fix(sms-permission): re-request on denial and guide permanent denial to app settings

Summary: Improve SMS permission UX so users can request again after denial and are guided to app settings when permanently denied.\nChanges: handle Permission.sms status in controllers, show settings dialog for permanently denied, use kIsWeb guard, context-safety across async.\nValidation: scripts/check.sh passed (analyze/tests OK).\nRisk & Rollback: low; scoped to permission request flow. Revert two controllers if issues.

lib/controllers/sms_scan_controller.dart

@@ -5,6 +5,8 @@ import '../services/sms_scan/subscription_converter.dart';
 import '../services/sms_scan/subscription_filter.dart';
 import '../providers/subscription_provider.dart';
 import 'package:provider/provider.dart';
+import 'package:flutter/foundation.dart' show kIsWeb;
+import 'package:permission_handler/permission_handler.dart' as permission;
 import '../utils/logger.dart';
 import '../providers/navigation_provider.dart';
 import '../providers/category_provider.dart';
@@ -57,6 +59,33 @@ class SmsScanController extends ChangeNotifier {
     notifyListeners();
 
     try {
+      // Android에서 SMS 권한 확인 및 요청
+      final ctx = context;
+      if (!kIsWeb) {
+        final smsStatus = await permission.Permission.sms.status;
+        if (!smsStatus.isGranted) {
+          if (smsStatus.isPermanentlyDenied) {
+            // 설정 유도 다이얼로그 표시
+            if (!ctx.mounted) return;
+            await _showPermissionSettingsDialog(ctx);
+            _isLoading = false;
+            notifyListeners();
+            return;
+          }
+
+          final req = await permission.Permission.sms.request();
+          if (!ctx.mounted) return;
+          if (!req.isGranted) {
+            // 거부됨: 안내 후 종료
+            if (!ctx.mounted) return;
+            _errorMessage = AppLocalizations.of(ctx).smsPermissionRequired;
+            _isLoading = false;
+            notifyListeners();
+            return;
+          }
+        }
+      }
+
       // SMS 스캔 실행
       Log.i('SMS 스캔 시작');
       final scannedSubscriptionModels =
@@ -139,6 +168,30 @@ class SmsScanController extends ChangeNotifier {
     }
   }
 
+  Future<void> _showPermissionSettingsDialog(BuildContext context) async {
+    final loc = AppLocalizations.of(context);
+    await showDialog(
+      context: context,
+      builder: (_) => AlertDialog(
+        title: Text(loc.smsPermissionRequired),
+        content: Text(loc.permanentlyDeniedMessage),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.of(context).pop(),
+            child: Text(loc.cancel),
+          ),
+          TextButton(
+            onPressed: () async {
+              await permission.openAppSettings();
+              if (context.mounted) Navigator.of(context).pop();
+            },
+            child: Text(loc.openSettings),
+          ),
+        ],
+      ),
+    );
+  }
+
   Future<void> addCurrentSubscription(BuildContext context) async {
     if (_currentIndex >= _scannedSubscriptions.length) return;