Tests: add worker dependency recovery demo

Add a manual Docker-based regression demo for worker behavior across RabbitMQ, Redis, and MongoDB outages. The script runs an isolated test-app stack with continuous datapoint traffic and a shell mock supervisor so recovery and restart behavior can be observed without requiring a production supervisor setup.

The scenarios are independent and preserve worker/API logs per scenario, making the script useful for pre-release checks or branch comparisons while keeping it outside normal CI.

Author: xsedla1o