LLM settings environment-configurable

README.md

@@ -129,6 +129,12 @@ heuristic generator remains the fallback.
 
 The FastAPI settings object also accepts `llm_provider` and `llm_model`. By
 default `llm_provider` is unset, so analysis is fully offline and deterministic.
+Environment variables use the `REPO_REGISTRY_` prefix:
+
+```bash
+REPO_REGISTRY_LLM_PROVIDER=gemini
+REPO_REGISTRY_LLM_MODEL=gemini-2.5-flash
+```
 
 ## Agent-Facing Endpoints