feat: [notification] 알림설정 soundType API 연동

- getGroupedSettings()에서 soundType 반환 (settings.sound_type)
- updateGroupedSettings()에서 soundType 저장 (settings JSON)
- UpdateGroupedSettingRequest에 soundType 검증 추가 (default/sam_voice/mute)

app/Services/NotificationSettingService.php

@@ -265,15 +265,18 @@ public function getGroupedSettings(): array
 
                 if ($settings->has($type)) {
                     $setting = $settings->get($type);
+                    $soundType = $setting->settings['sound_type'] ?? 'default';
                     $groupData[$camelKey] = [
                         'enabled' => $setting->push_enabled,
                         'email' => $setting->email_enabled,
+                        'soundType' => $soundType,
                     ];
                 } else {
                     // 기본값
                     $groupData[$camelKey] = [
                         'enabled' => false,
                         'email' => false,
+                        'soundType' => 'default',
                     ];
                 }
             }
@@ -330,6 +333,17 @@ public function updateGroupedSettings(array $data): array
 
                     if (isset($groupData[$camelKey])) {
                         $itemData = $groupData[$camelKey];
+
+                        // 기존 settings JSON을 유지하면서 sound_type만 업데이트
+                        $existing = NotificationSetting::where('tenant_id', $tenantId)
+                            ->where('user_id', $userId)
+                            ->where('notification_type', $type)
+                            ->first();
+                        $existingSettings = $existing?->settings ?? [];
+                        if (isset($itemData['soundType'])) {
+                            $existingSettings['sound_type'] = $itemData['soundType'];
+                        }
+
                         NotificationSetting::updateOrCreate(
                             [
                                 'tenant_id' => $tenantId,
@@ -342,6 +356,7 @@ public function updateGroupedSettings(array $data): array
                                 'sms_enabled' => false,
                                 'in_app_enabled' => $itemData['enabled'] ?? false,
                                 'kakao_enabled' => false,
+                                'settings' => $existingSettings ?: null,
                             ]
                         );
                     }