feat: keep windowed browser video awake via wayland-pipewire-idle-inhibit

stasis ignores browser audio (pactl, browser-excluded), so windowed/muted browser video let the screen sleep. Add wayland-pipewire-idle-inhibit (AUR + user service) holding a Wayland idle-inhibitor while audio plays. Enabled on fresh installs and checked by moonarch-doctor.

scripts/moonarch-doctor

@@ -186,7 +186,7 @@ elif pacman -Qq moonarch-git &>/dev/null; then
         EXPECTED_SVCS+=("$(basename "$svc_file" .service)")
     done < <(pacman -Qql moonarch-git | grep -E '^/etc/systemd/user/[^/]+\.service$')
     # Services enabled by post-install.sh from other packages
-    EXPECTED_SVCS+=(stasis)
+    EXPECTED_SVCS+=(stasis wayland-pipewire-idle-inhibit)
 
     for svc in "${EXPECTED_SVCS[@]}"; do
         check_user_service "$svc"

scripts/post-install.sh

@@ -134,6 +134,7 @@ log "Enabling systemd user services..."
 USER_SERVICES=(
     "kanshi"
     "stasis"
+    "wayland-pipewire-idle-inhibit"
     "cliphist-text"
     "cliphist-image"
 )