Clarify the frequency and horizon of maximum drawdown statistics

[Yuning598]

Background

The explorer currently displays max drawdown without stating that it is calculated from a cumulative wealth path built from monthly returns. The requested output should make the observation frequency and evaluation horizon unambiguous.

Decision required

Determine whether the requested monthly/yearly distinction means:

1. maximum drawdown calculated from monthly observations over the selected full sample; or
2. separate drawdown summaries for monthly-sampled and calendar-year return series.

Acceptance criteria

• The adopted monthly/yearly interpretation is documented before implementation.
• Every displayed drawdown value states its observation frequency and sample horizon.
• The methodology explains the wealth-path and peak-to-trough formula.
• Python and browser-side calculations agree for the selected date window.
• Tests cover monotonic gains, a single drawdown, recovery, and incomplete years.