Create Instance
Create a new camp/session instance.
Status: upcoming, active, completed, archived (default: upcoming)
Example Request
curl -X POST https://api.checkpoint.b-digital.uk/api/v1/instances \
-H "X-API-Key: YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"name": "Summer Camp 2025",
"description": "Annual summer camp",
"status": "upcoming",
"start_date": "2025-07-01",
"end_date": "2025-07-15"
}'