Introduce `OllamaCloudProvider` that resolves the API key from configuration or the `OLLAMA_CLOUD_API_KEY` environment variable, constructs provider metadata (including timeout as numeric), and maps auth errors to `ProviderStatus::RequiresSetup`. Export the new provider in the `ollama` module. Add shared HTTP error mapping utilities (`map_http_error`, `truncated_body`) and update local provider metadata to store timeout as a number.