perf(GradientBlinds): defer getBoundingClientRect to rAF on resize

Optimizes `GradientBlinds` layout performance by using `ResizeObserverEntry.contentRect` for immediate renderer resizing and deferring the expensive `getBoundingClientRect()` call (required for mouse interaction mapping) to the next animation frame. This prevents synchronous layout thrashing inside the `ResizeObserver` callback.

- Updates `resize` to accept `ResizeObserverEntry[]`
- Uses `contentRect` for `renderer.setSize`
- Defers `rectRef` update to `requestAnimationFrame`

Co-authored-by: ragusa-it <196988693+ragusa-it@users.noreply.github.com>

src/components/effects/GradientBlinds.tsx

@@ -280,18 +280,36 @@ void main() {
     const mesh = new Mesh(gl, { geometry, program });
     meshRef.current = mesh;
 
-    const resize = () => {
+    const resize = (entries?: ResizeObserverEntry[]) => {
-      const rect = container.getBoundingClientRect();
+      let width, height;
-      rectRef.current = rect;
+
+      if (entries && entries.length > 0) {
+        const entry = entries[0];
+        width = entry.contentRect.width;
+        height = entry.contentRect.height;
+        // Optimization: Defer calling getBoundingClientRect (which forces layout)
+        // to the next frame, since ResizeObserver runs after layout but before paint.
+        requestAnimationFrame(() => {
+          if (rendererRef.current) {
+            rectRef.current = container.getBoundingClientRect();
+          }
+        });
+      } else {
+        const rect = container.getBoundingClientRect();
+        rectRef.current = rect;
+        width = rect.width;
+        height = rect.height;
+      }
+
       if (typeof window !== 'undefined') {
         isMobileRef.current = window.innerWidth <= 768;
         scrollPosRef.current = { x: window.scrollX, y: window.scrollY };
       }
-      renderer.setSize(rect.width, rect.height);
+      renderer.setSize(width, height);
       uniforms.iResolution.value = [gl.drawingBufferWidth, gl.drawingBufferHeight, 1];
 
       if (blindMinWidth && blindMinWidth > 0) {
-        const maxByMinWidth = Math.max(1, Math.floor(rect.width / blindMinWidth));
+        const maxByMinWidth = Math.max(1, Math.floor(width / blindMinWidth));
 
         const effective = blindCount ? Math.min(blindCount, maxByMinWidth) : maxByMinWidth;
         uniforms.uBlindCount.value = Math.max(1, effective);