curl https://api.getspine.ai/v1/canvas/<canvas_id>/tasks \
  -H "X-API-KEY: sk_spine_..."

{
  "success": true,
  "data": {
    "canvas_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "completed": [
      {
        "task_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
        "name": "<string>",
        "task_type": "parent-task",
        "status": "completed",
        "children": "<array>"
      }
    ],
    "not_completed": [
      {
        "task_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
        "name": "<string>",
        "task_type": "parent-task",
        "status": "completed",
        "children": "<array>"
      }
    ]
  }
}

{
  "success": false,
  "error": "X-API-KEY header required"
}

{
  "success": false,
  "error": "Run not found: 550e8400-e29b-41d4-a716-446655440000"
}