Replace Three.js globe with Cesium

Migrate the globe view to a Cesium viewer with Esri satellite
imagery and terrain, dropping the custom blue-marble texture and
dot-bead rendering. Add vite-plugin-cesium and a container element
for the viewer.

Also rework the binder leather and suede materials with dedicated
normal maps, and refine timeline labels and page hole sizing.

package.json

@@ -10,11 +10,13 @@
     "preview": "vite preview"
   },
   "dependencies": {
+    "cesium": "^1.145.0",
     "three": "^0.170.0"
   },
   "devDependencies": {
     "pngjs": "^7.0.0",
     "puppeteer-core": "^25.11.0",
-    "vite": "^6.0.0"
+    "vite": "^6.0.0",
+    "vite-plugin-cesium": "^1.2.23"
   }
 }