⚡ Bolt: Optimize Zustand selectors and Konva rendering

[sourabhrajcodes]

💡 What: Refactored Zustand usage to use granular selectors instead of state destructuring, and wrapped ElementWrapper in React.memo(). Added inline documentation for these changes.
🎯 Why: Destructuring the entire Zustand state object caused components to re-render unnecessarily when unrelated state changed. Rendering Konva components without memoization caused O(N) re-renders for every canvas element update.
📊 Impact: Eliminates unnecessary re-renders of the Sidebar, Toolbar, and CanvasArea components. Drastically reduces CPU time and frame drops during drag/drop or selection in documents with many elements.
🔬 Measurement: Use React DevTools Profiler to observe component renders. Unrelated state changes no longer trigger renders in these components, and moving a single element no longer triggers a render for all other elements on the canvas.

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PR created automatically by Jules for task 17497330088753774832 started by @sourabhrajcodes

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