complete documentation for
  every chart type.
• Migrated residual pipe-metadata examples in README.md to §1.4
  same-line form. The org-chart sample and the "single-line with pipe
  delimiter" prose subsection had been left out of the 0.18.0 pipe
  retirement sweep.