feat: working E2E container stack with Node-RED + InfluxDB + Grafana

- Fix Dockerfile.e2e to install EVOLV properly in Node-RED /data/
- Add measurement node E2E test flow with scaling (4-20mA to 0-5m)
- Add Grafana health check to run-e2e.sh
- Guard pumpingStation demo IIFE with require.main check
- All 10 EVOLV nodes load successfully in containerized Node-RED

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

test/e2e/run-e2e.sh

@@ -127,6 +127,36 @@ else
     FAILURES=$((FAILURES + 1))
 fi
 
+# --- Step 5b: Verify Grafana is reachable ---
+log_info "Checking Grafana health..."
+GRAFANA_HEALTH=$(curl -sf "http://localhost:3000/api/health" 2>&1) || {
+    log_error "Failed to reach Grafana health endpoint"
+    FAILURES=$((FAILURES + 1))
+}
+
+if echo "$GRAFANA_HEALTH" | grep -q '"database":"ok"'; then
+    log_info "  [PASS] Grafana is healthy"
+else
+    log_error "  [FAIL] Grafana health check failed"
+    FAILURES=$((FAILURES + 1))
+fi
+
+# --- Step 5c: Verify EVOLV measurement node produced output ---
+log_info "Checking EVOLV measurement node output in container logs..."
+NODERED_LOGS=$(eval $DOCKER_COMPOSE -f "$COMPOSE_FILE" logs nodered 2>&1)
+
+if echo "$NODERED_LOGS" | grep -q "Database Output"; then
+    log_info "  [PASS] EVOLV measurement node produced database output"
+else
+    log_warn "  [WARN] EVOLV measurement node output not detected in logs"
+fi
+
+if echo "$NODERED_LOGS" | grep -q "Process Output"; then
+    log_info "  [PASS] EVOLV measurement node produced process output"
+else
+    log_warn "  [WARN] EVOLV measurement process output not detected in logs"
+fi
+
 # --- Step 6: Summary ---
 echo ""
 if [ $FAILURES -eq 0 ]; then