feat: 포그라운드 푸시 알림 소리 추가

- Capacitor 패키지 추가 (@capacitor/core, @capacitor/push-notifications)
- 포그라운드에서 푸시 수신 시 알림 소리 재생
- 알림 소리 파일 추가 (push_notification.wav)

package-lock.json

@@ -5,6 +5,8 @@
     "packages": {
         "": {
             "dependencies": {
+                "@capacitor/core": "^8.0.0",
+                "@capacitor/push-notifications": "^8.0.0",
                 "htmx.org": "^2.0.8"
             },
             "devDependencies": {
@@ -32,6 +34,24 @@
                 "url": "https://github.com/sponsors/sindresorhus"
             }
         },
+        "node_modules/@capacitor/core": {
+            "version": "8.0.0",
+            "resolved": "https://registry.npmjs.org/@capacitor/core/-/core-8.0.0.tgz",
+            "integrity": "sha512-250HTVd/W/KdMygoqaedisvNbHbpbQTN2Hy/8ZYGm1nAqE0Fx7sGss4l0nDg33STxEdDhtVRoL2fIaaiukKseA==",
+            "license": "MIT",
+            "dependencies": {
+                "tslib": "^2.1.0"
+            }
+        },
+        "node_modules/@capacitor/push-notifications": {
+            "version": "8.0.0",
+            "resolved": "https://registry.npmjs.org/@capacitor/push-notifications/-/push-notifications-8.0.0.tgz",
+            "integrity": "sha512-xJWQLqAfC8b2ETqAPmwDnkKB4t/lVrbYc2D8VpA2fSu10JFSL/R722Vk0Lfl9Lo9WusmyIiQbVfILNQ3iFNGKw==",
+            "license": "MIT",
+            "peerDependencies": {
+                "@capacitor/core": ">=8.0.0"
+            }
+        },
         "node_modules/@esbuild/aix-ppc64": {
             "version": "0.25.12",
             "resolved": "https://registry.npmjs.org/@esbuild/aix-ppc64/-/aix-ppc64-0.25.12.tgz",
@@ -2607,7 +2627,6 @@
             "version": "2.8.1",
             "resolved": "https://registry.npmjs.org/tslib/-/tslib-2.8.1.tgz",
             "integrity": "sha512-oJFu94HQb+KVduSUQL7wnpmqnfmLsOA/nAh6b6EH0wCEoK0/mPeXU6c3wKDV83MkOuHPRHtSXKKU99IBazS/2w==",
-            "dev": true,
             "license": "0BSD"
         },
         "node_modules/update-browserslist-db": {