Add an opt-in alternative to closing LeagueClientUx: hide the managed
LeagueClientUx and Riot Client X11 windows while the game process runs and
show them again when it exits. The client stays open; the game window is
never touched.
Detection is attributed to the launcher prefix through __mldr_sockpath and
fails closed when proc, ownership or window state is unreadable. The helper
requires X11/Xwayland, restores the window on end, signal or error, and is
mutually exclusive with RCLOL_CLOSE_CLIENT_IN_GAME=1.
Document the flag, compliance scope and limits. A local 30-second test on an
i5-3470/RX 550 reduced summed client/CEF CPU from 120.7% to 93.4%; this is a
CPU-bound-host measurement, not a universal FPS claim.
No client binaries, CEF, assets or anti-cheat are modified.