garbage collection

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/adaa24fbf46737f3f1b5497bf64bae750f82942e?narHash=sha256-qhFMmDkeJX9KJwr5H32f1r7Prs7XbQWtO0h3V0a0rFY%3D' (2025-05-13)
  → 'github:NixOS/nixpkgs/910796cabe436259a29a72e8d3f5e180fc6dfacc?narHash=sha256-StSrWhklmDuXT93yc3GrTlb0cKSS0agTAxMGjLKAsY8%3D' (2025-05-31)
• Updated input 'sops-nix':
    'github:Mic92/sops-nix/e93ee1d900ad264d65e9701a5c6f895683433386?narHash=sha256-PxrrSFLaC7YuItShxmYbMgSuFFuwxBB%2Bqsl9BZUnRvg%3D' (2025-05-05)
  → 'github:Mic92/sops-nix/8d215e1c981be3aa37e47aeabd4e61bb069548fd?narHash=sha256-lAblXm0VwifYCJ/ILPXJwlz0qNY07DDYdLD%2B9H%2BWc8o%3D' (2025-05-18)

configs/container_config.nix

@@ -96,6 +96,15 @@
     };
   };
 
+  # garbage collection & optimization
+  nix.optimise.automatic = true;
+  nix.optimise.dates = [ "03:45" ]; # Optional; allows customizing optimisation schedule
+
+  nix.gc = {
+    automatic = true;
+    dates = "weekly";
+    options = "--delete-older-than 30d";
+  };
 
   # This value determines the NixOS release from which the default
   # settings for stateful data, like file locations and database versions

flake.lock

@@ -2,11 +2,11 @@
   "nodes": {
     "nixpkgs": {
       "locked": {
-        "lastModified": 1747179050,
-        "narHash": "sha256-qhFMmDkeJX9KJwr5H32f1r7Prs7XbQWtO0h3V0a0rFY=",
+        "lastModified": 1748693115,
+        "narHash": "sha256-StSrWhklmDuXT93yc3GrTlb0cKSS0agTAxMGjLKAsY8=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "adaa24fbf46737f3f1b5497bf64bae750f82942e",
+        "rev": "910796cabe436259a29a72e8d3f5e180fc6dfacc",
         "type": "github"
       },
       "original": {
@@ -43,11 +43,11 @@
         "nixpkgs": "nixpkgs_2"
       },
       "locked": {
-        "lastModified": 1746485181,
-        "narHash": "sha256-PxrrSFLaC7YuItShxmYbMgSuFFuwxBB+qsl9BZUnRvg=",
+        "lastModified": 1747603214,
+        "narHash": "sha256-lAblXm0VwifYCJ/ILPXJwlz0qNY07DDYdLD+9H+Wc8o=",
         "owner": "Mic92",
         "repo": "sops-nix",
-        "rev": "e93ee1d900ad264d65e9701a5c6f895683433386",
+        "rev": "8d215e1c981be3aa37e47aeabd4e61bb069548fd",
         "type": "github"
       },
       "original": {