fix(iOS, Tabs): resolve content scroll view for tabBarMinimizeBehavior in real-world RN hierarchies

ios/RNSScreen.mm

@@ -1538,6 +1538,25 @@ - (void)viewDidDisappear:(BOOL)animated
   _shouldNotify = YES;
 }
 
+// See RNSTabsScreenViewController: when a tab hosts a nested stack, UIKit may
+// resolve the bottom-edge content scroll view (which drives iOS 26
+// `tabBarMinimizeBehavior`) against the visible stack screen's view
+// controller rather than the tab root. UIKit's automatic detection cannot
+// reach UIScrollViews nested in a React Native screen tree, so fall back to a
+// breadth-first search. Restricted to the bottom edge so top-edge
+// (navigation bar) resolution is unaffected.
+- (UIScrollView *)contentScrollViewForEdge:(NSDirectionalRectEdge)edge
+{
+  UIScrollView *scrollView = [super contentScrollViewForEdge:edge];
+  if (scrollView != nil) {
+    return scrollView;
+  }
+  if (edge == NSDirectionalRectEdgeBottom) {
+    return [RNSScrollViewFinder findScrollViewBreadthFirstFrom:self.view];
+  }
+  return nil;
+}
+
 - (void)viewDidLayoutSubviews
 {
   [super viewDidLayoutSubviews];

ios/helpers/scroll-view/RNSScrollViewFinder.h

@@ -25,4 +25,18 @@
  */
 + (nullable UIScrollView *)findContentScrollViewWithDelegatingToProvider:(nullable UIView *)view;
 
+/**
+ * Breadth-first search for the first vertically-scrollable UIScrollView
+ * descendant. Unlike the first-descendant-chain walk, this finds scroll views
+ * in real-world screen trees (styled wrapper views, headers, virtualized
+ * lists such as FlashList/LegendList, nested stack navigators), which
+ * UIKit's automatic content-scroll-view detection cannot reach.
+ * Horizontal-only scrollers (e.g. carousels) are skipped, so behaviors driven
+ * by the result (such as `tabBarMinimizeBehavior`) track vertical scrolling.
+ * The search is bounded so a pathological tree cannot stall the main thread.
+ *
+ * When `view == nil`, it returns `nil`.
+ */
++ (nullable UIScrollView *)findScrollViewBreadthFirstFrom:(nullable UIView *)view;
+
 @end

ios/helpers/scroll-view/RNSScrollViewFinder.mm

@@ -41,4 +41,37 @@ + (nullable UIScrollView *)findContentScrollViewWithDelegatingToProvider:(nullab
   return nil;
 }
 
++ (nullable UIScrollView *)findScrollViewBreadthFirstFrom:(nullable UIView *)view
+{
+  if (view == nil) {
+    return nil;
+  }
+
+  static const NSUInteger kMaxVisitedViews = 2000;
+  NSMutableArray<UIView *> *queue = [NSMutableArray arrayWithObject:view];
+  NSUInteger index = 0;
+
+  while (index < queue.count && queue.count < kMaxVisitedViews) {
+    UIView *current = queue[index++];
+
+    if ([current isKindOfClass:UIScrollView.class]) {
+      UIScrollView *scrollView = static_cast<UIScrollView *>(current);
+      // Skip horizontal-only scrollers (carousels). Unmeasured scroll views
+      // (zero contentSize) pass, since the main list may not be laid out yet
+      // when UIKit first resolves the content scroll view.
+      BOOL isHorizontalOnly = scrollView.contentSize.width > scrollView.bounds.size.width &&
+          scrollView.contentSize.height <= scrollView.bounds.size.height;
+      if (!isHorizontalOnly) {
+        return scrollView;
+      }
+      // Do not descend into a skipped horizontal scroller.
+      continue;
+    }
+
+    [queue addObjectsFromArray:current.subviews];
+  }
+
+  return nil;
+}
+
 @end

ios/tabs/screen/RNSTabsScreenViewController.mm

@@ -105,6 +105,26 @@ - (bool)tabScreenSelectedRepeatedly
   return false;
 }
 
+// UIKit resolves the scroll view that drives `tabBarMinimizeBehavior`
+// (iOS 26 tab-bar minimize + inline bottom accessory) by asking the selected
+// tab's view controller for its bottom-edge content scroll view. UIKit's
+// automatic detection cannot find UIScrollViews nested inside a typical
+// React Native screen tree (styled wrappers, headers, virtualized lists,
+// nested stack navigators), so minimize never engages. Fall back to a
+// breadth-first search of the currently attached content. Restricted to the
+// bottom edge so top-edge (navigation bar) resolution is unaffected.
+- (UIScrollView *)contentScrollViewForEdge:(NSDirectionalRectEdge)edge
+{
+  UIScrollView *scrollView = [super contentScrollViewForEdge:edge];
+  if (scrollView != nil) {
+    return scrollView;
+  }
+  if (edge == NSDirectionalRectEdgeBottom) {
+    return [RNSScrollViewFinder findScrollViewBreadthFirstFrom:self.view];
+  }
+  return nil;
+}
+
 #if !TARGET_OS_TV
 
 - (RNSOrientation)evaluateOrientation