fix(confusion-matrix): the same exclusion, so silence is not scored as agreement

A run that spent its budget failing preconditions judged some other app than
the one under test, and its quiet checker was being scored as a true negative
against the reviewer.

cmd/internal-tools/confusion-matrix/matrix_test.go

@@ -65,6 +65,15 @@ func TestCrossTabulateScoresEachImplementationIntoOneCell(t *testing.T) {
 			},
 			wantExcluded: missingNoUsableRun,
 		},
+		{
+			name: "every run spent its budget outside the app under test",
+			implementation: fixtureImplementation{
+				Name: "impl-10", Model: "Opus 5",
+				Runs:   []fixtureRun{{Seed: 1, PreconditionFailures: 380}},
+				Review: &fixtureReview{Overall: overallNotDefective},
+			},
+			wantExcluded: missingNoUsableRun,
+		},
 		{
 			name: "no verdict was filed",
 			implementation: fixtureImplementation{