chore: 清理废弃代码和 lint 警告

- 删除旧的 _chip 方法（服药次数改用滚轮后遗留）
- 移除多余的 ! 非空断言

health_app/lib/pages/doctor/doctor_report_detail_page.dart

@@ -306,7 +306,7 @@ class _DoctorReportDetailPageState
             width: double.infinity,
             child: OutlinedButton.icon(
               onPressed: () {
-              pushRoute(ref, 'reportOriginal', params: {'url': fileUrl!, 'title': '原始报告'});
+              pushRoute(ref, 'reportOriginal', params: {'url': fileUrl, 'title': '原始报告'});
             },
               icon: const Icon(Icons.visibility, size: 18),
               label: const Text('查看原始报告'),