journald, loki: set log retention to 3 days on host,

7 days in loki

modules/core/default.nix

@@ -7,6 +7,7 @@
 }:
 {
   imports = [
+    ./logging.nix
     ./nix.nix
     ./networking.nix
     ./terminal-tooling.nix

modules/core/logging.nix

@@ -0,0 +1,12 @@
+{
+  config,
+  pkgs,
+  lib,
+  flake,
+  ...
+}:
+{
+  services.journald.extraConfig = ''
+    MaxRetentionSec=3day
+  '';
+}

modules/loki/default.nix

@@ -57,13 +57,13 @@
           };
         };
       };
-      # Keep logs for 4 weeks
+      # Keep logs for 1 week
       # https://grafana.com/docs/loki/latest/operations/storage/retention/
       limits_config = {
         allow_structured_metadata = true;
         ingestion_rate_mb = 8;
         ingestion_burst_size_mb = 12;
-        retention_period = "4w";
+        retention_period = "1w";
         split_queries_by_interval = "0";
         volume_enabled = true;
       };