Update docs/USER_GUIDE.md

docs/USER_GUIDE.md

@@ -49,3 +49,21 @@
 
 # Architecture
 
+user
+└─> Gradio UI ──> app.py
+├─> models.py (registry)
+├─> inference.py (routing)
+├─> hf_client.py (clients)
+├─> plugins.py (extension)
+└─> deploy.py (HF Spaces)
+
+markdown
+Copy
+Edit
+
+- **Data flow**: UI → `generation_code` → `inference.chat_completion` → HF/OpenAI/Gemini/Groq → UI  
+- **Extensibility**: Add new models in `models.py`; add providers in `hf_client.py`; add integrations via `plugins/`  
+
+---
+
+That covers all test suites, CI config, and core docs. Let me know if you’d like any adjustments!