feat(agent): auto-renice top CPU process after 2 consecutive high-CPU reports

- Agent tracks consecutive reports above cpu_threshold (default 90%)
- After renice_consecutive reports (default 2 = 60s sustained), runs
  renice -n 19 on the top CPU process
- Reports the action back in the heartbeat payload
- Backend sends Telegram alert when renice is applied
- All params configurable in agent.yml and install.sh flags

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

rest/controllers/agent_controller.go

@@ -10,14 +10,16 @@ import (
 	"github.com/gofiber/fiber/v2"
 	"github.com/sujit-baniya/fiber-boilerplate/app"
 	"github.com/sujit-baniya/fiber-boilerplate/pkg/models"
+	"github.com/sujit-baniya/fiber-boilerplate/pkg/services"
 )
 
 // AgentHeartbeat recibe métricas del agente instalado en un servidor.
 // Ruta pública: POST /agent/heartbeat — autenticada por token en JSON body.
 func AgentHeartbeat(c *fiber.Ctx) error {
 	type HeartbeatRequest struct {
-		Token    string `json:"token"`
-		Metricas string `json:"metricas"` // JSON string ya serializado por el agente
+		Token        string `json:"token"`
+		Metricas     string `json:"metricas"`
+		ReniceAction string `json:"renice_action"`
 	}
 
 	var req HeartbeatRequest
@@ -136,6 +138,11 @@ func AgentHeartbeat(c *fiber.Ctx) error {
 		}
 	}
 
+	// Notificar por Telegram si el agente aplicó un renice
+	if req.ReniceAction != "" {
+		go services.NotificarReniceAction(servidor.Nombre, req.ReniceAction)
+	}
+
 	return c.JSON(fiber.Map{"ok": true, "servidor_id": servidor.ID})
 }