fix: mover alerta de coste a /generate donde está el gasto real

src/bot/bot.py

@@ -112,23 +112,8 @@ 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(
@@ -382,6 +367,18 @@ async def cmd_generate(update: Update, ctx: ContextTypes.DEFAULT_TYPE):
         else:
             await send_chunked(update.message, output)
 
+        try:
+            stats = await db.get_usage_stats(session_id)
+            total_cost = sum(s.get("total_cost", 0) for s in stats)
+            if total_cost > settings.cost_alert_threshold:
+                await update.message.reply_text(
+                    f"⚠️ Coste acumulado de esta sesión: `${total_cost:.4f}`"
+                    f" (umbral: `${settings.cost_alert_threshold:.2f}`)",
+                    parse_mode=ParseMode.MARKDOWN
+                )
+        except Exception:
+            pass
+
     except Exception as e:
         logger.error("Generate failed", error=str(e))
         await update.message.reply_text(f"❌ Generation failed: {str(e)[:200]}")