Update CI script for latest macOS and Xcode

.github/workflows/ci.yml

@@ -1,15 +1,58 @@
 name: CI
 
-on: [push]
+on:
+  push:
+  pull_request:
 
 jobs:
-  build:
-
+  test:
+    name: iOS Simulator Tests
     runs-on: macos-latest
 
     steps:
-    - uses: actions/checkout@v1
-    - name: Run all of the library unit tests.
-      run: '(curl -s -L https://tim.dev/install_ios_oss_ci | bash -s arg1 arg2) && bundle exec fastlane test'
-      env:
-        TEST_SCHEME: "TOFileSystemObserverTests"
+      - uses: actions/checkout@v4
+
+      - name: Show Xcode and SDK versions
+        run: |
+          xcodebuild -version
+          xcrun --show-sdk-version --sdk iphonesimulator
+
+      - name: Select latest iPhone simulator
+        id: simulator
+        run: |
+          DEVICE=$(xcrun simctl list devices available | \
+                   grep -oE 'iPhone [0-9]+( Pro( Max)?)?' | \
+                   sort -V | tail -n 1)
+          if [ -z "$DEVICE" ]; then
+            echo "No iPhone simulator found. Available devices:"
+            xcrun simctl list devices available
+            exit 1
+          fi
+          echo "Selected simulator: $DEVICE"
+          echo "device=$DEVICE" >> "$GITHUB_OUTPUT"
+
+      - name: Pre-boot simulator
+        # Cold-boot the simulator before running tests so file-coordination and
+        # presenter system services are ready by the time NSFilePresenter-driven
+        # integration tests start. Skipping this makes those tests flake on CI
+        # even though they pass reliably locally.
+        run: xcrun simctl bootstatus "${{ steps.simulator.outputs.device }}" -b
+
+      - name: Run tests
+        run: |
+          set -o pipefail
+          xcodebuild test \
+            -project TOFileSystemObserverExample.xcodeproj \
+            -scheme TOFileSystemObserverTests \
+            -destination "platform=iOS Simulator,name=${{ steps.simulator.outputs.device }},OS=latest" \
+            -resultBundlePath TestResults.xcresult \
+            -test-iterations 3 \
+            -retry-tests-on-failure \
+            CODE_SIGNING_ALLOWED=NO
+
+      - name: Upload test results
+        if: failure()
+        uses: actions/upload-artifact@v4
+        with:
+          name: test-results
+          path: TestResults.xcresult