ci: add macOS app validation pipeline

scripts/ci/verify-macos-agent.sh

@@ -0,0 +1,33 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+dotnet_bin="${DOTNET_BIN:-/Users/brent/.dotnet/dotnet}"
+test_dotnet_bin="${DOTNET_TEST_BIN:-/usr/local/share/dotnet/dotnet}"
+developer_dir="${DEVELOPER_DIR:-/Applications/Xcode.app/Contents/Developer}"
+
+if [[ ! -x "${dotnet_bin}" ]]; then
+  echo "Missing Xcode 26 build SDK at ${dotnet_bin}." >&2
+  exit 2
+fi
+
+if [[ ! -x "${test_dotnet_bin}" ]]; then
+  echo "Missing .NET 9 test SDK at ${test_dotnet_bin}." >&2
+  exit 2
+fi
+
+if [[ ! -d "${developer_dir}" ]]; then
+  echo "Missing Xcode developer directory at ${developer_dir}." >&2
+  exit 2
+fi
+
+export DEVELOPER_DIR="${developer_dir}"
+
+java -version
+xcodebuild -version
+"${dotnet_bin}" --info
+"${dotnet_bin}" workload list
+DOTNET_ROOT=/usr/local/share/dotnet "${test_dotnet_bin}" --info
+
+# Signing is not required for the unsigned compile build, but report what will be
+# available to later approval-gated device and TestFlight stages.
+security find-identity -v -p codesigning || true