feat(ui): unified motion language and interaction states

- Shared transition constants (view/modal/toast/tile) with standard ease-out
- MotionConfig reducedMotion=user plus CSS reduced-motion neutralizer
- Consistent hover/press/focus-visible states across all interactive classes

src/components/ImportPreviewModal.tsx

@@ -1,6 +1,7 @@
 import { motion } from "framer-motion";
 import { FileSpreadsheet, Loader2, X } from "lucide-react";
 import { humanDateTime } from "../lib/metrics";
+import { MODAL_TRANSITION } from "../lib/motion";
 import { MiniMetric } from "./MetricTiles";
 import { Modal } from "./Modal";
 import type { ImportPreview, ImportPreviewRow } from "../types";
@@ -30,6 +31,7 @@ export function ImportPreviewModal({
           initial={{ opacity: 0, y: 18, scale: 0.98 }}
           animate={{ opacity: 1, y: 0, scale: 1 }}
           exit={{ opacity: 0, y: 14, scale: 0.98 }}
+          transition={MODAL_TRANSITION}
         >
           <div className="mb-5 flex items-start justify-between gap-4">
             <div>