feat(ci): add automated post-deploy production rollout verification (#39)

### Summary of Changes

- **Version Metadata Generation**:
- `ci/docker/www/Dockerfile` & `ci/docker/docs/Dockerfile` accept
`COMMIT_SHA` and `VERSION` build args and write
`/usr/share/nginx/html/version.json`.
- `ci/config/nginx/default.conf` configures `location = /version.json`
with `Cache-Control: no-store, no-cache, must-revalidate` so
verification is never stale.
- **Automated Rollout Verification**:
  - `.github/workflows/services-www-releases-dispatch-release.yml`
  - `.github/workflows/services-docs-next-required.yml`
  - `.github/workflows/services-www-next-required.yml`
- Added `verify-rollout` job that polls
`https://www.ermnvldmr.com/version.json` and
`https://docs.ermnvldmr.com/version.json` with 10s intervals (up to 5
minutes) to ensure the commit actively rolls out to users.

.github/workflows/services-docs-next-required.yml

@@ -89,6 +89,9 @@ jobs:
           push: true
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
+          build-args: |
+            COMMIT_SHA=sha-$(echo ${{ github.sha }} | cut -c1-7)
+            VERSION=sha-$(echo ${{ github.sha }} | cut -c1-7)
 
   deploy:
     name: Deploy - Kubernetes (GitOps)
@@ -113,3 +116,47 @@ jobs:
         run: |
           DOCS_TAG="sha-$(echo ${{ github.sha }} | cut -c1-7)"
           bash ci/scripts/deploy-gitops.sh docs "${DOCS_TAG}"
+
+  verify-rollout:
+    name: Verify - Production Rollout
+    needs: deploy
+    runs-on: ubuntu-latest
+    if: github.event_name == 'push' && github.ref == 'refs/heads/next'
+    steps:
+      - name: Await production rollout
+        run: |
+          TARGET_COMMIT="sha-$(echo ${{ github.sha }} | cut -c1-7)"
+          ENDPOINT="https://docs.ermnvldmr.com/version.json"
+
+          echo "========================================================"
+          echo "Verifying production deployment on $ENDPOINT"
+          echo "Expected commit: $TARGET_COMMIT"
+          echo "========================================================"
+
+          MAX_ATTEMPTS=30
+          ATTEMPT=1
+
+          while [ $ATTEMPT -le $MAX_ATTEMPTS ]; do
+            echo "Attempt $ATTEMPT/$MAX_ATTEMPTS: Polling $ENDPOINT..."
+
+            RESPONSE=$(curl -sf --max-time 10 "$ENDPOINT" 2>/dev/null || true)
+
+            if [ -n "$RESPONSE" ]; then
+              LIVE_COMMIT=$(echo "$RESPONSE" | jq -r '.commit // empty')
+
+              echo "  Live commit: ${LIVE_COMMIT:-<none>}"
+
+              if [ "$LIVE_COMMIT" = "$TARGET_COMMIT" ]; then
+                echo "✅ Success! Production docs has successfully rolled out $TARGET_COMMIT."
+                exit 0
+              fi
+            else
+              echo "  Endpoint did not return valid JSON or timed out."
+            fi
+
+            ATTEMPT=$((ATTEMPT + 1))
+            sleep 10
+          done
+
+          echo "❌ Deployment verification timed out after 5 minutes."
+          exit 1