- Replace domain-specific client methods with generic get/post/patch/put/delete
- Introduce AudiobookshelfError with status_code, message, and body attributes
- Tools call client HTTP verbs directly with API paths and JSON bodies
- Rewrite test suite: 29 tests covering HTTP layer, auth injection, error handling, lifecycle, response shapes, and server integration
- Add pytest-asyncio and respx to dev dependencies
- Update requires-python to >=3.13, ruff target-version to py313
- Rename token parameter to api_key in server entry point