Rework Overall At Risk layout

[k2the4]

Reworks the Overall > At Risk view to match the requested layout:

• One long horizontal filter bar with only column, lower/upper bounds, and sort.
• Filter bar sits above the results.
• Filtered Students is the main left-hand table.
• Distribution and Top Students are grouped in a right-hand stack.
• Risk-table sorting now follows the selected column and sort direction.
• Removed the distribution shortcut cards from the filter area.