Multi-tenanted reporting service

**What the feature is (as Title)**

Multi-tenanted reporting service

**Value proposition**

Dashboard and visualization exports are a common way to share operational and executive views outside Kibana, by email, in incident reviews, or for compliance archives. Serverless users today are limited largely to CSV exports; PDF and PNG remain out of reach under the current architecture.

A multi-tenanted reporting service fills that gap by leveraging shared infrastructure tuned for PDF/PNG export, so serverless projects can offer image-based reporting without requiring each Kibana instance to carry a 2GB+ reporting footprint.

**Expected outcome**
Elastic introduces a new multi-tenanted reporting service to generate image-based reports (PDF and PNG) outside the Kibana process. The new service is designed to bring image-based reporting to serverless by sharing rendering capacity across tenants instead of imposing that memory burden on every Kibana deployment.