refactor: 重命名 QRScanner 函数，统一调用方式

src/composables/useQRScanner.ts

@@ -18,17 +18,17 @@ export function useQRScanner() {
   const { vibrate } = useHaptics();
   const isSupported = Capacitor.isNativePlatform();
 
-  const showError = async (message: string) => {
+  async function showError(message: string) {
     const toast = await toastController.create({
       message,
       duration: 2000,
-      position: "top",
+      position: "bottom",
       color: "danger",
     });
     await toast.present();
   };
 
-  const openScanner = async (options?: ScannerOptions): Promise<QRScanResult | null> => {
+  async function open(options?: ScannerOptions): Promise<QRScanResult | null> {
     try {
       if (!isSupported) {
         await showError(t("scanner.notSupported"));
@@ -62,10 +62,10 @@ export function useQRScanner() {
       }
       return null;
     }
-  };
+  }
 
   return {
     isSupported,
-    openScanner,
+    open,
   };
 }