ci: address Codex review on smoke test

- fix probe: failed curl emitted '000' then '|| echo 000' appended a second,
  making code='000000' so the mode=any (MCP) probe passed even when the port
  was unreachable; use a single fallback (|| true + ${code:-000})
- ensure the smoke-test-failure label exists before searching/applying, so
  de-dupe is reliable on the first failure in a fresh repo

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: graphaelli

.github/workflows/smoke-test.yml

@@ -47,7 +47,8 @@ jobs:
             local name="$1" url="$2" mode="$3"
             local code
             for i in $(seq 1 30); do
-              code="$(curl -s -o /dev/null -w '%{http_code}' --max-time 5 "$url" || echo 000)"
+              code="$(curl -s -o /dev/null -w '%{http_code}' --max-time 5 "$url" || true)"
+              code="${code:-000}"
               if [ "$mode" = "any" ] && [ "$code" != "000" ]; then
                 echo "✅ $name -> HTTP $code ($url)"; return 0
               fi
@@ -93,6 +94,24 @@ jobs:
             const runUrl = `${context.serverUrl}/${context.repo.owner}/${context.repo.repo}/actions/runs/${context.runId}`;
             const body = `The daily stack smoke test failed.\n\nRun: ${runUrl}`;
 
+            // Ensure the tracking label exists so the search below (and the
+            // de-dupe it powers) is reliable in a repo that has never had it.
+            try {
+              await github.rest.issues.getLabel({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                name: label,
+              });
+            } catch (e) {
+              if (e.status !== 404) throw e;
+              await github.rest.issues.createLabel({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                name: label,
+                color: 'd73a4a',
+              });
+            }
+
             const existing = await github.rest.issues.listForRepo({
               owner: context.repo.owner,
               repo: context.repo.repo,