web: migrate health notifications to js_interop; add browser hook

- Replace dart:js with package:js in health_check_service_web.dart\n- Implement showHealthCheckNotification in web/index.html\n- Pin js dependency to ^0.6.7 for flutter_secure_storage_web compatibility

auth: harden AuthInterceptor + tests

- Allow overrideAuthRepository injection for testing\n- Normalize imports to package: paths\n- Add unit test covering token attach, 401→refresh→retry, and failure path\n- Add integration test skeleton gated by env vars

ui/data: map User.companyName to list column

- Add companyName to domain User\n- Map UserDto.company?.name\n- Render companyName in user_list

cleanup: remove legacy equipment table + unused code; minor warnings

- Remove _buildFlexibleTable and unused helpers\n- Remove unused zipcode details and cache retry constant\n- Fix null-aware and non-null assertions\n- Address child-last warnings in administrator dialog

docs: update AGENTS.md session context

lib/services/health_check_service_web.dart

@@ -1,17 +1,19 @@
-import 'dart:js' as js;
-
 import 'package:flutter/foundation.dart';
+import 'package:js/js.dart';
 
-/// 웹 플랫폼을 위한 알림 구현
+// JS interop 선언: window.showHealthCheckNotification(title, message, status)
+@JS('showHealthCheckNotification')
+external void _showHealthCheckNotification(
+  String title,
+  String message,
+  String status,
+);
+
+/// 웹 플랫폼을 위한 알림 구현 (js_interop 기반)
 void showNotification(String title, String message, String status) {
   try {
-    // JavaScript 함수 호출
-    js.context.callMethod('showHealthCheckNotification', [
-      title,
-      message,
-      status,
-    ]);
+    _showHealthCheckNotification(title, message, status);
   } catch (e) {
     debugPrint('웹 알림 표시 실패: $e');
   }
-}
+}