Fix: Restore ai_agent and add Gemini Env support

ai_agent.py

@@ -8,7 +8,7 @@ from config import get_config
 def get_llm_response(prompt: str, provider: str, cfg: dict) -> str:
     """Invoca o provedor de LLM configurado."""
     if provider == "gemini":
-        api_key = cfg.get("gemini_api_key")
+        api_key = cfg.get("gemini_api_key") or os.getenv("GEMINI_API_KEY")
         url = f"https://generativelanguage.googleapis.com/v1beta/models/gemini-2.5-flash:generateContent?key={api_key}"
         payload = {"contents": [{"parts": [{"text": prompt}]}]}
         res = requests.post(url, json=payload)