List workspace investigations (canvas data excluded)

Example response

{
  "items": [
    {
      "id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
      "workspace_id": "workspace-123",
      "title": "Peel chain from Binance hot wallet",
      "subject_address": "0xabc...",
      "subject_network": "eth",
      "subject_tx_hash": "0xdef...",
      "status": "open",
      "created_by": "analyst@range.org",
      "created_at": "2026-07-09T00:00:00.000Z",
      "updated_at": "2026-07-09T00:00:00.000Z"
    }
  ],
  "total": 12
}