feat: 알림음 시스템 - Android 6개 NotificationChannel 추가

- 결제/수주/발주/계약/일반/긴급 채널 추가
- 각 채널별 커스텀 알림음 파일 추가 (wav)

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

android/app/src/main/java/com/codebridgex/webapp/MainActivity.java

@@ -13,8 +13,12 @@ import com.getcapacitor.BridgeActivity;
 public class MainActivity extends BridgeActivity {
 
     // 채널 ID (FCM payload의 android.notification.channel_id 로 사용할 값)
-    public static final String CHANNEL_DEFAULT = "push_default";
-    public static final String CHANNEL_URGENT  = "push_urgent";
+    public static final String CHANNEL_DEFAULT        = "push_default";
+    public static final String CHANNEL_URGENT         = "push_urgent";
+    public static final String CHANNEL_PAYMENT        = "push_payment";
+    public static final String CHANNEL_SALES_ORDER    = "push_sales_order";
+    public static final String CHANNEL_PURCHASE_ORDER = "push_purchase_order";
+    public static final String CHANNEL_CONTRACT       = "push_contract";
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -28,40 +32,88 @@ public class MainActivity extends BridgeActivity {
         NotificationManager nm = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
         if (nm == null) return;
 
-        // 이미 존재하면 생성 안 함 (중복 방지)
+        // 이미 모든 채널이 존재하면 생성 안 함 (중복 방지)
         if (nm.getNotificationChannel(CHANNEL_DEFAULT) != null
-                && nm.getNotificationChannel(CHANNEL_URGENT) != null) {
+                && nm.getNotificationChannel(CHANNEL_URGENT) != null
+                && nm.getNotificationChannel(CHANNEL_PAYMENT) != null
+                && nm.getNotificationChannel(CHANNEL_SALES_ORDER) != null
+                && nm.getNotificationChannel(CHANNEL_PURCHASE_ORDER) != null
+                && nm.getNotificationChannel(CHANNEL_CONTRACT) != null) {
             return;
         }
 
         // raw 리소스 사운드 (android/app/src/main/res/raw/ 에 넣어야 함)
-        Uri soundDefault = Uri.parse("android.resource://" + getPackageName() + "/raw/push_default");
-        Uri soundUrgent  = Uri.parse("android.resource://" + getPackageName() + "/raw/push_urgent");
+        Uri soundDefault       = Uri.parse("android.resource://" + getPackageName() + "/raw/push_default");
+        Uri soundUrgent        = Uri.parse("android.resource://" + getPackageName() + "/raw/push_urgent");
+        Uri soundPayment       = Uri.parse("android.resource://" + getPackageName() + "/raw/push_payment");
+        Uri soundSalesOrder    = Uri.parse("android.resource://" + getPackageName() + "/raw/push_sales_order");
+        Uri soundPurchaseOrder = Uri.parse("android.resource://" + getPackageName() + "/raw/push_purchase_order");
+        Uri soundContract      = Uri.parse("android.resource://" + getPackageName() + "/raw/push_contract");
 
         AudioAttributes aa = new AudioAttributes.Builder()
                 .setUsage(AudioAttributes.USAGE_NOTIFICATION)
                 .setContentType(AudioAttributes.CONTENT_TYPE_SONIFICATION)
                 .build();
 
-        // 1) 기본 채널
+        // 1) 기본 채널 (일반 알림)
         NotificationChannel chDefault = new NotificationChannel(
                 CHANNEL_DEFAULT,
-                "Default Notifications",
+                "일반 알림",
                 NotificationManager.IMPORTANCE_DEFAULT
         );
-        chDefault.setDescription("General notifications");
+        chDefault.setDescription("일반 알림");
         chDefault.setSound(soundDefault, aa);
 
-        // 2) 긴급 채널
+        // 2) 긴급 채널 (신규업체 등록)
         NotificationChannel chUrgent = new NotificationChannel(
                 CHANNEL_URGENT,
-                "Urgent Notifications",
+                "신규업체 등록",
                 NotificationManager.IMPORTANCE_HIGH
         );
-        chUrgent.setDescription("Urgent notifications");
+        chUrgent.setDescription("신규업체 등록 알림");
         chUrgent.setSound(soundUrgent, aa);
 
+        // 3) 결제 채널
+        NotificationChannel chPayment = new NotificationChannel(
+                CHANNEL_PAYMENT,
+                "결제 알림",
+                NotificationManager.IMPORTANCE_HIGH
+        );
+        chPayment.setDescription("결제 관련 알림");
+        chPayment.setSound(soundPayment, aa);
+
+        // 4) 수주 채널
+        NotificationChannel chSalesOrder = new NotificationChannel(
+                CHANNEL_SALES_ORDER,
+                "수주 알림",
+                NotificationManager.IMPORTANCE_DEFAULT
+        );
+        chSalesOrder.setDescription("수주 관련 알림");
+        chSalesOrder.setSound(soundSalesOrder, aa);
+
+        // 5) 발주 채널
+        NotificationChannel chPurchaseOrder = new NotificationChannel(
+                CHANNEL_PURCHASE_ORDER,
+                "발주 알림",
+                NotificationManager.IMPORTANCE_DEFAULT
+        );
+        chPurchaseOrder.setDescription("발주 관련 알림");
+        chPurchaseOrder.setSound(soundPurchaseOrder, aa);
+
+        // 6) 계약 채널
+        NotificationChannel chContract = new NotificationChannel(
+                CHANNEL_CONTRACT,
+                "계약 알림",
+                NotificationManager.IMPORTANCE_DEFAULT
+        );
+        chContract.setDescription("계약 관련 알림");
+        chContract.setSound(soundContract, aa);
+
         nm.createNotificationChannel(chDefault);
         nm.createNotificationChannel(chUrgent);
+        nm.createNotificationChannel(chPayment);
+        nm.createNotificationChannel(chSalesOrder);
+        nm.createNotificationChannel(chPurchaseOrder);
+        nm.createNotificationChannel(chContract);
     }
 }