Decline VNC approval early when no console user is logged in

client/vnc/server/console_user_other.go

@@ -0,0 +1,7 @@
+//go:build !darwin && !windows
+
+package server
+
+// consoleHasInteractiveUser is unused outside service mode (darwin/windows)
+// but the symbol must exist so gateApproval compiles on all platforms.
+func consoleHasInteractiveUser() bool { return true }