Add WebGL book scene checkpoint

public/js/loader.js

@@ -24,7 +24,7 @@ const ModuleState = {
     ERROR: 'ERROR'
 };
 
-const MODULE_CACHE_BUSTER = '20260516-scroll-window';
+const MODULE_CACHE_BUSTER = '20260603-webgl-right-page-text';
 window.MODULE_CACHE_BUSTER = MODULE_CACHE_BUSTER;
 
 /**
@@ -113,6 +113,7 @@ const ModuleLoader = (function() {
             { id: 'paragraph-layout', script: '/js/paragraph-layout-module.js', weight: 17 },
             { id: 'sentence-queue', script: '/js/sentence-queue-module.js', weight: 12 },
             { id: 'layout-renderer', script: '/js/layout-renderer-module.js', weight: 13 }, // Add Layout Renderer module
+            { id: 'webgl-book-scene', script: '/js/webgl-book-scene-module.js', weight: 13 },
             { id: 'animation-queue', script: '/js/animation-queue-module.js', weight: 12 },
             { id: 'playback-coordinator', script: '/js/playback-coordinator-module.js', weight: 8 }, // Synchronizes animation + TTS
 
@@ -883,12 +884,18 @@ const ModuleLoader = (function() {
             return;
         }
 
-        await waitForProgressIndicatorsToExit();
+        await Promise.race([
+            waitForProgressIndicatorsToExit(),
+            new Promise(resolve => setTimeout(resolve, 700))
+        ]);
 
         // Set opacity to 0 to trigger the fade-out transition
         loadingOverlay.style.opacity = '0';
 
-        await waitForTransition(loadingOverlay, 'opacity');
+        await Promise.race([
+            waitForTransition(loadingOverlay, 'opacity'),
+            new Promise(resolve => setTimeout(resolve, 700))
+        ]);
 
         console.log('Module Loader: Removing overlay from DOM');