id, prompt,
choices[], and optional effects (score, flags, inventory, time, detection
risk).
{
"id": "start",
"prompt": "You receive an email claiming to be from IT...",
"choices": [
{"label": "Click the link", "to": "phished", "effects": {"risk": "+=20"}},
{"label": "Report to security", "to": "good_call", "effects": {"risk": "-=5", "badge": "reporter"}}
]
}