Implement WebGL page reserve navigation

public/js/game-loop-module.js

@@ -54,7 +54,9 @@ class GameLoopModule extends BaseModule {
             'requestStartGame',
             'requestSaveGame',
             'requestLoadGame',
-            'resetClientPlaybackAndDisplay'
+            'resetClientPlaybackAndDisplay',
+            'getWebGLBookState',
+            'applyWebGLBookState'
         ]);
     }
 
@@ -322,6 +324,7 @@ class GameLoopModule extends BaseModule {
             if (typeof storyHistory.saveSlot === 'function') {
                 await storyHistory.saveSlot(this.autoSaveSlot, {
                     inkState: null,
+                    webglBookState: this.getWebGLBookState(),
                     choices: [],
                     inputMode: 'none',
                     running: false
@@ -347,6 +350,7 @@ class GameLoopModule extends BaseModule {
             if (!isCurrentOperation()) return;
             await storyHistory.saveSlot(this.autoSaveSlot, {
                 inkState: response.savedState,
+                webglBookState: this.getWebGLBookState(),
                 choices: [],
                 inputMode: 'none',
                 running: true
@@ -372,6 +376,7 @@ class GameLoopModule extends BaseModule {
                     latestRenderedBlockId: storyHistory.latestRenderedBlockId || 0,
                     renderedLineCount: storyHistory.renderedLineCount || 0,
                     musicState: audioManager?.getMusicState?.() || null,
+                    webglBookState: this.getWebGLBookState(),
                     choices: this.currentChoices,
                     inputMode: this.currentInputMode,
                     running: this.gameState.started && !this.gameState.ended
@@ -453,6 +458,7 @@ class GameLoopModule extends BaseModule {
                 browserSave.renderedLineCount || 0
             );
         }
+        this.applyWebGLBookState(browserSave.webglBookState);
         const uiController = this.getModule('ui-controller');
         if (browserSave && uiController?.displayHandler?.restoreFromHistory) {
             await uiController.displayHandler.restoreFromHistory(browserSave);
@@ -516,6 +522,17 @@ class GameLoopModule extends BaseModule {
         }
     }
 
+    getWebGLBookState() {
+        return window.WebGLBookPreferenceBridge?.getBookState?.()
+            || window.BookLabDebug?.getBookState?.()
+            || null;
+    }
+
+    applyWebGLBookState(state = null) {
+        if (!state || typeof state !== 'object') return;
+        window.WebGLBookPreferenceBridge?.applyBookState?.(state);
+    }
+
     hasUnrenderedHistory(browserSave) {
         return Boolean(browserSave) &&
             Number(browserSave.latestBlockId || 0) > Number(browserSave.latestRenderedBlockId || 0);
@@ -565,6 +582,7 @@ class GameLoopModule extends BaseModule {
                 latestRenderedBlockId: storyHistory.latestRenderedBlockId || 0,
                 renderedLineCount: storyHistory.renderedLineCount || 0,
                 musicState: audioManager?.getMusicState?.() || null,
+                webglBookState: this.getWebGLBookState(),
                 choices: this.currentChoices,
                 inputMode: this.currentInputMode,
                 running: this.gameState.started && !this.gameState.ended