The panel started answering requests before the share-link generator was
registered, so an "all links", client sub-links or Telegram link request that
arrived during start-up got "sub link provider not registered". NewServer now
takes the provider and installs it before anything listens, and the provider
registry is guarded by a lock, since start-up writes it while requests read it.
A systemd stop or restart logged "Server shutdown failed: use of closed
network connection | xray is not running" on every clean exit. httpServer.Shutdown
already closes the listener, so the second Close's net.ErrClosed is now ignored,
and StopXray's not-running case is a sentinel (ErrXrayNotRunning) that Stop
treats as done.
The shipped units now use KillMode=mixed, so SIGTERM reaches only the panel,
which stops Xray and the sidecars itself; systemd still SIGKILLs whatever is left
after the stop timeout.
25f2002654
Rouzbeh†