- Added a note in AGENTS.md about using `mudtool validate -w ./world` for schema validation before committing.
- Updated TESTING.md to include a checklist item for the new validation command.
- Modified smoke-tests.yml to run the world validation command as part of the CI workflow.
- Introduced a new command `validate` to check the integrity of world data, ensuring all referenced entities (NPCs, objects, guilds, races, classes, spells) exist and have valid attributes.
- Updated help message to include usage of the new command and its options.
- Added support for specifying a world directory via command line argument.
