5.11.0

Added

• tvOS: an active PiP window now keeps the video pipeline and loopback server alive across backgrounding. tvOS previously ran an unconditional video teardown on didEnterBackground (wedge-safe: a live decode session crossing a multi-hour suspension wedged mediaserverd system-wide), which killed a system PiP window the moment the user left the app. The background handler now consults the new shouldKeepVideoAliveTV(enabled:pipActive:) policy: only pictureInPictureActive (set by the host from its PiP delegate, now cross-platform) defers the teardown, and the flag's didSet runs the wedge-safe teardown immediately when the PiP window closes while still backgrounded, so nothing crosses an idle suspension. Without active PiP, tvOS background behavior is identical to before; there is no grace window and no background-audio case on tvOS. Covered by BackgroundKeepaliveTests. (#157)