feat: alerta de coste — aviso si sesión supera COST_ALERT_THRESHOLD

src/bot/bot.py

@@ -112,8 +112,23 @@ async def run_scheduled_research(bot, chat_id: int, topic: str,
                     f"🔍 Investigación completada — analizando novedades…"
                 )
             else:
+                async def get_session_cost(session_id: int) -> float:
+                    try:
+                        stats = await db.get_usage_stats(session_id)
+                        return sum(s.get("total_cost", 0) for s in stats)
+                    except Exception:
+                        return 0.0
+
+                session_cost = await get_session_cost(session_id)
+                cost_warning = ""
+                if session_cost > settings.cost_alert_threshold:
+                    cost_warning = (
+                        f"\n⚠️ Coste: ${session_cost:.4f}"
+                        f" (umbral: ${settings.cost_alert_threshold:.2f})"
+                    )
                 await reporter.done(
                     f"✅ Listo — `{scraped}` fuentes · `{chunk_count}` chunks · usa /generate <tipo>"
+                    f"{cost_warning}"
                 )
         else:
             await reporter.done(