Use first: list_boards, create_pin, create_schedule and get_rate_meter
    all need an account_id from here. Also read pinbridge://accounts. To
    connect a new account or fix reconnect_required, the user must use the
    PinBridge dashboard; there is no tool for that.

    Returns {"items": [...], "connect_url": "...", "next_step": ...}. items has
    one entry per account with id (the account_id), username, display_name,
    scopes (comma-separated), token_expires_at and health: health_status
    (healthy, refresh_due, reconnect_required or scope_missing),
    health_message, reconnect_required and missing_scopes. connect_url opens
    the dashboard's connect step. When items is empty nothing is connected:
    next_step says to give the user connect_url. Accounts outside this API
    key's allow-list are omitted. Never fails for a valid key.