chore: remove eslint warnings and cleanup unused variables

[VaishnaviP-06]

Tech Debt: Minor Linting and React Hook Warnings

##Issue No. #171

What was wrong

A codebase scan identified a few minor linting and code hygiene issues across the frontend and backend. These issues did not affect functionality but produced unnecessary ESLint warnings and included one technically incorrect React usage.

Changes Made

Frontend

• Removed the unnecessary await before checkInWishlist() inside the useEffect in ProductCard.jsx.
• checkInWishlist() is a synchronous array lookup using .some(), so awaiting it was unnecessary and misleading.

Backend

• Renamed unused catch variables in product.controller.js image-upload error handlers.
• Renamed the unused catch variable in authMiddleware.js.
• Renamed the unused next parameter to _next in errorMiddleware.js while preserving Express error-handler behavior.

Files Changed

• FRONTEND/src/components/ui/ProductCard.jsx
• BACKEND/controllers/product.controller.js
• BACKEND/middleware/authMiddleware.js
• BACKEND/middleware/errorMiddleware.js

Testing

• Verified checkInWishlist() is called synchronously.
• Verified wishlist functionality continues to work correctly.
• Verified no behavioral changes to product creation, update, authentication, or error handling.

[vercel]

@VaishnaviP-06 is attempting to deploy a commit to the niharika-mente's projects Team on Vercel.

A member of the Team first needs to authorize it.

[Aamod-Dev]

The searchProducts function has a broken try/catch structure. The try body is at wrong indentation and the braces don't align with the function scope, creating orphaned catch block.

Fix: Rebase and ensure proper brace matching in searchProducts.

[VaishnaviP-06]

The searchProducts function has a broken try/catch structure. The try body is at wrong indentation and the braces don't align with the function scope, creating orphaned catch block.

Fix: Rebase and ensure proper brace matching in searchProducts.

Okay Noted!!

[Aamod-Dev]

Request Changes

• getRelatedProducts references targetTags (undefined), should be targetTagsSet.
• getProductBundle function body has broken structure — code appears as loose statements outside the function.
• Title says lint cleanup but includes a massive controller refactor. Keep scope focused.

[Aamod-Dev]

Scope exceeds lint cleanup, bugs found

[VaishnaviP-06]

Scope exceeds lint cleanup, bugs found

okay i'll check again and do the changes

[Aamod-Dev]

Looks good, approved!

[Aamod-Dev]

Needs changes: There are merge conflicts. Please resolve them.

[VaishnaviP-06]

Hi @aamod,
I've resolved the merge conflicts and pushed the updates from my side. Could you please take another look at the PR when you have time? Let know if there is any error left by chance.
Thanks!

[Aamod-Dev]

Code fixes are solid: targetTagsSet bug fixed, bundle null safety added, proper Cloudinary cleanup on failure, consistent AppError pattern. LGTM.