fix: guard scroll operations against infinite extents

lib/focus/focusable_wrapper.dart

@@ -306,6 +306,7 @@ class _FocusableWrapperState extends State<FocusableWrapper> with SingleTickerPr
         scrollDelta -= (_focusDecorationPadding - projectedItemTop);
       }
 
+      if (!position.maxScrollExtent.isFinite) return;
       final targetOffset = (currentOffset + scrollDelta).clamp(position.minScrollExtent, position.maxScrollExtent);
 
       position.animateTo(targetOffset, duration: const Duration(milliseconds: 200), curve: Curves.easeInOut);

lib/screens/libraries/tabs/library_browse_tab.dart

@@ -998,7 +998,12 @@ class _LibraryBrowseTabState extends BaseLibraryTabState<PlexMetadata, LibraryBr
     final offset = _effectiveTopPadding + targetRow * rowHeight - _chipsBarHeight;
 
     final gen = _jumpScrollGeneration;
-    final clampedOffset = offset.clamp(0.0, _scrollController.position.maxScrollExtent);
+    final maxExtent = _scrollController.position.maxScrollExtent;
+    if (!maxExtent.isFinite) {
+      _isJumpScrolling = false;
+      return;
+    }
+    final clampedOffset = offset.clamp(0.0, maxExtent);
 
     // If a newer jump already superseded this one, skip the animation
     // entirely — the next call will handle the final position.
@@ -1130,6 +1135,7 @@ class _LibraryBrowseTabState extends BaseLibraryTabState<PlexMetadata, LibraryBr
 
     final offset = _scrollController.offset;
     final viewportHeight = _scrollController.position.viewportDimension;
+    if (!viewportHeight.isFinite) return;
     final firstIndex = _itemIndexFromScrollOffset(offset);
 
     final itemWidth = _lastCrossAxisExtent / _currentColumnCount;
@@ -1179,6 +1185,7 @@ class _LibraryBrowseTabState extends BaseLibraryTabState<PlexMetadata, LibraryBr
 
     final offset = _scrollController.offset;
     final viewportHeight = _scrollController.position.viewportDimension;
+    if (!viewportHeight.isFinite) return;
     final firstIndex = _itemIndexFromScrollOffset(offset);
 
     final itemWidth = _lastCrossAxisExtent / _currentColumnCount;
@@ -1254,6 +1261,7 @@ class _LibraryBrowseTabState extends BaseLibraryTabState<PlexMetadata, LibraryBr
 
     final offset = _scrollController.offset;
     final viewportHeight = _scrollController.position.viewportDimension;
+    if (!viewportHeight.isFinite) return;
     final firstVisible = _itemIndexFromScrollOffset(offset);
     final itemWidth = _lastCrossAxisExtent / _currentColumnCount;
     final itemHeight = itemWidth / GridLayoutConstants.posterAspectRatio;

lib/utils/scroll_utils.dart

@@ -23,7 +23,9 @@ void scrollToCurrentItem(ScrollController controller, GlobalKey firstItemKey, in
     if (!controller.hasClients) return;
     final itemHeight = (firstItemKey.currentContext?.findRenderObject() as RenderBox?)?.size.height;
     if (itemHeight == null) return;
-    final target = (currentIndex * itemHeight).clamp(0.0, controller.position.maxScrollExtent);
+    final maxExtent = controller.position.maxScrollExtent;
+    if (!maxExtent.isFinite) return;
+    final target = (currentIndex * itemHeight).clamp(0.0, maxExtent);
     controller.jumpTo(target);
   });
 }
@@ -42,8 +44,10 @@ void scrollListToIndex(
   if (controller.positions.length != 1 || itemExtent <= 0) return;
 
   final viewport = controller.position.viewportDimension;
+  final maxExtent = controller.position.maxScrollExtent;
+  if (!viewport.isFinite || !maxExtent.isFinite) return;
   final targetCenter = leadingPadding + (index * itemExtent) + (itemExtent / 2);
-  final desiredOffset = (targetCenter - (viewport / 2)).clamp(0.0, controller.position.maxScrollExtent);
+  final desiredOffset = (targetCenter - (viewport / 2)).clamp(0.0, maxExtent);
 
   if (animate) {
     controller.animateTo(desiredOffset, duration: const Duration(milliseconds: 150), curve: Curves.easeOut);