[NFR-05] Design for scalability

[manuelgrabmayer]

Requirement:
The system shall be scalable to accommodate growth in data volume and additional geographic regions.

Goal:
Ensure the prototype architecture can grow beyond the first DACH-focused dataset.

Acceptance criteria:

1. Expected scalability bottlenecks are identified.
2. Data model and pipeline design do not hard-code only one country or source.
3. The architecture can support additional sources.
4. The dashboard structure can support additional regions.
5. Scalability limitations are documented.