feat(restic): limit resource usage

modules/restic.nix

@@ -0,0 +1,19 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+{
+  config = {
+    systemd.services = mapAttrs' (name: backup:
+      nameValuePair "restic-backups-${name}" ({
+        serviceConfig = {
+          CPUWeight = 25;
+          MemoryHigh = "50%";
+          MemoryMax = "75%";
+          IOWeight = 50;
+          IOSchedulingClass = "idle";
+          IOSchedulingPriority = 7;
+        };
+      })) config.services.restic.backups;
+  };
+}