Research Reusable API Load Testing

[JDRkow]

Example title for issue card.

User story:
As a developer, I want to choose a reusable API load-testing tool, so that we can find API failure points.

DoD:

• Load-testing types and suitable tool candidates are summarized.
• Three tools are evaluated using C++ API and NestJS API.
• PoCs are stored in one repository.
• Each tool has an isolated devcontainer.
• All PoCs can be launched locally with a single command.
• Failure-point test results are documented for both APIs.
• Tool comparison, recommended API metrics, and the selected tool are documented.

Technical details:

1. Evaluate JMeter, Karate, and one additional candidate.
2. Run target APIs manually outside the load-testing environment.
3. Compare throughput, latency, error rate, saturation/failure point, reporting, and CI integration.