feat: 新增商品 Excel 匯入功能與修復 HTTPS 混合內容問題

1. 新增商品 Excel 匯入功能 (ProductImport, Export Template)
2. 調整商品代號驗證規則為 1-5 碼 (Controller & Import)
3. 修正 HTTPS Mixed Content 問題 (AppServiceProvider)

package.json

@@ -21,6 +21,7 @@
     },
     "dependencies": {
         "@inertiajs/react": "^2.3.4",
+        "@radix-ui/react-accordion": "^1.2.12",
         "@radix-ui/react-alert-dialog": "^1.1.15",
         "@radix-ui/react-checkbox": "^1.3.3",
         "@radix-ui/react-collapsible": "^1.1.12",