perf: cut ControlApp re-renders and lazy-load VFX packs

Move audio scrub/volume and brush drafts off root React ticks, coalesce overlay layout IPC, cache machine fingerprint and asset URLs, share one scene overlay host, and stop idle Pixi ticker. Also harden console against EPIPE on window load failures.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/renderer/shared/PresentationView.tsx

@@ -12,6 +12,7 @@ import { MaterialOverlay } from './materials/MaterialOverlay';
 import { useMaterialsOverlayState } from './materials/useMaterialsOverlayState';
 import { NpcsSceneOverlay } from './npcs/NpcsSceneOverlay';
 import { useNpcsOverlayState } from './npcs/useNpcsOverlayState';
+import { SceneOverlayHost } from './sceneOverlay/SceneOverlayHost';
 import styles from './PresentationView.module.css';
 import { RotatedImage } from './RotatedImage';
 import { useAssetUrl } from './useAssetImageUrl';
@@ -164,13 +165,16 @@ export function PresentationView({
       {showEffects && scene?.previewAssetType === 'image' && scene.darkenScene && contentRect ? (
         <SceneDarknessOverlay state={sdState} overlayAlpha={1} viewport={contentRect} />
       ) : null}
-      {activeMaterial ? (
-        <MaterialOverlay
-          assetId={activeMaterial.assetId}
-          layout={materialsOverlay?.layout ?? DEFAULT_MATERIALS_OVERLAY_LAYOUT}
-        />
-      ) : null}
-      {activeNpcItems.length > 0 ? <NpcsSceneOverlay items={activeNpcItems} /> : null}
+      <SceneOverlayHost active={Boolean(activeMaterial) || activeNpcItems.length > 0}>
+        {activeMaterial ? (
+          <MaterialOverlay
+            embedded
+            assetId={activeMaterial.assetId}
+            layout={materialsOverlay?.layout ?? DEFAULT_MATERIALS_OVERLAY_LAYOUT}
+          />
+        ) : null}
+        {activeNpcItems.length > 0 ? <NpcsSceneOverlay embedded items={activeNpcItems} /> : null}
+      </SceneOverlayHost>
       {showTitle ? (
         <div className={styles.titleWrap}>
           <div className={compact ? styles.titleCompact : styles.titleFull}>