P6.3: shturman.target → зонтик (Wants stage0/1/2). Новые: stage0/1/2.target,
shturman-splash.service (Before=shell, минимум зависимостей → «мгновенно»),
shturman-stage2-warmup.service (After=shell, маркер /run/shturman/stage2.ready),
tmpfiles-shturman.conf (/run/shturman). Члены critical set → stage1.target
(WantedBy+PartOf); у shell убран RuntimeDirectory (каталог теперь от tmpfiles).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Signed-off-by: Alexander <akotenev2003@gmail.com>