Implement built-in cron worker

module.nix

@@ -28,13 +28,6 @@ in
         default = "root";
       };
 
-      scanTimer = mkOption {
-        type = types.str;
-        description = "The systemd's timer interval when the app will be performing the scan for new tasks";
-        example = "*-*-* *:00";
-        default = "*-*-* *:10";
-      };
-
       config = mkOption {
         type = types.attrs;
         description = "The obsidian-tasks-reminder config which will be eventually converted to yaml";
@@ -56,46 +49,17 @@ in
     config = mkIf cfg.enable {
       environment.systemPackages = [app];
 
-      systemd.timers.obsidian-tasks-reminder-scanner = {
-        description = "Scan for new Obsidian tasks";
-        wantedBy = ["timers.target"];
-
-        timerConfig = {
-          OnCalendar = cfg.scanTimer;
-          Unit = "obsidian-tasks-reminder-scanner.service";
-        };
-      };
-
-      systemd.timers.obsidian-tasks-reminder = {
-        description = "Notify about Obsidian tasks";
-        wantedBy = ["timers.target"];
-
-        timerConfig = {
-          OnCalendar = "*-*-* *:*:00";
-          Unit = "obsidian-tasks-reminder.service";
-        };
-      };
-
-      systemd.services.obsidian-tasks-reminder-scanner = {
-        description = "Scan for new Obsidian tasks";
-
-        serviceConfig = {
-          Type = "oneshot";
-          User = cfg.user;
-        };
-
-        script = "${app}/bin/obsidian-tasks-reminder -s";
-      };
-
       systemd.services.obsidian-tasks-reminder = {
-        description = "Notify about Obsidian tasks";
+        enable = true;
+        description = "Obsidian Tasks Notifier";
+
+        wantedBy = ["network-online.target"];
+        after = ["network-online.target"];
 
         serviceConfig = {
-          Type = "oneshot";
+          ExecStart = "${app}/bin/obsidian-tasks-reminder";
           User = cfg.user;
         };
-
-        script = "${app}/bin/obsidian-tasks-reminder -n";
       };
     };
   }