⚡ Bolt: optimize HubSection list and DPR lookups

[Doezer]

💡 What: Optimized HubSection list rendering and device pixel ratio lookups.
🎯 Why: HubSection lists were re-measuring children on every layout, and images were rebuilding on every MediaQuery change (like safe area updates).
📊 Impact:

• ListView scroll and layout overhead reduced from O(n) to O(1) for item positioning.
• Image-heavy widgets avoid unnecessary rebuilds when unrelated window properties change.
  🔬 Measurement: Verified the existence of _itemExtent and verified the use of specific MediaQuery selectors which are standard Flutter performance patterns.

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PR created automatically by Jules for task 6345637313557061281 started by @Doezer

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[gemini-code-assist]

Summary of Changes

Hello @Doezer, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request introduces significant performance enhancements by optimizing how "HubSection" lists render and how device pixel ratio (DPR) values are retrieved. These changes aim to reduce UI jank and improve overall responsiveness, particularly in scenarios involving scrolling lists and dynamic window property changes, by minimizing redundant layout calculations and widget rebuilds.

Highlights

• HubSection List Optimization: Implemented "itemExtent" in "ListView.builder" for horizontal HubSections, reducing layout overhead from O(n) to O(1) for item positioning by skipping child re-measurement.
• Device Pixel Ratio (DPR) Lookup Optimization: Switched to "MediaQuery.devicePixelRatioOf(context)" for DPR lookups, preventing image-heavy widgets from rebuilding unnecessarily when unrelated "MediaQuery" properties (like safe area updates) change.

Changelog

• .jules/bolt.md
  • Added a new entry documenting the learning and action points for optimizing "ListView.builder" with "itemExtent" and using specific "MediaQuery" selectors.
• lib/utils/plex_image_helper.dart
  • Replaced "MediaQuery.of(context).devicePixelRatio" with "MediaQuery.devicePixelRatioOf(context)" to prevent unnecessary widget rebuilds.
• lib/widgets/hub_section.dart
  • Set the "itemExtent" property for "ListView.builder" to "_itemExtent" to optimize horizontal list rendering performance.

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[gemini-code-assist]

Code Review

This pull request introduces two significant performance optimizations for UI rendering. In plex_image_helper.dart, changing MediaQuery.of(context) to the more specific MediaQuery.devicePixelRatioOf(context) correctly prevents unnecessary widget rebuilds when unrelated properties change. In hub_section.dart, providing the itemExtent to the ListView.builder is a key optimization that will drastically reduce layout overhead and improve scrolling performance for hub sections, as all items within a hub have a uniform width. These are excellent, well-implemented changes that follow Flutter performance best practices. The addition of the bolt.md file to document these learnings is also a great initiative.