fix: support orthographic coordinates in PathMarkerLayer

[ibgreen-openai]

Summary

• allow PathMarkerLayer to project meter-offset positions even when the viewport does not expose metersToLngLatDelta, letting the layer work in orthographic and other non-geospatial views
• add an example (examples/layers/path-marker-orthographic) that renders PathOutlineLayer and PathMarkerLayer inside an OrthographicView, and surface it on the website
• silence an import/no-unresolved false positive in SegmentsLayer

Testing

• yarn lint
• yarn test (fails: Running target test for 11 projects failed - @deck.gl-community/template:test)

---

https://chatgpt.com/codex/tasks/task_i_68a4a816d414832cb60f0729a0c27279