parser.py is a verbatim port of li3/van-li3-battery and still had the old
"000000" string gate and raw int(parts[7]) current. Apply the identical
fixes (72487cf) so the native integration and the MQTT bridge agree:
- status gate and decode_status share one parsed-int helper (0 == OK in any
representation; unparseable = unreliable)
- main-pack current parsed at its real 0.1 A scale
The 72487c MQTT/systemd/discovery/expire_after hardening intentionally does
not appear here: parser.py is protocol-only, and coordinator.py already uses
bleak_retry_connector + HA bluetooth discovery + native sensor availability
in place of those standalone concerns.