Seed tool treats any message containing [known candidate: as known #55

tools/oracles.cs seeds counts a failing test as a known candidate whenever its message contains [known candidate: anywhere. When one test method checks several rows, and one of them is a registered candidate, a seed that breaks a different row in the same method reads as "known" instead of "caught". So the seed proof can pass without the oracle having caught the seeded defect.

The probing round worked around it by splitting DecorativeElementContractTests into one method per arity. The tool should match per failing line instead, or refuse a mixed message. Seed the case to prove it.