CoreManager.RunProcess decided sudo elevation from the live mutable
_config.TunModeItem.EnableTun while the launched config was generated
from the immutable CoreConfigContext snapshot. If the TUN state changed
while a reload was in flight, a core whose config contains a TUN
inbound could launch without elevation and die within the 100ms health
check ("Failed to run core"), with no stderr shown.
The elevation decision now follows context.IsTunEnabled /
preContext.IsTunEnabled, so the generated config and the launch mode
always agree. With legacy TUN protect, the sing-box pre-core hosting
TUN is elevated and the main core no longer runs as root needlessly.
sing-box requires realm.server_url as a full URL (https://host:port).
Bare host:port caused "missing host in realm server_url" on import.
Also forward stun_servers and clear ResolveRealm success message.
Fixes#9635
hyjhyj111