Fix RFM date range consistency

src/components/Layout.tsx

@@ -3,6 +3,7 @@ import { Outlet, Link, useLocation } from 'react-router-dom';
 import { LayoutDashboard, Users, BarChart3, ChevronLeft, ChevronRight, Package, Loader2, LogOut, Megaphone, Grid3X3 } from 'lucide-react';
 import type { DateRange, OrderData, StockData } from '../types';
 import { fetchData, fetchStock, logout } from '../dataService';
+import { rangeForLastDays } from '../dateRanges';
 
 const Layout = () => {
   const location = useLocation();
@@ -20,10 +21,7 @@ const Layout = () => {
         return { start: new Date(parsed.start), end: new Date(parsed.end) };
       } catch (e) { console.error(e); }
     }
-    const end = new Date();
-    const start = new Date();
-    start.setMonth(start.getMonth() - 1);
-    return { start, end };
+    return rangeForLastDays(30);
   });
 
   const [ordersData, setOrdersData] = useState<OrderData[]>([]);