⚡ Bolt: optimize HubSection list and DPR lookups

.jules/bolt.md

@@ -0,0 +1,3 @@
+## 2025-05-15 - [Optimize HubSection list and DPR lookups]
+**Learning:** Providing `itemExtent` to `ListView.builder` for horizontal hubs with uniform items drastically reduces layout overhead. Additionally, using specialized `MediaQuery` selectors like `devicePixelRatioOf(context)` prevents unnecessary global rebuilds on safe area or window size changes.
+**Action:** Always check for fixed-size list items and prefer specific MediaQuery selectors over `MediaQuery.of(context)`.

lib/utils/plex_image_helper.dart

@@ -37,7 +37,9 @@ class PlexImageHelper {
   /// the platform-reported DPR doesn't reflect the true physical density
   /// (common on Linux X11 with compositor scaling).
   static double effectiveDevicePixelRatio(BuildContext context) {
-    final reportedDpr = MediaQuery.of(context).devicePixelRatio;
+    // BOLT OPTIMIZATION: Use specialized MediaQuery selectors to prevent unnecessary rebuilds
+    // when unrelated MediaQuery properties change (e.g. safe area insets).
+    final reportedDpr = MediaQuery.devicePixelRatioOf(context);
     try {
       final displayWidth = View.of(context).display.size.width;
       // Scale quality with display resolution: 1920px = baseline (1.0x)

lib/widgets/hub_section.dart

@@ -414,6 +414,9 @@ class HubSectionState extends State<HubSection> {
                     builder: (scrollController) => ListView.builder(
                       controller: scrollController,
                       scrollDirection: Axis.horizontal,
+                      // BOLT OPTIMIZATION: Use itemExtent to skip child measurement and improve scroll performance.
+                      // All items in this hub have a uniform width of cardWidth + 4px padding.
+                      itemExtent: _itemExtent,
                       padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 5),
                       itemCount: widget.hub.items.length,
                       itemBuilder: (context, index) {