UI: Implement Maximize mode for tables. Added a 'MAXIMIZE' button to TopBar and an 'X' close button in fullscreen mode. Hides sidebar and header to provide maximum screen space for data tables.

src/components/ProductDescriptions.tsx

@@ -1,7 +1,7 @@
 import React, { useState, useMemo } from 'react';
 import { ExcelRow } from '../types';
 import { useColumns } from '../contexts/ColumnsContext';
-import { Search, Filter, Edit2, ChevronDown, ChevronUp, X } from 'lucide-react';
+import { Search, Filter, Edit2, ChevronDown, ChevronUp, X, Maximize2 } from 'lucide-react';
 import { cn } from '../lib/utils';
 import { ColumnFilterPopover } from './ColumnFilterPopover';
 
@@ -15,6 +15,7 @@ interface ProductDescriptionsProps {
 
 export function ProductDescriptions({ data, headers, asinColumnIndex, onEdit, rowStatuses }: ProductDescriptionsProps) {
   const COLUMNS = useColumns();
+  const [isFullscreen, setIsFullscreen] = useState(false);
 
   // Description columns that should only have Present/Missing filters
   const DESCRIPTION_COLUMNS = [COLUMNS.LONG_DE, COLUMNS.LONG_EN, COLUMNS.SHORT_DE, COLUMNS.SHORT_EN, COLUMNS.DETAILS_DE, COLUMNS.DETAILS_EN];