feat: 修正庫存與撥補單邏輯並整合文件

1. 修復倉庫統計數據加總與樣式。
2. 修正可用庫存計算邏輯（排除不可銷售倉庫）。
3. 撥補單商品列表加入批號與效期顯示。
4. 修正撥補單儲存邏輯以支援精確批號轉移。
5. 整合 FEATURES.md 至 README.md。

resources/js/Pages/Product/Index.tsx

@@ -20,22 +20,22 @@ export interface Category {
 }
 
 export interface Product {
-  id: number;
+  id: string;
   code: string;
   name: string;
-  category_id: number;
+  categoryId: number;
   category?: Category;
   brand?: string;
   specification?: string;
-  base_unit_id: number;
-  base_unit?: Unit;
-  large_unit_id?: number;
-  large_unit?: Unit;
-  conversion_rate?: number;
-  purchase_unit_id?: number;
-  purchase_unit?: Unit;
-  created_at: string;
-  updated_at: string;
+  baseUnitId: number;
+  baseUnit?: Unit;
+  largeUnitId?: number;
+  largeUnit?: Unit;
+  conversionRate?: number;
+  purchaseUnitId?: number;
+  purchaseUnit?: Unit;
+  createdAt?: string;
+  updatedAt?: string;
 }
 
 interface PageProps {
@@ -163,7 +163,7 @@ export default function ProductManagement({ products, categories, units, filters
     setIsDialogOpen(true);
   };
 
-  const handleDeleteProduct = (id: number) => {
+  const handleDeleteProduct = (id: string) => {
     router.delete(route('products.destroy', id), {
       onSuccess: () => {
         // Toast handled by flash message