Add performance benchmarking script

Create scripts/benchmark.sh for login throughput, dashboard API latency,
and Redis latency measurements. Accepts VIP address as argument. Manual
diagnostic tool, not added to CI.

Closes #84

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: szachovy

CHANGELOG.md

@@ -15,6 +15,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * Dependabot updates for `github-actions` and `terraform` ecosystems. (#29)
 * CI workflow to build and push service images to GitHub Container Registry on master merge. (#97)
 * Pull-first with local build fallback for container images during deployment. (#97)
+* Performance benchmarking script for login throughput and API latency. (#84)
 
 ### Changed
 

scripts/benchmark.sh

@@ -0,0 +1,45 @@
+#!/bin/bash
+
+set -euo pipefail
+
+VIP="${1:?Usage: $0 <virtual-ip-address>}"
+SUPERSET_URL="https://${VIP}"
+ITERATIONS="${2:-50}"
+
+echo "=== Superset Cluster Benchmark ==="
+echo "Target: ${SUPERSET_URL}"
+echo "Iterations: ${ITERATIONS}"
+echo
+
+echo "--- Login throughput ---"
+LOGIN_PAYLOAD='{"username":"superset","password":"cluster","provider":"db","refresh":true}'
+START=$(date +%s%N)
+for i in $(seq 1 "${ITERATIONS}"); do
+    curl --silent --insecure --output /dev/null --write-out "%{http_code} %{time_total}s\n" \
+        --url "${SUPERSET_URL}/api/v1/security/login" \
+        --header "Content-Type: application/json" \
+        --data "${LOGIN_PAYLOAD}"
+done
+END=$(date +%s%N)
+echo "Total: $(( (END - START) / 1000000 ))ms for ${ITERATIONS} requests"
+echo
+
+echo "--- Dashboard API latency ---"
+TOKEN=$(curl --silent --insecure \
+    --url "${SUPERSET_URL}/api/v1/security/login" \
+    --header "Content-Type: application/json" \
+    --data "${LOGIN_PAYLOAD}" | python3 -c "import sys,json; print(json.load(sys.stdin)['access_token'])")
+
+for endpoint in "/api/v1/dashboard/" "/api/v1/database/" "/api/v1/chart/"; do
+    echo -n "${endpoint}: "
+    curl --silent --insecure --output /dev/null --write-out "%{time_total}s\n" \
+        --url "${SUPERSET_URL}${endpoint}" \
+        --header "Authorization: Bearer ${TOKEN}"
+done
+echo
+
+echo "--- Redis latency (from mgmt node) ---"
+ssh superset@node-0 "docker exec redis redis-cli --latency-history --latency-dist -i 1 2>/dev/null | head -5" \
+    2>/dev/null || echo "Redis latency check requires SSH access to node-0"
+echo
+echo "=== Benchmark complete ==="