Move UML PDF to doc/ and update .gitignore. Normalize includes,
whitespace and function signatures across headers/sources and add
concise class/function documentation. Fix RandomBot so the mine
limit is computed once and simplify DigDeepBot/SortBot mining logic.
Tidy World/Game initialization, error handling, and minor const/var
clarifications for readability and correctness
Make World::checkEffects non-const and provide its implementation.
Add RandomBot implementation and declare a private randomNumber helper.
Add a simple main() entrypoint.
fegger