ci: fix smoke test failing on curl | grep -q under pipefail

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.gitea/workflows/build-deb.yml

@@ -84,6 +84,7 @@ jobs:
 
       - name: Smoke test
         run: |
+          set -x
           apt-get install -y -qq ./out/devdesk_*.deb >/dev/null
           /usr/lib/devdesk/bin/ttyd --version
           test -s /etc/devdesk/secret.env
@@ -95,7 +96,9 @@ jobs:
           for _ in $(seq 1 30); do curl -s -o /dev/null localhost:7681/ && break; sleep 0.2; done
           code=$(curl -s -o /dev/null -w '%{http_code}' localhost:7681/)
           [ "$code" = 401 ] || { echo "expected 401 without credential, got $code"; exit 1; }
-          curl -sf -u "$DEVDESK_CREDENTIAL" localhost:7681/ | grep -q 'name="generator" content="devdesk"'
+          # Download first: `curl | grep -q` fails under pipefail (grep exits early, curl gets SIGPIPE).
+          curl -sf -u "$DEVDESK_CREDENTIAL" -o page.html localhost:7681/
+          grep -q 'name="generator" content="devdesk"' page.html
           curl -sf -u "$DEVDESK_CREDENTIAL" localhost:7681/token | jq -e '.token | length > 0'
           DEVDESK_NO_SYSTEMD=1 devdesk attach --list | jq -e '.default == "main"'
           echo "smoke test passed"