ios: declare ITSAppUsesNonExemptEncryption=false (HTTPS-only, export-exempt)

App uses only standard OS-provided encryption (HTTPS via Firebase/AdMob),
which qualifies for export compliance exemption. Baking the key into
Info.plist avoids the per-build encryption prompt on future uploads.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

ios/Runner/Info.plist

@@ -22,6 +22,8 @@
 	<string>????</string>
 	<key>CFBundleVersion</key>
 	<string>$(FLUTTER_BUILD_NUMBER)</string>
+	<key>ITSAppUsesNonExemptEncryption</key>
+	<false/>
 	<key>LSRequiresIPhoneOS</key>
 	<true/>
 	<key>UILaunchStoryboardName</key>