Hosted simulator shuts down when simulator-cli's stdin hits EOF (headless / CI runs)

[tobyjaguar]

Environment: KeyOS v1.4.0 (eb2c2edb3), hosted simulator built from source with SLINT_BACKEND=winit-software cargo xtask build --hosted, macOS 26 (Darwin 25.6) arm64.

What happens: running cargo xtask run --hosted with stdin closed (from a script, nohup, or a CI job) shuts the whole simulator down after about 5 s:

system service PID 26 (simulator-cli) exited -- shutting down

apps/simulator-cli reads stdin and exits on EOF, and the hosted kernel lists it as a system service, so its exit tears down every other process.

Expected: a closed stdin should leave the simulator running (the CLI is a convenience, not a dependency of the system).

Workaround: hold stdin open, e.g. tail -f /dev/null | cargo xtask run --hosted.

Suggestion: have simulator-cli idle on EOF instead of exiting, or drop it from the system-service set so its exit is not fatal.

[badicsalex]

The exit on EOF is by design for interactive shells, but I guess we can detect if stdin is interactive and not exit if it isn't.