feat: Add authorizedTraders mapping and minimum flash loan amount safeguard

[malgus01]

PR Description

Summary

This PR introduces two important safety and access-control mechanisms in TestArbitrage.sol:

1. An authorizedTraders mapping for whitelisting addresses that can execute trades.
2. A configurable minFlashAmount threshold to prevent dust-level flash loan requests.

Both additions are documented with NatSpec comments for clarity and maintainability.

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Changes

• Authorized Traders Mapping

  • Added mapping(address => bool) public authorizedTraders;
  • Restricts execution of trade logic to only approved addresses.
  • Provides flexibility for controlled testing and production scenarios.

• Minimum Flash Loan Amount

  • Introduced uint256 public minFlashAmount = 1000;
  • Ensures flash loan requests below this threshold are disallowed.
  • Protects against dust attacks and avoids unprofitable transactions.

• Documentation

  • Added NatSpec comments for both features (authorizedTraders and minFlashAmount).

• Formatting

  • Ran forge fmt to maintain code consistency.

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Rationale

• Access Control:
  Without restrictions, any address could potentially trigger arbitrage logic, which introduces security and testing risks. Whitelisting ensures only trusted accounts can interact.

• Economic Safety:
  Very small flash loans can waste gas and pose potential DoS risks. Enforcing a minimum flash loan amount improves efficiency and safety.

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Impact

• No breaking changes to existing deployment or logic.
• Future contracts or tests may rely on authorizedTraders to enforce role-based permissions.
• minFlashAmount provides a configurable safety net but does not alter higher-level arbitrage logic.

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Next Steps

• Implement functions for:
  • Adding/removing authorizedTraders.
  • Updating minFlashAmount dynamically via governance or owner functions.
• Integrate these checks into trade execution and flash loan entry points.
• Extend test coverage for:
  • Unauthorized access attempts.
  • Flash loans below the minimum threshold.