We broke the OTel demo

The OpenTelemetry Demo has transitioned to version 3.0, introducing significant breaking changes such as renaming all custom attributes from `app.` to `demo.` and modularizing configuration files to improve maintainability. Alongside these structural shifts, the update introduces powerful new capabilities, including an observable "Agentic AI" stack, continuous profiling support, and OpAMP server integration for managing telemetry collectors at scale.