## Context The current `call_model` implementation sends requests to an OpenAI-compatible backend without authentication — no `Authorization` header is set. This works for local backends (MLX, Ollama) but blocks usage of hosted APIs (OpenAI, Mistral, Groq, Anthropic-compatible endpoints) which require a Bearer token. ## Work to do ### `lib/faure/config.rb` Add an optional variable: ```ruby OPENAI_API_KEY = ENV.fetch('FAURE_API_KEY', nil) ``` ### `lib/faure/codeur.rb` — `call_model` method Add the `Authorization` header when the key is present: ```ruby req['Authorization'] = "Bearer #{Config::OPENAI_API_KEY}" if Config::OPENAI_API_KEY ``` ### `ci/faure.yml` and documentation Document `FAURE_API_KEY` as an optional variable: | Variable | Required | Default | Description | |---|---|---|---| | `FAURE_API_KEY` | No | — | Bearer token for the OpenAI-compatible API. Leave empty for unauthenticated local backends. | ## Expected result - Local backends (MLX, Ollama) continue to work without any changes - Hosted APIs (OpenAI, Mistral, Groq, etc.) work by setting `FAURE_API_KEY` - Single code path — no duplication