{
  "authoredScene": {
    "id": "stable string",
    "speakerRole": "learner | guide | challenger",
    "visibleRoles": "two or three unique lesson roles; the speaker must be included",
    "layout": "approved id from layouts.json",
    "dialogue": "speech bubble and voice text, at most 100 characters",
    "background": "background id approved by the selected world pack",
    "estimatedDurationMs": "2000 to 8000",
    "callout": {
      "label": "optional short label, at most 14 characters",
      "theme": "neutral | question | warm | cool | violet | gold"
    }
  },
  "materializedScene": {
    "speaker": "character asset id resolved from speakerRole",
    "characters": "concrete placements resolved from visibleRoles and layout",
    "voice": "Fish voice resolved from the selected world pack"
  },
  "run": {
    "input": "exact topic and packaged story world",
    "approval": "one approval covering at most three render attempts",
    "provenance": "format, version, plan hash, world pack, layout file, and runner version",
    "audio": "one generated clip per scene plus fixed music",
    "inspection": "technical checks plus agent-reviewed creative checks",
    "output": "final MP4 path"
  }
}