Port forwarding no longer shares the filter client. FilterClient keeps only
filter capabilities, and forwarding gets its own adapter, service and boot
replay:
- utils/firewall/forwarding holds the provider adapters. firewalld uses native
forward-port, ufw and iptables share the NAT implementation moved out of
client/iptables/forward.go.
- service/forwarding.go owns base info, search, operate, enable and replay.
The API keeps its routes and dispatches on name/type/operate.
- init/firewall replays forwarding through that service instead of loading NAT
rule files inline.
Also adds 1PANEL_FORWARD to the IptablesOp name enum: the frontend already
sends {"name":"1PANEL_FORWARD","operate":"init-forward"} and the validator
rejected it with 400 before reaching the service. Besides that, the only
observable difference is that a forward-tab search no longer triggers the
port/address record cleanup goroutine on the side.
