Refactor contracts for advanced exploit protection

[Nitya-003]

🧩 Problem

As CropChain adds "Marketplace" features (buying/selling batches), we become vulnerable to Reentrancy attacks and Flash-loan price manipulation. If a malicious actor can re-enter a "withdraw" function, they could drain the Mandi's liquidity.

✨ Proposed Change

Perform a deep security refactor of the smart contract suite to implement enterprise-grade protection patterns.

Technical Requirements:

1. Check-Effect-Interaction (CEI): Refactor every state-changing function to follow the CEI pattern strictly.
2. Reentrancy Guards: Implement ReentrancyGuard from OpenZeppelin on all external-facing functions.
3. Oracle Hardening: If we use prices for crops, implement Time-Weighted Average Prices (TWAP) to prevent flash-loan manipulation of crop values.
4. Emergency Stop: Implement a "Circuit Breaker" (Pausable) that the Admin can trigger if an exploit is detected.

✅ Acceptance Criteria

• Zero vulnerabilities found during a slither or mythril static analysis scan.
• Successful "Mock Attack" test cases (simulating reentrancy) that the contract successfully blocks.
• Documentation of the security architecture in /docs/security.md.

🛠️ Implementation Hint

Use Slither for automated vulnerability detection and Hardhat-Tracer to visualize internal calls during your exploit tests.

[surajsbhoj0101]

assign me please

[Nitya-003]

@surajsbhoj0101 Are you from Apertre 3.0 or DSCWoC?

[surajsbhoj0101]

Apertre 3.0

[Nitya-003]

@Nitya-003 Any updates?

[surajsbhoj0101]

It will be completed by tomorrow