{
    "title": "agent_availability",
    "type": "object",
    "properties": {
        "id": {
            "type": "integer",
            "description": "Primary key, auto-increment"
        },
        "seat_id": {
            "type": "integer",
            "description": "FK to support_seats.id"
        },
        "status": {
            "type": "string",
            "description": "online|busy|away|offline"
        },
        "last_heartbeat_at": {
            "type": "string",
            "format": "date-time",
            "description": "Last heartbeat timestamp"
        }
    },
    "required": [
        "id",
        "seat_id",
        "status"
    ]
}