📝 Add docstrings to codex/add-client-side-logic-to-viewer3d

Docstrings generation was requested by @shayancoin.

* #15 (comment)

The following files were modified:

* `frontend/src/app/components/viewer3d.tsx`

Author: coderabbitai[bot]

frontend/src/app/components/viewer3d.tsx

@@ -14,6 +14,14 @@ declare global {
   }
 }
 
+/**
+ * Render a GLTF/GLB model and signal when its primary scene becomes visible.
+ *
+ * Resolves a provided model URL to an absolute URL when running in a browser, loads the GLTF, and renders its scene as a primitive. After the scene is available, schedules a single animation frame that records the visibility timestamp on `window.__lod0VisibleAt` and dispatches a `CustomEvent` named `"lod0:visible"` with `{ ts }` in `event.detail`.
+ *
+ * @param modelUrl - The model file URL (absolute or relative). Relative URLs are resolved against `window.location.origin` when available.
+ * @returns A JSX element that renders the loaded GLTF scene.
+ */
 function Model({ modelUrl }: { modelUrl: string }) {
   // Resolve absolute URL to avoid base path issues
   const src = useMemo(() => {