- Switch to `ollama-rs` crate for chat, model listing, and streaming.
- Remove custom request building, authentication handling, and debug logging.
- Drop unsupported tool conversion; now ignore tool descriptors with a warning.
- Refactor model fetching to use local model info and optional cloud details.
- Consolidate error mapping via `map_ollama_error`.
- Update health check to use the new HTTP client.
- Delete obsolete `provider_interface.rs` test as the provider interface has changed.