feat: add Classification column and Excel-style column filters to Pricing & Units tab

- Added Classification column next to Line with color-coded badges (Core=blue, OOC=amber)
- Added Excel-style filter icons on Article Name (text search), Line, and Classification headers
- Filter icons appear on hover; turn blue when active
- Multi-select popover for Line and Classification; free-text popover for Article Name
- Filters work additively alongside the existing global search bar
- ArticleDetails: removed Tariff/Barcode/Origin columns and tab to simplify the view

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/ArticleDetails.tsx

@@ -8,7 +8,7 @@ interface ArticleDetailsProps {
   onEdit: (index: number) => void;
 }
 
-type TabType = 'all' | 'missingDetailsDE' | 'missingDetailsEN' | 'missingAnyDetails' | 'lowStock' | 'missingTariff';
+type TabType = 'all' | 'missingDetailsDE' | 'missingDetailsEN' | 'missingAnyDetails' | 'lowStock';
 
 export function ArticleDetails({ data, onEdit }: ArticleDetailsProps) {
   const [activeTab, setActiveTab] = useState<TabType>('all');
@@ -29,15 +29,13 @@ export function ArticleDetails({ data, onEdit }: ArticleDetailsProps) {
     if (activeTab === 'missingDetailsEN') result = result.filter(r => !r.row[COLUMNS.DETAILS_EN]);
     if (activeTab === 'missingAnyDetails') result = result.filter(r => !r.row[COLUMNS.DETAILS_DE] || !r.row[COLUMNS.DETAILS_EN]);
     if (activeTab === 'lowStock') result = result.filter(r => Number(r.row[COLUMNS.ITEM_AVAILABLE] || 0) <= 0);
-    if (activeTab === 'missingTariff') result = result.filter(r => !r.row[COLUMNS.TARIFF_CODE]);
 
     // Search filter
     if (search) {
       const s = search.toLowerCase();
       result = result.filter(r => 
         String(r.row[COLUMNS.ARTICLE_NO] || '').toLowerCase().includes(s) ||
-        String(r.row[COLUMNS.ARTICLE_NAME] || '').toLowerCase().includes(s) ||
-        String(r.row[COLUMNS.BARCODE] || '').toLowerCase().includes(s)
+        String(r.row[COLUMNS.ARTICLE_NAME] || '').toLowerCase().includes(s)
       );
     }
 
@@ -98,7 +96,6 @@ export function ArticleDetails({ data, onEdit }: ArticleDetailsProps) {
     { id: 'missingDetailsEN', label: 'No Details EN' },
     { id: 'missingAnyDetails', label: 'Missing Details' },
     { id: 'lowStock', label: 'Out of Stock' },
-    { id: 'missingTariff', label: 'No Tariff Code' },
   ];
 
   return (
@@ -125,7 +122,7 @@ export function ArticleDetails({ data, onEdit }: ArticleDetailsProps) {
           <Search className="absolute left-3 top-1/2 -translate-y-1/2 w-4 h-4 text-slate-500" />
           <input
             type="text"
-            placeholder="Search SKU, Name, Barcode..."
+            placeholder="Search SKU or Name..."
             value={search}
             onChange={e => { setSearch(e.target.value); setPage(1); }}
             className="w-full pl-9 pr-4 py-2 bg-slate-900/50 border border-slate-700 rounded-md text-sm text-white focus:outline-none focus:border-indigo-500 focus:ring-1 focus:ring-indigo-500"
@@ -149,9 +146,6 @@ export function ArticleDetails({ data, onEdit }: ArticleDetailsProps) {
                 {[
                   { col: COLUMNS.ARTICLE_NO, label: 'SKU' },
                   { col: COLUMNS.ARTICLE_NAME, label: 'Name' },
-                  { col: COLUMNS.BARCODE, label: 'Barcode' },
-                  { col: COLUMNS.TARIFF_CODE, label: 'Tariff' },
-                  { col: COLUMNS.COUNTRY_ORIGIN, label: 'Origin' },
                   { col: COLUMNS.CLASSIFICATION, label: 'Class' },
                   { col: COLUMNS.ITEM_AVAILABLE, label: 'Stock' },
                   { col: COLUMNS.DETAILS_DE, label: 'Details DE' },
@@ -180,9 +174,6 @@ export function ArticleDetails({ data, onEdit }: ArticleDetailsProps) {
                   <td className="px-3 py-2 font-medium text-slate-200 max-w-[150px] truncate" title={row[COLUMNS.ARTICLE_NAME]}>
                     {row[COLUMNS.ARTICLE_NAME]}
                   </td>
-                  <td className="px-3 py-2 text-slate-400">{row[COLUMNS.BARCODE] || '—'}</td>
-                  <td className="px-3 py-2 text-slate-400">{row[COLUMNS.TARIFF_CODE] || '—'}</td>
-                  <td className="px-3 py-2 text-slate-400">{row[COLUMNS.COUNTRY_ORIGIN] || '—'}</td>
                   <td className="px-3 py-2">
                     <span className={cn(
                         "px-1.5 py-0.5 rounded-[4px] text-[10px] font-bold border",
@@ -221,7 +212,7 @@ export function ArticleDetails({ data, onEdit }: ArticleDetailsProps) {
               ))}
               {paginatedData.length === 0 && (
                 <tr>
-                  <td colSpan={10} className="px-4 py-8 text-center text-slate-500">
+                  <td colSpan={7} className="px-4 py-8 text-center text-slate-500">
                     No articles found.
                   </td>
                 </tr>