Skeletons First

The core principle is that the developer who has no knowledge of the system can implement methods/properties etc. following only documentation in the skeleton - think its like you are a designer defining the task for the implementer.

Do as follows:
- Read .windsurf/rules/do-write-concise-methods.md
- Read .windsurf/rules/keep-docstrings-consistent.md
- Create class and method/function stubs and document them
- Include full docstrings, return types (eg "-> list[str]", and sample return values (per global rules)
- Use raise NotImplementedError() in each method.
- Do not skip type hints or documentation
- Add comments inside the methods pointing attention to the logic flow, exception handling, logging etc.