⚡ Bolt: [performance improvement] Add React.memo to ProductCard

[Dev22603]

💡 What: Wrapped ProductCard component export in React.memo().

🎯 Why: In Home.jsx, the rapid-updating local state searchQuery triggered severe re-render cascades in all child components, causing unnecessary and expensive re-rendering of the entire product grid on every keystroke.

📊 Impact: This dramatically reduces unnecessary re-renders of the product grid on the home page during search. Now, the ProductCard components will only re-render if their individual properties (or context) actually change, rather than on every single character typed into the search bar.

🔬 Measurement: To verify, one can type quickly into the search input on the Home page. Before this change, rapid typing could feel sluggish due to the heavy grid re-rendering. After this change, the search input response should be noticeably faster because the product grid skips rendering on unrelated state updates.

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PR created automatically by Jules for task 6776565658169851106 started by @Dev22603

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