BREAKING CHANGE: Taskmaster now requires a `.taskmasterconfig` file for model/parameter settings. Environment variables (except API keys) are no longer used for overrides.
- Throws an error if `.taskmasterconfig` is missing, guiding user to run `task-master models --setup`." -m "- Removed env var checks from config getters in `config-manager.js`." -m "- Updated `env.example` to remove obsolete variables." -m "- Refined missing config file error message in `commands.js`.