feat(ui): add reduced-motion floor and tasteful hover micro-interactions

Global @media (prefers-reduced-motion: reduce) rule in MuiCssBaseline
collapses every animation/transition duration to near-zero at once --
covers MUI's own Dialog/Menu/Collapse/ripple transitions and every
hover-lift added below, so accessibility doesn't need re-checking
per-component as more motion gets added later.

Dashboard stat tiles and Kanban cards get a subtle hover lift (shadow
deepens, translateY(-2px)/-1px), matching the hover pattern the
landing page's feature cards already had -- these are the two places
a small lift reads as an affordance rather than noise: stat tiles are
dashboard-customization-adjacent, and kanban cards are literally
draggable, so the lift reinforces the existing grab-cursor signal
instead of competing with it. Left everything else alone -- most
cards on this app hold passive content, not something to invite a
hover response.

job-tracker-ui/src/components/KanbanBoard.tsx

@@ -199,6 +199,9 @@ export default function KanbanBoard() {
                           cursor: "grab",
                           borderRadius: 2.5,
                           borderLeft: `4px solid ${c}`,
+                          transition: "box-shadow .15s, transform .15s",
+                          "&:hover": { boxShadow: 4, transform: "translateY(-1px)" },
+                          "&:active": { cursor: "grabbing" },
                         }}
                       >
                         <CardContent sx={{ p: 1.25, "&:last-child": { pb: 1.25 } }}>