Add a service to automatically fetch devshells

common/modules/home/default.nix

@@ -3,6 +3,7 @@
     ./dconf
     ./desktop-files.nix
     ./starship.nix
+    ./services.nix
     ./zsh.nix
   ];
 

common/modules/home/services.nix

@@ -0,0 +1,39 @@
+{pkgs, ...}: {
+  systemd.user.services.sync-dev-shells = {
+    Unit = {
+      Description = "Background sync for Nix dev shells repository";
+      After = ["network-online.target"];
+      Wants = ["network-online.target"];
+    };
+
+    Service = {
+      Type = "oneshot";
+      WorkingDirectory = "%h/.config/nix-shells";
+
+      ExecStart = ''
+        ${pkgs.bash}/bin/bash -c " \
+          ${pkgs.git}/bin/git pull --rebase --autostash || \
+          ${pkgs.libnotify}/bin/notify-send -u critical 'Sync Failed' 'Nix dev shells encountered a git conflict or network error.' \
+        "
+      '';
+
+      PassEnvironment = ["DBUS_SESSION_BUS_ADDRESS" "DISPLAY"];
+    };
+  };
+
+  systemd.user.timers.sync-dev-shells = {
+    Unit = {
+      Description = "Check for dev shell updates every hour";
+    };
+
+    Timer = {
+      OnBootSec = "2m";
+      OnUnitActiveSec = "1h";
+      Persistent = true;
+    };
+
+    Install = {
+      WantedBy = ["timers.target"];
+    };
+  };
+}