Adds an end-to-end SSO session-extension feature: the management server
publishes per-peer session deadlines on every Login/Sync, a new
ExtendAuthSession RPC refreshes the deadline using a fresh JWT without
tearing down the tunnel, and the daemon tracks the deadline locally so
the UI can fire a T-10min warning toast with an interactive "Extend now"
action.
CLI: new expose command to publish a local port with flags for PIN, password, user groups, custom domain, name prefix and protocol (HTTP default).
Management/API: create/renew/stop expose sessions (streamed status), automatic naming/domain, TTL renewals, background expiration, new management RPCs and client methods.
UI/API: account settings now include peer_expose_enabled and peer_expose_groups; new activity codes for peer expose events.
Zoltán Papp