fix: 修正重複註冊防呆邏輯

lib/RegisterPage.dart

@@ -176,13 +176,13 @@ class _RegisterPageState extends State<RegisterPage> {
       String password = _passwordController.text;
 
       var result = await conn.execute(
-        'SELECT * FROM HomeLogin WHERE homeEmail = :email',
-        {'email': email},
+        'SELECT * FROM HomeLogin WHERE homeEmail = :email OR homeName = :name',
+        {'email': email, 'name': name},
       );
 
       if (result.rows.isNotEmpty) {
         ScaffoldMessenger.of(context).showSnackBar(
-          SnackBar(content: Text('註冊失敗：電子信箱已被使用，請嘗試更換電子信箱')),
+          SnackBar(content: Text('註冊失敗：電子信箱或帳號名稱已被使用，請嘗試更換或登入')),
         );
       } else {
         // TODO: Phone Address is setting not null in database, remove it or setting default value