chore: interface update (#79)

Co-authored-by: zerosnacks <95942363+zerosnacks@users.noreply.github.com>

Author: github-actions[bot]

src/interfaces/IFeeManager.sol

@@ -19,4 +19,6 @@ interface IFeeManager is IFeeAMM {
     function userTokens(address) external view returns (address);
 
     function validatorTokens(address) external view returns (address);
+
+    function getFeeToken() external view returns (address);
 }

src/interfaces/ITIP20.sol

@@ -237,4 +237,22 @@ interface ITIP20 {
     /// @param account The address to query pending rewards for.
     /// @return The total pending claimable reward amount.
     function getPendingRewards(address account) external view returns (uint256);
+
+    // EIP-2612 Permit (TIP-1004)
+
+    /// @notice The permit signature has expired (block.timestamp > deadline)
+    error PermitExpired();
+
+    /// @notice The permit signature is invalid (wrong signer, malformed, or zero address recovered)
+    error InvalidSignature();
+
+    /// @notice Approves `spender` to spend `value` tokens on behalf of `owner` via a signed permit
+    function permit(address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s)
+        external;
+
+    /// @notice Returns the current nonce for an address
+    function nonces(address owner) external view returns (uint256);
+
+    /// @notice Returns the EIP-712 domain separator for this token
+    function DOMAIN_SEPARATOR() external view returns (bytes32);
 }