Stabilize WebGL flip reveal handoff

public/js/book-texture-renderer-module.js

@@ -148,6 +148,9 @@ class BookTextureRendererModule extends BaseModule {
             this.drawSpread(this.currentSpread);
         });
         this.addEventListener(document, 'book-texture:fast-forward', this.fastForwardAnimations);
+        this.addEventListener(document, 'webgl-book:reveal-committed', (event) => {
+            this.completeRevealBlockIds(event.detail?.blockIds || []);
+        });
         this.addEventListener(document, 'ui:command', (event) => {
             if (event.detail?.type === 'continue') this.fastForwardAnimations();
         });
@@ -1081,6 +1084,18 @@ class BookTextureRendererModule extends BaseModule {
         }
     }
 
+    completeRevealBlockIds(blockIds = []) {
+        const ids = Array.isArray(blockIds) ? blockIds : [];
+        ids.forEach((blockId) => {
+            const id = String(blockId ?? '');
+            if (!id) return;
+            const animation = this.activeAnimations.get(id);
+            if (animation) animation.completed = true;
+            this.revealedBlockIds.add(id);
+            this.pendingRevealBlockIds.delete(id);
+        });
+    }
+
     stopAnimations() {
         this.activeAnimations.clear();
         this.pendingRevealBlockIds.clear();