feat(testing): update test apps with generic polling and add CI/CD pipeline

- Update iOS and Android test apps with generic polling interface support
- Add testGenericPolling(), testPollingSchedule(), and testPollingResults() methods
- Include comprehensive testing of GenericPollingRequest creation and validation
- Add PollingScheduleConfig testing with cron expressions and platform adapters
- Test PollingResult handling with watermark CAS and acknowledgment flows
- Update test-apps/README.md with generic polling testing capabilities
- Add .github/workflows/ci.yml with automated testing pipeline
- Include linting, unit tests (workspaces), and k6 smoke test execution
- Add k6/poll-ack-smoke.js for fault-injection testing of poll and ack endpoints
- Support cross-platform testing with consistent TypeScript interfaces
- Include platform-specific optimizations (WorkManager, BGTaskScheduler, Service Workers)

Provides comprehensive testing infrastructure for the generic polling system.

k6/poll-ack-smoke.js

@@ -0,0 +1,62 @@
+// k6 run k6/poll-ack-smoke.js
+import http from 'k6/http';
+import { check, sleep } from 'k6';
+import { Trend, Counter } from 'k6/metrics';
+
+const latency = new Trend('api_latency');
+const throttles = new Counter('rate_limits');
+
+export const options = { vus: 5, duration: '1m' };
+
+const BASE = __ENV.API || 'https://api.endorser.ch';
+const JWT  = __ENV.JWT || 'REDACTED';
+
+function idem() { return crypto.randomUUID(); }
+
+export default function () {
+  // POLL (simulate occasional 429 / 5xx via test env or chaos flag)
+  const pollRes = http.post(
+    `${BASE}/api/v2/report/plansLastUpdatedBetween`,
+    JSON.stringify({ planIds: ['demo1','demo2'], limit: 3, afterId: __ITER === 0 ? undefined : __ENV.AFTER }),
+    {
+      headers: {
+        'Authorization': `Bearer ${JWT}`,
+        'Content-Type': 'application/json',
+        'X-Idempotency-Key': idem(),
+        'X-Client-Version': 'TimeSafari-Plugin/1.0.0'
+      },
+      tags: { endpoint: 'poll' }
+    }
+  );
+
+  latency.add(pollRes.timings.duration);
+
+  if (pollRes.status === 429) throttles.add(1);
+
+  check(pollRes, {
+    'poll: 2xx or 429/5xx with JSON': (r) => [200,429,500,503].includes(r.status) && r.headers['Content-Type']?.includes('application/json'),
+  });
+
+  if (pollRes.status === 200) {
+    const body = pollRes.json();
+    const ids = (body?.data || []).map(x => x?.planSummary?.jwtId).filter(Boolean);
+    // ACK
+    if (ids.length) {
+      const ackRes = http.post(
+        `${BASE}/api/v2/plans/acknowledge`,
+        JSON.stringify({ acknowledgedJwtIds: ids, acknowledgedAt: new Date().toISOString(), clientVersion: 'TimeSafari-Plugin/1.0.0' }),
+        {
+          headers: {
+            'Authorization': `Bearer ${JWT}`,
+            'Content-Type': 'application/json',
+            'X-Idempotency-Key': idem()
+          },
+          tags: { endpoint: 'ack' }
+        }
+      );
+      check(ackRes, { 'ack: success/idem': (r) => [200, 409].includes(r.status) });
+    }
+  }
+
+  sleep(1);
+}