⚡ Bolt: Optimize derived state calculation in notifications

[sshahriazz]

💡 What: Refactored NotificationMenu and NotificationTabPanel to use useMemo instead of useState + useEffect for categorizing notifications into today and older groups.

🎯 Why: Using an effect to map/reduce props into local state causes an unnecessary double-render cycle. The first render shows the initial state (empty arrays), the effect runs, sets the state, and triggers a second render with the derived data. This wastes CPU cycles and can cause layout shifts.

📊 Impact: Reduces re-renders by 50% for these components when they mount or when notificationsData changes. The calculation now happens synchronously during the render phase.

🔬 Measurement: Verify by mounting the components or updating the notification data; React DevTools will show one render pass instead of two.

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PR created automatically by Jules for task 3134937155069941456 started by @sshahriazz

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