fix: ensure terrainProvider is applied on initial mount via direct ref

[ZTongci]

Problem

When the Globe component mounts with terrain already enabled — as happens on navigation-back where Apollo cache delivers data synchronously — globe.terrainProvider is never updated from the default EllipsoidTerrainProvider. Terrain tiles never load even though the CesiumTerrainProvider Promise resolves correctly.

Root Cause

Resium's useCesiumComponent applies props (including terrainProvider) through the component's update() function, which is gated behind an internal C.current flag. That flag is set to true by a passive useEffect. However, the initializer I() runs in a microtask (scheduled from useLayoutEffect), which fires before passive effects. So Globe.update() is always skipped on initial mount (C.current === false).

On first page load this is harmless: a workaround in the visualizer layer forced terrain disabled → enabled after a setTimeout(0), producing a prop change that fires after C.current is already true. On navigation-back, Apollo cache delivers scene data synchronously, so setTimeout(0) fires before the Cesium Viewer has recreated its scene and before Globe has mounted as a React child. Globe mounts with terrain already enabled, no subsequent prop change ever occurs, and globe.terrainProvider is never set.

Fix

Add a useEffect in Globe/index.tsx that holds a CesiumComponentRef to the underlying Cesium Globe object. Once providerPromise resolves, it directly sets globe.terrainProvider on the Cesium element, bypassing Resium's update() timing entirely.

[Copilot]

Pull request overview

This PR fixes an initial-mount timing gap where Resium may skip applying terrainProvider to the Cesium Globe when terrain is already enabled at mount time (e.g., navigation-back with synchronous Apollo cache data), leaving the globe stuck on the default EllipsoidTerrainProvider.

Changes:

• Introduces a direct CesiumComponentRef to access the underlying Cesium Globe instance.
• Adds an effect that, once the terrain provider promise resolves, assigns globe.terrainProvider directly to bypass Resium’s initial update() gating.

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[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

[bnimit]

LGTM!