feat(services): run quickshell as a user service

Mirrors the unit moonarch now ships. spawn-at-startup never restarted it, so a
crash cost the bar for the rest of the session.

flake.lock

@@ -24,11 +24,11 @@
     "moonarch": {
       "flake": false,
       "locked": {
-        "lastModified": 1788173356,
-        "narHash": "sha256-SbTfjyMc5qBhatIJGPdpwqGB/1m3TV+asCM3anVl+ak=",
+        "lastModified": 1788173707,
+        "narHash": "sha256-ukAWqcRbT696x3qeDTKUdAKcdOdhv8dBS9V4kS02mtI=",
         "ref": "refs/heads/main",
-        "rev": "e5eb946f66ccfc2ff8566cbe8de1e7974aa8c4d3",
-        "revCount": 172,
+        "rev": "56eae1d81d34ad1cb6b80f69056a735d445809b5",
+        "revCount": 173,
         "type": "git",
         "url": "https://gitea.moonarch.de/nevaforget/moonarch.git"
       },

modules/services.nix

@@ -96,6 +96,21 @@
     };
   };
 
+  # The bar, launcher and every popout. A unit rather than a spawn-at-startup so
+  # a crash does not leave the session without a bar until the next login.
+  systemd.user.services.quickshell = {
+    description = "Quickshell bar and shell";
+    partOf = [ "graphical-session.target" ];
+    after = [ "graphical-session.target" ];
+    wantedBy = [ "graphical-session.target" ];
+    serviceConfig = {
+      Type = "simple";
+      ExecStart = "${lib.getExe pkgs.quickshell} -c moonarch";
+      Restart = "on-failure";
+      RestartSec = 3;
+    };
+  };
+
   # nixpkgs ships the package but no module, and the package carries no unit of
   # its own, so it is declared here. Mirrors /usr/lib/systemd/user/stasis.service.
   systemd.user.services.stasis = {