Save Dashboard

    If a dashboard with this name already exists it is updated; otherwise a
    new one is created.

    Size each panel with a named ``size`` from the catalog below (PREFERRED
    — guarantees a legible layout) and omit positions entirely: panels are
    auto-placed in the order given (left-to-right, top-to-bottom on a
    12-column grid, wrapping rows, never overlapping).

    Size catalog and when to use each:

    - ``small-square`` (3x6): single ``stat`` metrics.
    - ``half-rectangle`` (6x6): ``line``/``bar``/``area`` trends, two per row.
    - ``half-square`` (6x9): ``radar``, ``composed``, denser charts.
    - ``full-rectangle`` (12x9): wide time-series comparisons.
    - ``full-square`` (12x12): ``table`` panels.

    Args:
        name: Dashboard name — the upsert key.
        panels: Optional list of panel definitions. Each panel is an object:

            - ``title`` (str, required): panel heading.
            - ``chart_type`` (str, required): one of ``line``, ``bar``,
              ``composed``, ``area``, ``radar``, ``stat``, ``table``.
            - ``query`` (object, required): what to chart —
              ``{"cube": "check_trend", "measures": [...],
              "dimensions": [...], "filters": [...],
              "time_dimensions": [...], "order": {...}}``. ``measures`` is
              required; everything else is optional. ``cube`` defaults to
              ``check_trend``. The dashboard ``time_range`` applies to all
              panels — panels do NOT carry their own time range.
            - ``size`` (str): a catalog name (see above). Required unless
              ``layout`` is given; wins over ``layout`` w/h if both appear.
            - ``layout`` (object): raw grid placement
              ``{"x": >=0, "y": >=0, "w": >=1, "h": >=1}`` (integers).
              Only needed when not using ``size``, or to pin an explicit
              position (give both ``x`` and ``y``; with ``size``, w/h are
              ignored). Heights below the legibility floor are sized up on
              save: ``h >= 6`` when ``w <= 6``, ``h >= 9`` when ``w > 6``.
            - ``table_config`` (object, optional): ONLY for
              ``chart_type == "table"``.

            ``check_trend`` measures: ``avg_check_value``, ``issue_rate``,
            ``error_rate``, ``datapoint_count``, ``issue_count``,
            ``error_count``, ``test_run_count``, ``avg_latency``,
            ``sum_cost``, ``input_token_count``, ``output_token_count``.
            ``check_trend`` dimensions: ``check.name``, ``check.id``,
            ``target.name``, ``target.id``, ``scenario.name``,
            ``scenario.id``, ``test_run.id``, ``test_run.type``,
            ``test_run.is_latest_for_target``, ``source``, ``provider``,
            ``request_model_name``, ``response_model_name``, ``tag``.
            Use ``query_analytics(include_metadata=True)`` for the
            authoritative, current set.

            Example panel::

                {"title": "Avg Check Value by Check", "chart_type": "bar",
                 "query": {"measures": ["avg_check_value"],
                           "dimensions": ["check.name"]},
                 "size": "half-rectangle"}
        description: Optional dashboard description.
        time_range: Optional default look-back window for the whole
            dashboard. One of: LAST_HOUR, LAST_24_HOURS, LAST_7_DAYS,
            LAST_14_DAYS, LAST_30_DAYS, LAST_90_DAYS. Defaults to
            LAST_90_DAYS when omitted.

    Returns:
        JSON with the saved dashboard and ``action`` (created/updated).
        When sizing or dimensions were changed on save (size overriding
        layout w/h, or a height floored), an ``adjustments`` list reports
        each change: ``{"panel", "field", "from", "to", "reason"}``.