ContractUnpaired

A current contract that could not be paired with a baseline one (#200): no baseline contract has the same (serialName, base) identity, and its bare serial name is shared by several contracts on at least one side (e.g. a pre-base-identity baseline recorded one bare created while the current snapshot has OrderEvent/created and UserEvent/created). Pairing by guess could diff the wrong bodies, and calling it added/removed would be false, so — like a CoverageGap — it is surfaced as unverified. contract is the qualified display name.