[WP-M8] totalUnderlyingMinusSponsored() may revert on underflow and malfunction the contract

Handle WatchPug Vulnerability details function totalUnderlyingMinusSponsored public view returns uint256 // TODO no invested amount yet return totalUnderlying - totalSponsored; As a function that many other functions depended on, totalUnderlyingMinusSponsored can revert on underflow when...