Add core API documentation and update navigation structure

[bhairaav]

Summary

This PR adds comprehensive documentation for the core OpenGeometry API and reorganizes the documentation navigation to better reflect the library's architecture and user workflows.

Key Changes

New Documentation Pages

• api/core/opengeometry.mdx — Documents the OpenGeometry singleton class, including initialization via create(), the enableDebug property for debug rendering, version information, and code examples for basic setup and debug mode usage
• api/core/vector3.mdx — Documents the Vector3 wasm-backed 3D coordinate type, including constructor parameters and usage examples with primitives and shapes
• api/scene/spot-label.mdx — Documents the SpotLabel CSS2D markup component for annotating points on geometry in Three.js scenes

Navigation & Configuration Updates

• Reorganized .atlas-analysis.json navigation structure:

  • Renamed "Get Started" group to "Introduction" with updated page references
  • Consolidated "Core Concepts" group by removing "Integration" section
  • Added new "Core" group under API Documentation containing opengeometry and vector3
  • Reorganized "Scene & Export" into separate "Export (Experimental)" and "Scene" groups
  • Added api/shapes/opening and api/operations/boolean-operations to shape/operation lists
  • Updated publicApiSurface to reflect current exports (OpenGeometry, Vector3, OGSceneManager, SpotLabel, export types)
  • Added metadata fields: extractedAt, sourceRef, entryFile

• Updated theme colors in .atlas-analysis.json:

  • Set lightColor and darkColor to #4460FF (previously null)

• Updated docs.json to mirror navigation changes with new "Core" and reorganized "Scene" groups

Documentation Improvements

• Fixed cross-reference links in scene-management.mdx to use full paths (/OpenGeometry/api/...)
• Improved link formatting and capitalization consistency
• Added OUTLINE_TYPE type definition documentation in projection.mdx

Miscellaneous

• Added .gitignore with node_modules/ entry

Implementation Details

The documentation follows the existing Mintlify format with parameter fields, response fields, code examples, and cross-reference cards. The OpenGeometry and Vector3 docs emphasize the initialization dependency (wasm module must be loaded before constructing Vector3), which is a critical constraint for users.

https://claude.ai/code/session_01LfFsmHz67gxarN59GMQYSt