feat: add OOM-related service configuration

templates/etc/systemd/user/subapp.service.j2

@@ -37,6 +37,15 @@ PIDFile=/run/subapp/subapp_bagit.pid
 # Do not kill any processes for a save shutdowns with a valid SubApp database.
 KillMode=none
 
+### Stability features
+# DEACTIVATED FOR DEBIAN 10, AS SYSTEMD DOESN'T SEEM TO SUPPORT THEM YET.
+# documented at "man (5) systemd.service" and
+# https://www.freedesktop.org/software/systemd/man/systemd.service.html
+#OOMPolicy=stop
+# documented at "man (5) systemd.exec" and
+# https://www.freedesktop.org/software/systemd/man/systemd.exec.html
+OOMScoreAdjust=-900
+
 ### Security features
 # documented at https://www.freedesktop.org/software/systemd/man/systemd.exec.html
 # DEACTIVATED FOR DEBIAN 10, AS SYSTEMD DOESN'T SEEM TO SUPPORT THEM YET.