feat(frontend): treat wireguard inbounds as multi-user in client actions
WireGuard has been first-class multi-client on the backend for a while (key generation, tunnel address allocation, attach/detach/delete all flow through the shared client apply path), but isInboundMultiUser still excluded it, so wireguard rows only offered Export Inbound / Reset Traffic / Clone / Delete. Adding it to the multi-user set surfaces Export All URLs (per-client .conf blocks), the subscription export, and the attach/detach/group/delete-all client actions, and makes wireguard inbounds valid targets in the attach-clients picker. The now-dead isWireguard guard on the inbound-info branch is dropped. The clients-page bulk attach/detach modals carried the same stale protocol set, also missing mtproto, so both now match the single-client form's inbound picker.