Until now the host had no signal handling at all: SIGTERM killed it
outright. That is fine for a host that owns nothing — but a managed
gamescope takeover owns the box's session, and on a mask-fragile display
manager (Nobara's plasmalogin) it has STOPPED that display manager for the
length of the stream. Killed there, the host leaves a box with no graphical
session and nothing left to restart it: the crash-restore state lives in
$XDG_RUNTIME_DIR, which logind removes along with the user manager, so not
even the next host start can heal it. `systemctl --user restart
punktfunk-host` mid-stream — or a package update doing it for you — was
enough to strand a box until someone reached a VT.
So SIGTERM and SIGINT now restore first and exit after. The restore runs on
a blocking thread (it shells out) under a 20s grace, well inside systemd's
TimeoutStopSec, and a host that took nothing over exits immediately.
`restore_takeover_now` is the synchronous sibling of the debounced
disconnect restore, and deliberately ignores the keep-alive policy the
latter honors: `keep_alive=forever` pins a session for the NEXT client,
which means nothing once the host that would serve them is exiting. Both
paths now share one `takeover_live()` predicate instead of repeating the
four-way "is anything ours" test.
Checked on Linux: clippy -D warnings on punktfunk-host + pf-vdisplay, tests,
rustfmt.
enricobuehler
6be865f33f