result: clean up test-to-requirement traceability #554

Apply the test-to-requirement traceability clean-up described in #522 to the Result component (score/result/).

Review every C++ gtest against the current comp_req__result__... needs. Add mandated FullyVerifies or PartiallyVerifies links, TestType, DerivationTechnique, and self-contained Description metadata where a test genuinely verifies a requirement. Reconcile requirement text and test behavior in both directions, and leave non-functional requirements that are verifiable only by inspection without artificial test coverage.