[Feature]: Implement auction bid logic (backend)

[04shubham7]

So, what is it about?

Add API logic for placing bids with increments of ₹100, auction expiry after 48 hours, and ability for sellers to accept current highest bid.

Code of Conduct

• I agree to follow this project's Code of Conduct

[pranjalarora98]

@04shubham7 can u plz assign me this issue!

[LONECODER1]

@04shubham7 assign it to me

Description

Add API logic for placing bids with increments of ₹100, automatic auction expiry after 48 hours, and functionality for sellers to accept the current highest bid.

Steps to Implement

1. Create Bid Model — include fields like bidAmount, bidderId, productId, and timestamp.
2. Implement Bid Placement API — allow users to place bids only in ₹100 increments above the current highest bid.
3. Set Auction Expiry — automatically close the auction 48 hours after creation using a timestamp or background job.
4. Add Seller Acceptance Endpoint — enable sellers to accept the current highest bid before expiry.
5. Update Product/Auction Status — mark item as “sold” or “expired” once accepted or expired.

Expected Outcome

Bidding system where users can place valid bids, auctions auto-expire in 48 hours, and sellers can finalize sales by accepting top bids.

[04shubham7]

@LONECODER1 updates?

[LONECODER1]

Will submit by tonight