EVerest: ISO15118 session_setup use-after-free can crash EVSE process

EVerest is an EV charging software stack. Prior to version 2026.02.0, ISO15118_chargerImpl::handle_session_setup uses v2g_ctx after it has been freed when ISO15118 initialization fails (e.g., no IPv6 link-local address). The EVSE process can be crashed remotely by an attacker with MQTT access who issues a session_setup command while v2g_ctx has been released. Version 2026.02.0 contains a patch.