Add Ollama connection check and better error messages

main.py

@@ -276,6 +276,13 @@ async def get_llm_configuration(is_auth: bool = Depends(verify_password)):
     """Retorna configuração atual de LLMs."""
     return JSONResponse(content=get_llm_config())
 
+@app.get("/api/ollama-status")
+async def get_ollama_status(is_auth: bool = Depends(verify_password)):
+    """Verifica status do Ollama."""
+    from llm_providers import check_ollama_connection
+    result = check_ollama_connection()
+    return JSONResponse(content=result)
+
 @app.post("/api/llm-config")
 async def update_llm_configuration(config_data: dict, is_auth: bool = Depends(verify_password)):
     """Atualiza configuração de LLMs."""