fix: 移除筛选遮罩层防止阻塞Tab切换、部门选择按编号排序

- 删除三个筛选面板的fixed backdrop div，不再阻塞页面交互
- 部门下拉选项按编号排序（业务一部→二部→三部→五部→六部）

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/App.tsx

@@ -427,7 +427,11 @@ export default function App() {
     return mc && mb && md && mm && mr;
   }), [customerData, customerFilters]);
   const uniqueBrands = useMemo(() => Array.from(new Set(customerData.map((s) => s.brand).filter(Boolean))), [customerData]);
-  const uniqueDepts = useMemo(() => Array.from(new Set(customerData.map((s) => s.department).filter(Boolean))), [customerData]);
+  const uniqueDepts = useMemo(() => {
+    const numMap: Record<string, number> = { '一': 1, '二': 2, '三': 3, '四': 4, '五': 5, '六': 6, '七': 7, '八': 8, '九': 9, '十': 10 };
+    const getOrder = (name: string) => { const m = name.match(/[一二三四五六七八九十]/); return m ? (numMap[m[0]] || 99) : 99; };
+    return Array.from(new Set(customerData.map((s) => s.department).filter(Boolean))).sort((a, b) => getOrder(a) - getOrder(b));
+  }, [customerData]);
   const uniqueRegions = useMemo(() => Array.from(new Set(customerData.map((s) => s.region))), [customerData]);
   const uniqueCities = useMemo(() => Array.from(new Set(customerData.map((s) => s.city).filter(Boolean))), [customerData]);
   const uniqueCustomerNames = useMemo(() => Array.from(new Set(customerData.map((s) => s.customer).filter(Boolean))), [customerData]);
@@ -1044,7 +1048,6 @@ export default function App() {
                 <AnimatePresence>
                   {isInventoryFilterOpen && (
                     <>
-                      <div className="fixed inset-0 z-40" />
                       <motion.div
                         initial={{ opacity: 0, y: 10, scale: 0.95 }}
                         animate={{ opacity: 1, y: 0, scale: 1 }}