fix: restore smallest-area fallback and exclude decorative overlays from index

The bugbot-driven change from smallest-area to first-valid (topmost)
in the fallback path reintroduced the original "stuck on decorative
overlay" bug. Decorative overlay divs (positioned, empty, transparent)
are topmost in elementsFromPoint results, so taking the first valid
element returns the overlay instead of the content underneath.

Fallback path: restored smallest-area selection. elementsFromPoint
returns in z-order; smallest-area naturally skips large overlays in
favor of specific content elements. Handles modals correctly because
modal content elements are smaller than background content at the
same point.

Prehit path: exclude positioned elements with no children and no text
from the R-tree. These are decorative hover-effect divs that should
never be selection targets. The stacking-order sort then operates only
on meaningful content elements.

Author: aidenybai

packages/react-grab/src/utils/element-at-point-index.ts

@@ -47,7 +47,13 @@ export const buildElementAtPointIndex = (): void => {
         const boundingRect = entry.boundingClientRect;
         if (boundingRect.width === 0 || boundingRect.height === 0) continue;
         if (!isValidGrabbableElement(targetElement)) continue;
-        if (getComputedStyle(targetElement).position === "fixed") continue;
+        const computedPosition = getComputedStyle(targetElement).position;
+        if (computedPosition === "fixed") continue;
+        if (
+          (computedPosition === "absolute" || computedPosition === "sticky") &&
+          targetElement.childElementCount === 0 &&
+          (targetElement.textContent?.trim().length ?? 0) === 0
+        ) continue;
 
         accumulatedElements.push({
           element: targetElement,

packages/react-grab/src/utils/get-element-at-position.ts

@@ -86,12 +86,16 @@ export const getElementAtPosition = (clientX: number, clientY: number): Element
 
   const elementsAtPoint = document.elementsFromPoint(clientX, clientY);
   let result: Element | null = null;
+  let smallestArea = Infinity;
 
   for (const candidateElement of elementsAtPoint) {
     if (!isValidGrabbableElement(candidateElement)) continue;
-    if (getElementArea(candidateElement) === 0) continue;
-    result = candidateElement;
-    break;
+    const area = getElementArea(candidateElement);
+    if (area === 0) continue;
+    if (area < smallestArea) {
+      smallestArea = area;
+      result = candidateElement;
+    }
   }
 
   scheduleResume();