Subtotals for Grouped Categories

​As a user, I want the system to calculate and display a subtotal for each category when data grouping is applied.

This will allow for a quicker financial/data analysis without having to manually compute the sums for each group.

Proposed Behavior

• When rows are grouped by a specific category (e.g., Expense Type, Month, Project), a dedicated Subtotal Row should appear at the bottom (or top) of each collapsed/expanded group.

• The subtotal must dynamically update based on the active filters applied to the view.