Enhance macOS provisioning profile handling in build scripts and documentation

This commit updates the check_signing_identities.sh script to search for provisioning profiles in multiple common directories, improving the detection process. Additionally, the README_MAS.md is updated to clarify where provisioning profiles are stored in newer Xcode versions and provides guidance on locating the correct profile for Mac App Store builds. This enhances the overall usability and clarity for developers working with macOS builds.

build_tools/macos/check_signing_identities.sh

@@ -137,10 +137,23 @@ EOF
 echo
 
 echo "==> [$(ts)] Provisioning profiles (Mac App Store builds require one)"
-prof_dir="${HOME}/Library/MobileDevice/Provisioning Profiles"
-if [[ -d "${prof_dir}" ]]; then
-  ls -la "${prof_dir}" | head -n 50
-else
-  echo "(none found at '${prof_dir}')"
+prof_dirs=(
+  "${HOME}/Library/Developer/Xcode/UserData/Provisioning Profiles"
+  "${HOME}/Library/MobileDevice/Provisioning Profiles"
+)
+any_prof=0
+for prof_dir in "${prof_dirs[@]}"; do
+  if [[ -d "${prof_dir}" ]]; then
+    any_prof=1
+    echo "  ${prof_dir}"
+    ls -la "${prof_dir}" | head -n 20
+    echo
+  fi
+done
+if [[ "$any_prof" -eq 0 ]]; then
+  echo "(no provisioning profile directories found in common locations)"
 fi
 
+echo "Tip: to pick the right MAS profile for a bundle id, run:"
+echo "  ./build_tools/macos/find_mas_provisioning_profile.sh --bundle-id com.dryark.strawberry"
+