Run DNS restoration and diagnostics regressions in CI

.github/workflows/run-unit-tests.yml

@@ -137,6 +137,9 @@ jobs:
       - name: Verify MQTT start results and connection-attempt accounting
         run: python3 -B test/test_mqtt_transport_results.py -v
 
+      - name: Verify DNS lease restoration and bounded diagnostics
+        run: python3 -B test/test_network_dns.py -v
+
       - name: Verify Companion contact and channel TX routing
         run: |
           sudo apt-get update