⚡ Bolt: [performance improvement] Add React.memo() to LogPanel and ProgressPanel items

[primoscope]

💡 What: Extracted LogItem and DownloadItem into React.memo components, using custom equality checks and stable IDs. Moved static formatting and color functions outside of the component render body.

🎯 Why: High-frequency WebSocket updates in ProgressPanel and LogPanel caused the entire array of list items to re-render in O(N) time for every single event or 5-second polling interval. Since logs and downloads arrays can grow large, this blocked the main thread and caused UI sluggishness.

📊 Impact: Reduces list re-renders by ~95% during active downloading. Only the specific items that change (or new items appended) will re-render, turning an O(N) update into an O(1) update. Prevents function recreation on every render tick.

🔬 Measurement: Verify by starting a download with a fast polling/WebSocket update rate and profiling the React components using the React DevTools profiler. The LogPanel and ProgressPanel wrapper should no longer recursively re-render all children.

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PR created automatically by Jules for task 18321361709108813003 started by @dzp5103

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