Add OGWedge primitive and three.js Wedge shape support

[aka-blackboots]

Motivation

• Provide a new wedge primitive consistent with existing solids (cuboid, cylinder) so kernel users can create wedge solids and project them to 2D.
• Expose wedge to the Three.js integration so UI/visualization code can construct and render wedge geometry from the kernel.

Description

• Add a new kernel primitive OGWedge with center, width, height, and depth, BRep construction, triangulation-based geometry serialization, and outline serialization (main/opengeometry/src/primitives/wedge.rs).
• Register the primitive in the kernel exports (pub mod wedge in main/opengeometry/src/lib.rs).
• Add scene manager plumbing: add_wedge_to_scene_internal and wasm-bindgen bindings addWedgeToScene and addWedgeToCurrentScene in main/opengeometry/src/scenegraph.rs so wedges can be added to scenes like other primitives.
• Update the kernel example pdf_primitives_all to construct a wedge and export its projected PDF (*_wedge.pdf), and add a Wedge wrapper in opengeometry-three plus export it from the shapes index (main/opengeometry-three/src/shapes/wedge.ts and main/opengeometry-three/src/shapes/index.ts).
• Add a concise handoff note at AI-DOCs/opengeometry/2026-03-01-wedge-shape-support.md describing changes and local test instructions.

Testing

• Ran cd main/opengeometry && cargo fmt and it completed successfully.
• Ran cd main/opengeometry && cargo check and it completed successfully.
• Ran cd main/opengeometry && cargo test and all unit tests passed.
• Executed the example with cd main/opengeometry && cargo run --example pdf_primitives_all -- wedge_demo which completed and generated the wedge example PDF (e.g. wedge_demo_wedge.pdf).
• npm run build-core failed in this environment because wasm-pack is not installed, and npm run build-three failed because main/opengeometry/pkg/opengeometry (wasm bindings) is not present until wasm-pack produces them; these are environment limitations rather than functional regressions.
• npm run lint:check reported pre-existing lint issues in the three package (main/opengeometry-three/src/utils/event.ts and a console usage warning in polygon.ts) which are unrelated to the wedge code.

---

Codex Task