fix(mac): allow Unity app in firewall for AltTester; add lsof diagnostic

Allow Sample Unity 6 macOS.app through macOS firewall before UI tests
so AltTester server can accept connections on port 13000. On failure,
dump lsof -i :13000 to see if anything is bound.

Author: rodrigo-fournier-immutable

.github/workflows/ui-tests.yml

@@ -147,6 +147,13 @@ jobs:
           python-version: "3.13"
       - name: Install dependencies
         run: pip install -r sample-unity6/Tests/requirements-desktop.txt
+      - name: Allow Unity app through macOS firewall for AltTester
+        run: |
+          APP_PATH="${{ github.workspace }}/sample-unity6/Tests/Sample Unity 6 macOS.app"
+          if [ -d "$APP_PATH" ]; then
+            sudo /usr/libexec/ApplicationFirewall/socketfilterfw --add "$APP_PATH" 2>/dev/null || true
+            sudo /usr/libexec/ApplicationFirewall/socketfilterfw --unblockapp "$APP_PATH" 2>/dev/null || true
+          fi
       - name: Run UI tests
         env: 
           UNITY_APP_PATH: Sample Unity 6 macOS.app

sample/Tests/test/test_mac.py

@@ -178,6 +178,21 @@ def _connect_altdriver(cls):
 
         cls._dump_player_log_tail()
         cls._dump_alttester_server_log_tail()
+        try:
+            import subprocess
+            r = subprocess.run(
+                ["lsof", "-i", ":13000"],
+                capture_output=True,
+                text=True,
+                timeout=5,
+            )
+            print("----- lsof -i :13000 -----")
+            print(r.stdout or "(none)")
+            if r.stderr:
+                print(r.stderr)
+            print("----- end lsof -----")
+        except Exception as e:
+            print(f"lsof diagnostic failed: {e}")
         raise SystemExit(f"AltTester server port 13000 never opened on macOS (last host tried: {last_host_tried}).")
 
     @classmethod