Adds native xiaomi-mimo provider configuration, auth/env aliases, model registry entries, TUI request handling, tests, and docs. Keeps credentials in existing provider-scoped config/env/keyring paths and uses placeholders only in docs.
- Add docs/PROVIDERS.md placeholder reference in README and CONFIGURATION.md
- Update provider lists to include moonshot, openrouter, novita
- Add MOONSHOT_API_KEY/KIMI_API_KEY env var docs
- Update default_text_model entries for all providers
- Change legacy deepseek-cn alias to deepseek
- Add CODEWHALE_PROVIDER as preferred env var name
AdityaG