Contract: Implement Non-Transferable Loan NFT Restrictions (SBT Mode)

[ONEONUORA]

📌 Target Component

contracts/loan-nft/src/lib.rs

📝 Description

Loan NFTs can currently be transferred between arbitrary wallet addresses, bypassing collateral ownership verification.

📋 Implementation Requirements

1. Restrict NFT transfer function to only allow transfer to lending contract vault during liquidation or repayment.
2. Revert arbitrary wallet-to-wallet transfer attempts with Error::TokenNonTransferable.

🎯 Testnet Goal

Prevent unauthorized loan position transfers on testnet.

[benedict-cmd]

@benedict-cmd has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hey I am a developer please assign me to this issue and I'll deliver more than expected

ℹ️ Repo Maintainers: To accept this application, review their application or assign @benedict-cmd to this issue.

[glorious21-coder]

@glorious21-coder has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hi! I can complete this task efficiently while ensuring a high-quality implementation. I'd be glad to take ownership of it.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @glorious21-coder to this issue.