⚡ Bolt: Optimize list views with useMemo and remove unused state

[belpythons]

💡 What:

• Removed unused filteredPosts derived state calculation in Forum.jsx.
• Memoized the externalResources array and the filteredResources derived list in Documentaries.jsx using useMemo.
• Memoized the filteredRoadmaps derived list in Roadmap.jsx using useMemo.
• Added a critical learning to .jules/bolt.md about optimizing or removing derived state in list components.

🎯 Why:

• Unused Computations: The filteredPosts array was being calculated on every render but never used in the UI, wasting CPU cycles.
• Unmemoized Array Filtering: In Documentaries.jsx and Roadmap.jsx, array filtering logic was running on every render. For list views where state like searchTerm or selectedCategory frequently changes, recreating large derived arrays causes unnecessary main thread work. Wrapping these in useMemo ensures they only recalculate when their specific dependencies change.

📊 Impact:

• Reduces Main Thread Blocking: Eliminates unnecessary work (unused computation) and prevents redundant array filtering.
• Improves Responsiveness: Typing into the search input or switching categories will be smoother and less prone to stutter, especially as the list size grows.

🔬 Measurement:

• Observe faster UI updates when typing in the search bar on the Documentaries page or switching tabs on the Roadmap page.
• React DevTools Profiler will show reduced render times for these list components.

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PR created automatically by Jules for task 9126619240565129927 started by @belpythons

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