harden(regression.yml): notify step on live-regression failure — RR-03

Added notification for live-regression failures to Slack.

Author: ndrorchestration

.github/workflows/regression.yml

@@ -98,3 +98,13 @@ jobs:
           [ "$TC" -ge 30 ] \
             && echo "audit: turn_count=$TC OK" \
             || { echo "audit: turn_count=$TC < 30"; exit 1; }
+
+    - name: Notify on live-regression failure
+      if: failure()
+      run: |
+        echo "[DGAF] live-regression failed — Vercel unavailable or regression error. Suite still passing via continue-on-error."
+        if [ -n "${{ secrets.SLACK_WEBHOOK }}" ]; then
+          curl -s -X POST "${{ secrets.SLACK_WEBHOOK }}" \
+            -H 'Content-type: application/json' \
+            --data '{"text":"\u26a0\ufe0f DGAF live-regression failed (run ${{ github.run_id }}). Vercel may be unavailable. Suite overall: continue-on-error active."}'
+        fi