Stateful restore of active VPN connections

Feature Description

Add a dynamic "Stateful Restore / Resume Active Connections" feature to the SoftEther VPN Client.

Current Behavior

Currently, users can only choose a static "Set as Startup Connection" profile configuration. If a user manages multiple VPN profiles and dynamically connects/disconnects them throughout a session, a system crash or sudden OS reboot loses this session state. The user must manually remember and re-trigger only the connections that were active right before the reboot.

Desired Behavior

1. The SoftEther VPN Client service should continuously track or cache the names of currently active/connected VPN tunnels.
2. Upon service termination or system reboot, this active list should persist.
3. Upon service startup, the client should automatically re-establish only the specific connections that were active prior to shutdown, without forcing users to rely on static startup configurations or third-party shutdown scripts.

Use Case

This is highly beneficial for engineers and remote workers managing multiple overlapping tunnels who face unexpected reboots, system updates, or power losses and need to instantly resume their precise previous workflow state automatically.