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.

src/textures/pages.js

@@ -9,7 +9,7 @@ export const TEX_W = 768;
 export const TEX_H = 1075;
 export const HOLE_U = [0.085, 0.24, 0.4, 0.56, 0.72, 0.855]; // 活页孔（自顶部归一化）
 export const HOLE_X = 0.065;         // 孔中心相对页内缘（环前交点 0.085 − 页缘空隙 0.02）
-export const HOLE_R = 0.052;        // 孔半径（世界）
+export const HOLE_R = 0.03;         // 孔半径（世界，略大于环丝，留出穿环空隙）
 
 const SERIF = '"Noto Serif SC","Songti SC","STSong","SimSun",Georgia,serif';
 const KAI = '"Kaiti SC","STKaiti","KaiTi","Noto Serif SC",serif';