feat(verification): add k6 load test script and execution guide to README

scripts/load_test.js

@@ -0,0 +1,48 @@
+import http from 'k6/http';
+import { check } from 'k6';
+
+export const options = {
+  scenarios: {
+    // Ramp up from 10 to 50 virtual users pushing sustained load
+    sustained_load: {
+      executor: 'ramping-vus',
+      startVUs: 10,
+      stages: [
+        { duration: '10s', target: 50 },  // Ramp up to 50 VUs
+        { duration: '30s', target: 50 },  // Stay at 50 VUs (~1,000+ req/s)
+        { duration: '5s', target: 0 },    // Ramp down
+      ],
+    },
+  },
+  thresholds: {
+    http_req_duration: ['p(95)<50'], // 95% of API responses under 50ms
+    http_req_failed: ['rate<0.01'],  // Less than 1% failure
+  },
+};
+
+export default function () {
+  const url = __ENV.API_URL || 'http://localhost:8000/api/v1/cdr/raw';
+  const payload = JSON.stringify({
+    raw_id: `load-${__VU}-${__ITER}-${Date.now()}`,
+    src_ip: '10.240.1.1',
+    device_id: '310410998877665',
+    caller_num: '+19875551234',
+    svc: '4G_DATA',
+    up_bytes: 1048576,
+    down_bytes: 4194304,
+    rat: 6,
+    lac: '4021',
+    ci: '8812',
+    epoch_start: 1726070000,
+    epoch_end: 1726070300,
+  });
+
+  const params = {
+    headers: { 'Content-Type': 'application/json' },
+  };
+
+  const res = http.post(url, payload, params);
+  check(res, {
+    'status is 202 or 429': (r) => r.status === 202 || r.status === 429,
+  });
+}