feat: Add flushCache() export to WTM

[pankti-shah-1kosmos]

Summary

Exposes a flushCache() method from WTM.js to allow services to programmatically clear the internal HTTP response cache (NodeCache).

Change

const flushCache = () => {
    const keys = cache.keys();
    cache.flushAll();
    return keys.length;
};

Added to module.exports alongside existing executeRequest and createRequestID.

Why

WTM caches all HTTP responses (service discovery, CaaS configs, public keys) with up to 10-minute TTL. As part of the distributed cache flush feature (PL30-413), services need to clear stale WTM cached responses on demand when a cache reset signal is received via Kafka.

Impact

• 3 lines added, 1 line changed (exports)
• No changes to existing executeRequest or createRequestID behavior
• New export only — zero impact on any service until explicitly called
• Services already have a typeof WTM.flushCache === 'function' guard that will pick this up automatically

Related

• JIRA: PL30-559, PL30-413
• Admin-API PR: https://github.com/1kenterprise/nodex-admin-api/pull/335
• CaaS PR: https://github.com/1kenterprise/nodex-caas-api/pull/136

[pankti-shah-1kosmos]

Closing in favor of PR #124 targeting develop