fix(cesium): enable requestWaterMask for all terrain providers

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: ZTongci

src/engines/Cesium/core/Globe/useTerrainProviderPromise.ts

@@ -54,13 +54,13 @@ function createProvider(type: TerrainType, opts: ProviderOpts): Promise<TerrainP
     case "reearth_terrain":
       return CesiumTerrainProvider.fromUrl(REEARTH_TERRAIN_URL, {
         requestVertexNormals: !!opts.normal,
-        requestWaterMask: false,
+        requestWaterMask: true,
       }) as Promise<TerrainProvider>;
 
     case "cesium": {
       return CesiumTerrainProvider.fromUrl(
         IonResource.fromAssetId(1, { accessToken: opts.ionAccessToken }),
-        { requestVertexNormals: !!opts.normal, requestWaterMask: false },
+        { requestVertexNormals: !!opts.normal, requestWaterMask: true },
       ) as Promise<TerrainProvider>;
     }
 
@@ -71,7 +71,7 @@ function createProvider(type: TerrainType, opts: ProviderOpts): Promise<TerrainP
           IonResource.fromAssetId(parseInt(String(opts.ionAsset), 10), {
             accessToken: opts.ionAccessToken,
           }),
-        { requestVertexNormals: !!opts.normal },
+        { requestVertexNormals: !!opts.normal, requestWaterMask: true },
       ) as Promise<TerrainProvider>;
     }