UseTableGroupedRows

Hook that groups a flat data array into collapsible section rows. Each distinct groupBy value becomes a full-width section-header row with a chevron toggle, the group label, and a member count; collapsing hides that group's data rows while keeping the header visible. The disclosure state lives on the chevron button, not the native table row. Mirrors useTableTreeState: the consumer owns the collapsedGroups set and the hook returns {data, plugin, idKey}: pass them to Table as data, plugins, and idKey respectively. Grouping runs on the rows you hand it, so with pagination the order is filter, sort, slice, then group: sort by the group key first and the user's keys second, so a section's rows stay contiguous and each page appends to the bottom of the table instead of splicing rows in above the reader. A page that ends on a row count still cuts mid-section, and the heading then counts what has loaded rather than what exists: "6" quietly becoming "10". Where the full result set is in hand, carry the cut forward to the end of the section it lands in: every rendered section is then whole and its count is a total.