add an Android Quick Settings tile for starting and stopping EasyTier VPN networks
persist tile actions until the Tauri frontend is ready, so cold-start clicks are not lost
add the standard Quick Settings preferences activity alias so long-pressing the tile opens EasyTier
keep network and VPN lifecycle ownership in the existing frontend reconciliation flow
This PR fundamentally restructures the EasyTier GUI, introducing support for service mode and remote mode, transforming it from a simple desktop application into a powerful network management terminal. This change allows users to persistently run the EasyTier core as a background service or remotely manage multiple EasyTier instances, greatly improving deployment flexibility and manageability.