Linux launcher runtime proof
Commit: 5e8f3ec0edbc2b8696f3036c9454e828185a75de
Environment: linux/x64, Node v26.12.1
Production main(); real subprocesses; synthetic runtime and manager shims.
No live service or user data used.

=== control ===
Manager unit: $HOME/.config/systemd/user/t3code.service
Service XDG_CONFIG_HOME: $HOME/.config
Committed update: 1.2.3 -> 1.2.4
BEFORE: ExecStart=$FIXTURE/control/home/.t3/runtime/versions/1.2.3/t3 __service-launcher
$ node launch.mjs  # imports production launcher main()
runtime 1.2.4: received serve; exiting fixture child
Launcher completion: Active child exited unexpectedly (0).
Manager calls:
busctl --user --json=short get-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager UnitPath
systemctl --user daemon-reload
AFTER: ExecStart=$FIXTURE/control/home/.t3/runtime/versions/1.2.4/t3 __service-launcher
unit repointed=true; daemon-reload calls=1

=== service-xdg-override ===
Manager unit: $HOME/.config/systemd/user/t3code.service
Service XDG_CONFIG_HOME: $HOME/service-config
Committed update: 1.2.3 -> 1.2.4
BEFORE: ExecStart=$FIXTURE/service-xdg-override/home/.t3/runtime/versions/1.2.3/t3 __service-launcher
$ node launch.mjs  # imports production launcher main()
runtime 1.2.4: received serve; exiting fixture child
Launcher completion: Active child exited unexpectedly (0).
Manager calls:
busctl --user --json=short get-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager UnitPath
systemctl --user daemon-reload
AFTER: ExecStart=$FIXTURE/service-xdg-override/home/.t3/runtime/versions/1.2.4/t3 __service-launcher
unit repointed=true; daemon-reload calls=1