Archived sessions fold back into every figure the page derives off the
session list: rowsOfSnapshot now tags archived rows instead of dropping
them, and one coveredRowsOf pass scopes the KPI band, charts, heatmap,
skills, and the session grid together. A "Filter sessions" select next to
the list's search box offers dsh's own archived-filter set — All (show
archived) by default, Hide archived, Archived only. The Active Sessions
card follows the picked coverage (Sessions incl. the window's archived
count under All; Active/Archived Sessions over the full-list total under
the narrow scopes), archived cards wear an Archived tag and refuse to
open like dsh does, and kpisOf drops its now-unused listed param.