{
  "source_id": "P1",
  "distinct_dogs": 4,
  "dog_harness_combinations": 12,
  "baseline_trials": 4,
  "harness_condition_trials": 24,
  "total_trials": 28,
  "distinct_dogs_per_harness": {
    "Fressnapf own-brand": 1,
    "Julius-K9 Duo-Flex": 3,
    "Julius-K9 IDC": 4,
    "Julius-K9 power": 4
  },
  "scope": "Design-count arithmetic only; no experiment rerun or raw gait reanalysis"
}