ci: fail fast when Unity iOS export has no Podfile

EDM4U + com.onesignal.unity.ios/Editor/OneSignaliOSDependencies.xml always
generate a Podfile during iOS export because OneSignalXCFramework is
consumed via CocoaPods. The previous fallback that silently skipped pod
install on a missing Podfile would mask EDM4U / post-processor failures
and ship an IPA without OneSignal native deps. Surface it as an
::error:: instead. Addresses Sherwin's review comment on #870.

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

Author: fadi-george

.github/workflows/e2e.yml

@@ -136,13 +136,18 @@ jobs:
           cacheUnityInstallationOnMac: true
 
       - name: Pod install
+        # EDM4U + com.onesignal.unity.ios/Editor/OneSignaliOSDependencies.xml
+        # always generate a Podfile at iOS export time (OneSignalXCFramework is
+        # consumed via CocoaPods). Missing Podfile means EDM4U or the SDK
+        # post-processor silently failed; fail fast rather than ship an IPA
+        # without OneSignal native deps.
         working-directory: examples/demo/Build/iOS
         run: |
-          if [ -f Podfile ]; then
-            pod install --repo-update
-          else
-            echo "No Podfile in Unity-exported Xcode project; skipping pod install"
+          if [ ! -f Podfile ]; then
+            echo "::error::No Podfile in Unity-exported Xcode project — EDM4U/OneSignal iOS post-processor likely failed"
+            exit 1
           fi
+          pod install --repo-update
 
       - name: Set up iOS codesigning
         uses: OneSignal/sdk-shared/.github/actions/setup-ios-demo-codesigning@main