fix: Android APK 다운로드 window.open, CI npm ci 보강

@capacitor/browser 제거하고 네이티브 WebView에서 window.open 사용.
app node_modules 누락 시 root npm ci 실행.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/package.json

@@ -14,7 +14,6 @@
   "dependencies": {
     "@capacitor/android": "^7.0.0",
     "@capacitor/app": "^7.0.0",
-    "@capacitor/browser": "^7.0.5",
     "@capacitor/core": "^7.0.0",
     "@capacitor/haptics": "^7.0.0",
     "@capacitor/ios": "^7.0.0",

app/src/services/appUpdate.ts

@@ -2,7 +2,6 @@
  * Android 앱 내 업데이트 — /api/mobile-app/info 버전 비교 후 APK 다운로드
  */
 import { App } from '@capacitor/app';
-import { Browser } from '@capacitor/browser';
 import { Capacitor } from '@capacitor/core';
 import {
   isRemoteVersionNewer,
@@ -50,12 +49,8 @@ export async function openApkDownload(release?: MobileAppReleaseInfoDto | null):
   if (!url) return false;
 
   if (Capacitor.isNativePlatform() && Capacitor.getPlatform() === 'android') {
-    try {
-      await Browser.open({ url });
-      return true;
-    } catch {
-      /* fallback */
-    }
+    const opened = window.open(url, '_blank', 'noopener,noreferrer');
+    if (opened) return true;
   }
 
   const a = document.createElement('a');