feat: implement /update in BaseAgent (git pull + systemctl restart)

- _do_self_update(): git pull, skip restart if already up to date,
  send result back via MQTT reply_to before restarting (2s delay)
- _get_install_dir(): derive from config path
- _get_service_name(): from config or install dir basename

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

agents_core/base_agent.py

@@ -511,9 +511,81 @@ class BaseAgent(ABC):
             all_agents = [a.agent_id for a in self.registry.all_agents()]
             return f"Agents en ligne : {online}\nAgents connus : {all_agents}"
 
+        if cmd == "update":
+            return self._do_self_update(source_msg)
+
         # Commandes custom de l'agent
         return self.handle_custom_command(cmd, args, source_msg)
 
+    # ──────────────────────────────────────────────
+    # Mise à jour self
+    # ──────────────────────────────────────────────
+
+    def _get_install_dir(self) -> str:
+        """Répertoire d'installation : parent du dossier config."""
+        return os.path.dirname(os.path.dirname(os.path.abspath(self._config_path)))
+
+    def _get_service_name(self) -> str:
+        """Nom du service systemd : depuis config ou nom du répertoire d'install."""
+        return self.config.get("service_name") or os.path.basename(self._get_install_dir())
+
+    def _do_self_update(self, source_msg: Optional[Message] = None) -> str:
+        """git pull → systemctl restart si des changements sont détectés."""
+        import subprocess
+
+        install_dir  = self._get_install_dir()
+        service_name = self._get_service_name()
+        logger.info(f"[Update] git pull dans {install_dir} (service : {service_name})")
+
+        try:
+            result = subprocess.run(
+                ["git", "pull"],
+                cwd=install_dir,
+                capture_output=True, text=True, timeout=60,
+            )
+        except Exception as e:
+            msg = f"[{self.agent_id}] ❌ git pull impossible : {e}"
+            self._send_update_reply(source_msg, msg)
+            return msg
+
+        if result.returncode != 0:
+            msg = f"[{self.agent_id}] ❌ git pull échoué :\n{result.stderr.strip()}"
+            self._send_update_reply(source_msg, msg)
+            return msg
+
+        stdout = result.stdout.strip()
+
+        if "Already up to date" in stdout:
+            msg = f"[{self.agent_id}] ✓ Déjà à jour — pas de redémarrage."
+            self._send_update_reply(source_msg, msg)
+            return msg
+
+        msg = (
+            f"[{self.agent_id}] ✓ Mis à jour :\n{stdout}\n"
+            f"Redémarrage du service {service_name}..."
+        )
+        self._send_update_reply(source_msg, msg)
+
+        # Restart différé pour laisser le temps au message MQTT d'être envoyé
+        def _restart():
+            import time
+            time.sleep(2)
+            try:
+                subprocess.run(["systemctl", "restart", service_name], timeout=30, check=True)
+            except Exception as e:
+                logger.error(f"[Update] Erreur restart {service_name} : {e}")
+
+        threading.Thread(target=_restart, daemon=True, name="update-restart").start()
+        return msg
+
+    def _send_update_reply(self, source_msg: Optional[Message], body: str):
+        """Renvoie la réponse d'update à Nexus via MQTT si possible."""
+        if source_msg and source_msg.reply_to:
+            try:
+                self.mqtt.reply(source_msg, body)
+            except Exception as e:
+                logger.debug(f"[Update] Impossible d'envoyer la réponse : {e}")
+
     # ──────────────────────────────────────────────
     # Capacités
     # ──────────────────────────────────────────────