Tests: mean_reversion (a fitted model that buys when the price has fallen unusually far below its recent
    level; default KO), trend_following (a model that rides a trend while it lasts; SPY), momentum (holds
    while the last few months were up; QQQ), buy_the_dip (buys after two days of sharp falls, the 2-day RSI
    under 10; SPY), famous_rule (the 200-day line: hold above the 200-day average, cash below; SPY), and mvo
    (a book of up to 20 stocks of an index picked each quarter by mean-variance optimisation, from the companies
    in the index on that date; it takes `index`, not a ticker, and is set against holding the index's fund).

    Its card draws the circuit as the lab does and lights each card as it runs, with the result under it.
    get_primitives_run_progress follows it by its task_id; when it has finished it answers with the result,
    report_url and offers, each with its exact call, the first one tracking the test live
    (start_paper_trade). The circuit card shows the result, so a ready test needs no show_report_card.

    Every account runs it within a daily allowance; a refused call does not count, and get_started and
    every run's answer give today's count.

    Args:
        test: mean_reversion, trend_following, momentum, buy_the_dip, famous_rule or mvo.
        ticker: Optional. The stock or fund to test it on, as its symbol ('AAPL', 'SPY'); else the test's own.
        index: Optional, for mvo: nasdaq100 (its own) or dow30. The book on the S&P 500 does not run here
            yet (more than a run here does in full in under a minute), and another index (the DAX, the
            FTSE 100) has no dated members: pass what the person asked all the same, and QuanterLab answers
            with its note and the same book on the Nasdaq 100, one tap away, and nothing runs.
        settings: Optional. The one setting a test lets a person change, by name: mean_reversion
            {"z_entry": 1 to 3.5}, trend_following {"trend_threshold": 0.25 to 3}, momentum {"months": 1 to
            4}, buy_the_dip {"rsi_below": 2 to 30}, famous_rule {"days": 20 to 300}, mvo {"holdings": 5 to
            30}, e.g. {"days": 100} for
            the 100-day line; and on every test {"stop_loss": 0.5 to 30}, the lab's Stop Loss card added
            under the forward test, which sells everything once the run has lost that many percent since the
            start of the month. A test changed by talking ("use the 100-day line instead", "add a stop
            loss") is the same call: the same test and stock and the last run's settings with that one change;
            the card draws the changed circuit and runs it. Without settings the test runs as it stands.
        question: Optional. One sentence restating what the run should answer, not the person's message: the
            title of the report, and kept only as that.
        study: Optional, instead of test. A published paper's id (from search or fetch). Unchanged, it answers
            at once with the paper's registered result: the run its last registered window recorded, from that
            window's date to the day it was recorded, and it uses none of today's runs. Changed (its settings)
            or with to_today, it runs the paper's circuit from that window's date to today. It takes no ticker;
            its `settings` are the settings the paper names (fetch lists them, e.g. {"symbol": "QQQ"} for which
            fund, {"spread_bps": 20} for the trading cost), and a refusal names them.
        to_today: Optional, with study. True runs the paper's circuit unchanged from its last registered window
            to today, a run like any other: what the person asks for with "run it up to today", or a tap on
            that offer after a paper's registered result.