Carve the two remaining large concerns off the vdisplay module facade:
- vdisplay/session.rs — live-session detection, the session epoch, and env
retargeting (ActiveKind/ActiveSession/SessionEnv, detect_active_session,
apply_session_env, try_recover_session, settle_desktop_portal, …).
- vdisplay/routing.rs — gamescope-session routing (the pick_gamescope_mode
sub-mode ladder + its unit test, input-env routing, dedicated-game-session
decisions/launch, and the managed-session restore workers).
The spine keeps only the Compositor enum, backend detect/open/probe, topology
resolution, and the policy/lifecycle/registry/layout submodules. Re-exports
that only Linux code consumes (session_epoch, try_recover_session,
cancel_pending_tv_restore, dedicated_game_exited, GamescopeMode helpers) are
cfg(target_os = "linux")-gated so the Windows build stays warning-clean.
Pure move; no behavior change. Linux clippy+tests and Windows host clippy
(nvenc,amf-qsv) both green.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
