⚡ Bolt: Optimize ScrollSpy with requestAnimationFrame

[google-labs-jules]

• 💡 What: Throttled the scroll event listener in ScrollSpy using requestAnimationFrame.
• 🎯 Why: The previous implementation executed getBoundingClientRect (which forces a reflow) on every scroll event, causing performance degradation during rapid scrolling.
• 📊 Impact: Reduces main-thread work significantly by limiting scroll handler execution to the screen refresh rate (typically 60fps).
• 🔬 Measurement: Can be verified using the Performance tab in DevTools; scroll handler calls will be spaced out by ~16ms instead of firing continuously.

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PR created automatically by Jules for task 11971099211518335023 started by @sshahriazz

[google-labs-jules]

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