Add cleanup method for graceful cleanup for Gaia (#3772)

Author: ktbyers

netmiko/checkpoint/checkpoint_gaia_ssh.py

@@ -35,6 +35,18 @@ def session_preparation(self) -> None:
         time.sleep(0.3 * self.global_delay_factor)
         self.clear_buffer()
 
+    def cleanup(self, command: str = "exit") -> None:
+        """Gracefully exit the SSH session."""
+        try:
+            if self.check_enable_mode():
+                self.exit_enable_mode()
+        except Exception:
+            pass
+        # Always try to send final 'exit' (command)
+        if self.session_log:
+            self.session_log.fin = True
+        self.write_channel(command + self.RETURN)
+
     def check_enable_mode(self, check_string: str = "#") -> bool:
         """Check if in enable mode. Return boolean."""
         return super().check_enable_mode(check_string=check_string)