swayidle: always restart systemd unit on failure

Occasionally, swayidle crashes with a failure to connect to the
Wayland session. Ideally, swayidle should automatically restart
instead of leaving the system in a vulnerable state.

(cherry picked from commit 50e582b9f9)

modules/services/swayidle.nix

@@ -121,6 +121,7 @@ in {
 
       Service = {
         Type = "simple";
+        Restart = "always";
         # swayidle executes commands using "sh -c", so the PATH needs to contain a shell.
         Environment = [ "PATH=${makeBinPath [ pkgs.bash ]}" ];
         ExecStart =

tests/modules/services/swayidle/basic-configuration.nix

@@ -46,6 +46,7 @@
 
     assertFileExists $serviceFile
     assertFileRegex $serviceFile 'ExecStart=.*/bin/swayidle ${expectedArgs}'
+    assertFileRegex $serviceFile 'Restart=always'
     assertFileRegex $serviceFile 'Environment=.*PATH=${
       lib.makeBinPath [ pkgs.bash ]
     }'