fix: correct vesting schedule boundary and silent ETH transfer failure

src/recovery/Recovery.sol

@@ -43,7 +43,7 @@ contract Recovery is UUPSUpgradeable {
     function withdrawETH(address[] calldata targets, uint256[] calldata amounts) public onlyOwner {
         for (uint256 i = 0; i < targets.length; i++) {
             (bool success,) = targets[i].call{ value: amounts[i] }("");
-            if (!success) continue;
+            require(success, "Recovery: ETH transfer failed");
         }
     }
 }

src/smart-escrow/SmartEscrow.sol

@@ -319,8 +319,12 @@ contract SmartEscrow is AccessControlDefaultAdminRules {
     function _vestingSchedule(uint256 timestamp) internal view returns (uint256) {
         if (timestamp < cliffStart) {
             return 0;
-        } else if (timestamp > end) {
-            return OP_TOKEN.balanceOf({ account: address(this) }) + released;
+        } else if (timestamp >= end) {
+            // Return the total number of tokens that were ever vested, computed from
+            // the schedule parameters, so the value is stable regardless of how many
+            // tokens have already been released and transferred out of this contract.
+            uint256 totalVestingEvents = (end - start) / vestingPeriod;
+            return initialTokens + totalVestingEvents * vestingEventTokens;
         } else {
             return initialTokens + ((timestamp - start) / vestingPeriod) * vestingEventTokens;
         }